Hybrid/All Purpose/Compromise Suspension Setup
#1
Hybrid/All Purpose/Compromise Suspension Setup
I've been avoiding lowering my 4x4 '87 TA:
https://www.thirdgen.org/forums/susp...ml#post6237874
because I haven't had time to mess with a few things (weight jacks and lowering spindles/brakes). Well last Friday I drove it to the gym and it suddenly started handling funny and I lost the front right brake, it turned out that the front right strut burst. I've seen them leak before, this made a bang and covered everything including the brakes with hydraulic fluid:
So it's time to do something about it.
The reality is that I build everything like a road race car but 70% of the time it's a street car and for years now I rarely road race/autox more than once a year. 90% of the time it gets raced it's at the dragstrip.
Being realistic, what I want:
- I miss how my '83 looked, that had a F fender height <25" and R around 25.5 with 26.1 and 27.1" tall tires. I want it low with the front lower than the back
- Something that will outhandle 99% of what is on the street, competent enough that I won't need to make excuses at an Autox/Road course
- Something that will do well at the dragstrip with a tire change, strut adjustment and maybe some minor tweaks (airbags in the rear springs, disconnect the front sway bar... type stuff)
What I have/what is staying:
- '87 TA, V8/manual trans (for now at least), it's a fairly light combination in the front (aluminum heads, no AC and other stuff gone, 'glass hood...)
- Rear suspension: HEAVY Moser 9" rear with a nodular center section, detroit locker, 35 spline axles, 4th gen rear brakes, adjustable everything- LCA pivots, PHR pivots on both sides, adjustable LCA and PHR, shorter custom TA similar to a jegster adjustable with different brackets/mounts, Koni yellow shocks.
- tires, street/handling: 265/40-17 (25.4" tall) and 295/35-18 (26.1" tall) on ZO6 rims
- tires, drag: 26x10.5 Hoosier slicks (actually almost 27" tall) and some VW skinnies, occasionially some modified firebird rims with 275/60-15 DR's and assorted front skinny tires.
Front suspension- pretty much everything goes, the parts that I intend to put on now (all new):
- Koni Yellow struts
- UMI LCA's (Delrin bushings...), I'm debating trying to find some extended ball joints for them
- Caster/camber plates (I think I have both UMI and Founders sitting in boxes somewhere)
- solid tie rod sleeves and whatever front steering linkage parts it needs, I recently rebuilt the steering box and at the time the rest of the linkage was OK
Undecided:
- what springs- What I have sitting around- I have the springs from the '83 TA that sat in the weeds sitting around (cut WS6 springs with spring isolators to get the ride height right, unmolested '87 TA (WS6 also) springs which I can cut, Eibach Pros (new in box), Eibach pros (used, about 1/3 of the bottom of front coils broke off in the pockets after a season of autox, it was weird, I would trim them to an even length if I used these). Assorted factory springs that i could cut to whatever, would consider buying if there is a perfect spring out there
- front sway bars- 34 and 36mm hollow and 32 solid. On my '83 I REALLY liked the 32 solid, I'm hoping that the 34 hollow is similar and want to use that
- rear sway bars- I have an assortement from I think 18mm to the fairly rare 25mm factory bar. I want to use the 25mm just for the advantage at the dragstrip. I may try set that up for preload at the dragstrip.
- for the same reason I currently have some air bags in the rear springs (suck them flat when not at the dragstrip) that i'll likely keep for L/R tuning at the dragstrip if the 25mm bar does not keep it flat enough.
What I have that is not going on now but will likely in the future:
- Weight jacks (don't quite have these thought out enough to make me happy, I may be persuaded to change my mind, but I don't want to have the car disassembled more than a weekend so I'd have to have them worked out and fabricated before I took it apart).
- UMI tubular K-member
- Drop spindles (I need to finalize some details/finish welding and figure out some brake mounting brackets, a no go right now, I can't have the car disassembled long enough to do this)
https://www.thirdgen.org/forums/susp...ml#post6237874
because I haven't had time to mess with a few things (weight jacks and lowering spindles/brakes). Well last Friday I drove it to the gym and it suddenly started handling funny and I lost the front right brake, it turned out that the front right strut burst. I've seen them leak before, this made a bang and covered everything including the brakes with hydraulic fluid:
So it's time to do something about it.
The reality is that I build everything like a road race car but 70% of the time it's a street car and for years now I rarely road race/autox more than once a year. 90% of the time it gets raced it's at the dragstrip.
Being realistic, what I want:
- I miss how my '83 looked, that had a F fender height <25" and R around 25.5 with 26.1 and 27.1" tall tires. I want it low with the front lower than the back
- Something that will outhandle 99% of what is on the street, competent enough that I won't need to make excuses at an Autox/Road course
- Something that will do well at the dragstrip with a tire change, strut adjustment and maybe some minor tweaks (airbags in the rear springs, disconnect the front sway bar... type stuff)
What I have/what is staying:
- '87 TA, V8/manual trans (for now at least), it's a fairly light combination in the front (aluminum heads, no AC and other stuff gone, 'glass hood...)
- Rear suspension: HEAVY Moser 9" rear with a nodular center section, detroit locker, 35 spline axles, 4th gen rear brakes, adjustable everything- LCA pivots, PHR pivots on both sides, adjustable LCA and PHR, shorter custom TA similar to a jegster adjustable with different brackets/mounts, Koni yellow shocks.
- tires, street/handling: 265/40-17 (25.4" tall) and 295/35-18 (26.1" tall) on ZO6 rims
- tires, drag: 26x10.5 Hoosier slicks (actually almost 27" tall) and some VW skinnies, occasionially some modified firebird rims with 275/60-15 DR's and assorted front skinny tires.
Front suspension- pretty much everything goes, the parts that I intend to put on now (all new):
- Koni Yellow struts
- UMI LCA's (Delrin bushings...), I'm debating trying to find some extended ball joints for them
- Caster/camber plates (I think I have both UMI and Founders sitting in boxes somewhere)
- solid tie rod sleeves and whatever front steering linkage parts it needs, I recently rebuilt the steering box and at the time the rest of the linkage was OK
Undecided:
- what springs- What I have sitting around- I have the springs from the '83 TA that sat in the weeds sitting around (cut WS6 springs with spring isolators to get the ride height right, unmolested '87 TA (WS6 also) springs which I can cut, Eibach Pros (new in box), Eibach pros (used, about 1/3 of the bottom of front coils broke off in the pockets after a season of autox, it was weird, I would trim them to an even length if I used these). Assorted factory springs that i could cut to whatever, would consider buying if there is a perfect spring out there
- front sway bars- 34 and 36mm hollow and 32 solid. On my '83 I REALLY liked the 32 solid, I'm hoping that the 34 hollow is similar and want to use that
- rear sway bars- I have an assortement from I think 18mm to the fairly rare 25mm factory bar. I want to use the 25mm just for the advantage at the dragstrip. I may try set that up for preload at the dragstrip.
- for the same reason I currently have some air bags in the rear springs (suck them flat when not at the dragstrip) that i'll likely keep for L/R tuning at the dragstrip if the 25mm bar does not keep it flat enough.
What I have that is not going on now but will likely in the future:
- Weight jacks (don't quite have these thought out enough to make me happy, I may be persuaded to change my mind, but I don't want to have the car disassembled more than a weekend so I'd have to have them worked out and fabricated before I took it apart).
- UMI tubular K-member
- Drop spindles (I need to finalize some details/finish welding and figure out some brake mounting brackets, a no go right now, I can't have the car disassembled long enough to do this)
Last edited by 83 Crossfire TA; 10-25-2022 at 12:32 AM.
#2
re: Hybrid/All Purpose/Compromise Suspension Setup
Suggestions?
What I'm mainly looking for is:
- how hard should I try to get extended ball joints for this thing? Between the hassle about getting boots for them, the current thread about the right ball joint size for them, and the fact that when I get around to putting the drop spindles on the car I'll have to go back to stock height ones makes me wonder if I just leave them for now
- I'd like to run the 34mm hollow front bar (I'm not a big fan of really stiff sway bars, my favorite 3rd gen combinations have always had smaller than the typical 36mm that everyone uses) and 25mm rear bar (despite not liking big sway bars, I'm hoping to use it as sort of a compromise drag bar, plus this thing always has MUCH bigger rear tires on it which tend to play nice with bigger bars, 9" is heavy/a lot to control...). Will I be able to make this work/how? Traditionally without some suspension geometry changes, this would cause a car that wants to swing the back end out in hard turns, a handful on a track/autox, dangerous on the street.
- Springs- Front, honestly I want to go as soft as I can get away with (a little more reaction at the dragstrip, a little nicer on the street, but I'll put up with more if I have to). I'm guessing that might be in the 7xx pound range maybe, but likely more.
Rear I'm somewhat lost with. A lot of aftermarket lowering springs for these cars come with progressive coils, back when I did a lot of Autox and RR I never liked them I found the soft/hard change disconcerting when I changed input/went across the center. On the street progressive rate springs were a nicer ride till your backend bottomed and then everything went to ****. I found specific rate factory rear springs cut to height (spring isolators removed so the rate didn't go up as high) the best for racing and although bumpier in daily driving they never really bottomed. OTOH, Dean has been hinting at some special progressive rear setup (Dean, you want to explain and tell me if I can make it work here?), and the Moser axle rear spring pockets are mounted higher than stock ones so I'll likely have to trim any rear springs I try to make them work- I'm worried that any factory rear springs will never get short enough without the spring rates going to high (I've never managed to get my hands on V6 springs to see if they are actually softer), so maybe taking a set of progressive rate eibachs and trimming them might get the rate up high enough to prevent them from bottoming on big bumps and make this whole thing work?
What I'm mainly looking for is:
- how hard should I try to get extended ball joints for this thing? Between the hassle about getting boots for them, the current thread about the right ball joint size for them, and the fact that when I get around to putting the drop spindles on the car I'll have to go back to stock height ones makes me wonder if I just leave them for now
- I'd like to run the 34mm hollow front bar (I'm not a big fan of really stiff sway bars, my favorite 3rd gen combinations have always had smaller than the typical 36mm that everyone uses) and 25mm rear bar (despite not liking big sway bars, I'm hoping to use it as sort of a compromise drag bar, plus this thing always has MUCH bigger rear tires on it which tend to play nice with bigger bars, 9" is heavy/a lot to control...). Will I be able to make this work/how? Traditionally without some suspension geometry changes, this would cause a car that wants to swing the back end out in hard turns, a handful on a track/autox, dangerous on the street.
- Springs- Front, honestly I want to go as soft as I can get away with (a little more reaction at the dragstrip, a little nicer on the street, but I'll put up with more if I have to). I'm guessing that might be in the 7xx pound range maybe, but likely more.
Rear I'm somewhat lost with. A lot of aftermarket lowering springs for these cars come with progressive coils, back when I did a lot of Autox and RR I never liked them I found the soft/hard change disconcerting when I changed input/went across the center. On the street progressive rate springs were a nicer ride till your backend bottomed and then everything went to ****. I found specific rate factory rear springs cut to height (spring isolators removed so the rate didn't go up as high) the best for racing and although bumpier in daily driving they never really bottomed. OTOH, Dean has been hinting at some special progressive rear setup (Dean, you want to explain and tell me if I can make it work here?), and the Moser axle rear spring pockets are mounted higher than stock ones so I'll likely have to trim any rear springs I try to make them work- I'm worried that any factory rear springs will never get short enough without the spring rates going to high (I've never managed to get my hands on V6 springs to see if they are actually softer), so maybe taking a set of progressive rate eibachs and trimming them might get the rate up high enough to prevent them from bottoming on big bumps and make this whole thing work?
#3
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Car: '89 Formula
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re: Hybrid/All Purpose/Compromise Suspension Setup
Mark,
Trying to live in two worlds at once, means you don't live in either. We all still try to do it, myself included.
Application and focus are critical to enjoying the final product. I built for highway use (most nimble from a 65 mph roll) and incorporated as much RR as I could. I still want my creature comforts on the highway. I don't think RR parts and street parts are incompatible while allowing for different settings, of course.
If you want the front low, you must address the RC issue. To me, ext BJ's and rear PHBRB on axle side are no-brainers, cheap as far as part cost outlay, and a little work. This is the best thing to address: too low front RC and too high rear RC. I have both ext BJ's and drop spindles. I don't believe it's possible to raise the front RC too high on our cars (within reason).
Dean expressed thoughts that I went too soft with #850 front springs. They are still considered stiff but on the lower end of the stiff category. I can do this because of LS2, some front weight reduction, AND a higher front RC allows for a little softer spring. Conversely, when you lower the rear RC, you should stiffen the rear springs. How much is up to you and your SB choice (mine: 19mm bar, #250 coilover, w/12 bolt w/Eaton LS).
If you cut progressive springs, you will not know the rates; AND, you have a Detroit Locker! I paid big money to stay away from Moser (DTS and Strange will use Moser axles). I hope it works for you.
Personally, I would install the WJ's and Drop Spindles that you have in hand while apart (and ext BJ's). No need to worry about front spring height ever again. With an iron V8, you should at least be in the #800's, and you're wanting a slightly lesser front bar, too. You have to get that fr RC up, or limit travel with a stiff spring, else your RC will be below ground when you hit the brakes. You also have Koni Yellows and new plates. You get the front where you want it, then match the back to the front.
Keep the stock k-member, except for drag. Aftermarket is OK for longitudinal forces, but the stock is great for diagonal (turning), and adds weight below the CG which also helps resist roll. Can't live in both worlds, here.
If street determines 95% of use, then build a fun handling car. You can visit a track and have fun, too. Fun is the common denominator. Too many modify for a specific use, loose the fun quotient, and sell-off after a while. This 3rd Gen platform is a fun car to drive (I hear this often from people who recall owning one) and can be an all-around performer if you keep focus on that.
Trying to live in two worlds at once, means you don't live in either. We all still try to do it, myself included.
Application and focus are critical to enjoying the final product. I built for highway use (most nimble from a 65 mph roll) and incorporated as much RR as I could. I still want my creature comforts on the highway. I don't think RR parts and street parts are incompatible while allowing for different settings, of course.
If you want the front low, you must address the RC issue. To me, ext BJ's and rear PHBRB on axle side are no-brainers, cheap as far as part cost outlay, and a little work. This is the best thing to address: too low front RC and too high rear RC. I have both ext BJ's and drop spindles. I don't believe it's possible to raise the front RC too high on our cars (within reason).
Dean expressed thoughts that I went too soft with #850 front springs. They are still considered stiff but on the lower end of the stiff category. I can do this because of LS2, some front weight reduction, AND a higher front RC allows for a little softer spring. Conversely, when you lower the rear RC, you should stiffen the rear springs. How much is up to you and your SB choice (mine: 19mm bar, #250 coilover, w/12 bolt w/Eaton LS).
If you cut progressive springs, you will not know the rates; AND, you have a Detroit Locker! I paid big money to stay away from Moser (DTS and Strange will use Moser axles). I hope it works for you.
Personally, I would install the WJ's and Drop Spindles that you have in hand while apart (and ext BJ's). No need to worry about front spring height ever again. With an iron V8, you should at least be in the #800's, and you're wanting a slightly lesser front bar, too. You have to get that fr RC up, or limit travel with a stiff spring, else your RC will be below ground when you hit the brakes. You also have Koni Yellows and new plates. You get the front where you want it, then match the back to the front.
Keep the stock k-member, except for drag. Aftermarket is OK for longitudinal forces, but the stock is great for diagonal (turning), and adds weight below the CG which also helps resist roll. Can't live in both worlds, here.
If street determines 95% of use, then build a fun handling car. You can visit a track and have fun, too. Fun is the common denominator. Too many modify for a specific use, loose the fun quotient, and sell-off after a while. This 3rd Gen platform is a fun car to drive (I hear this often from people who recall owning one) and can be an all-around performer if you keep focus on that.
#4
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iTrader: (20)
re: Hybrid/All Purpose/Compromise Suspension Setup
To be honest, a simple adjustable shock like koni and semi stiff springs work surprisingly well for drag. Not optimal but certainly manageable for a guy who goes a few times a year
I got into the 1.28-1.29 60 ft range on stock sways, eibach prokit and tokico illumina 5 adjustables lol. Some of that is power management but also good track and tire. Car handled fun enough for me on the street.
I got into the 1.28-1.29 60 ft range on stock sways, eibach prokit and tokico illumina 5 adjustables lol. Some of that is power management but also good track and tire. Car handled fun enough for me on the street.
#5
re: Hybrid/All Purpose/Compromise Suspension Setup
Yea I haven't gone as much recently but I'm hoping to get this thing to where I make 50 or more passes a year.
I got into the 1.28-1.29 60 ft range on stock sways, eibach prokit and tokico illumina 5 adjustables lol. Some of that is power management but also good track and tire. Car handled fun enough for me on the street.
Right now I'm wondering how far Koni yellows could be pushed before I need to consider something like Viking shocks... but I'm pretty sure that you can build a mostly handling oriented 9s 3rd gen that only gives up a couple of 10ths in the quarter on good drag tires.
#6
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Car: 88 Formula 350
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re: Hybrid/All Purpose/Compromise Suspension Setup
I built my iroc very similar to what you have planned with slight variations, and I seem to build my cars the same as you. I drive mine on the street 90% of the time and even take trips.
My Formula: Tokico Illumina 5 way struts with matching drop springs, Spohn LCARB, LCAs, Adjustable Torque Arm, SFC.
Iroc seems to be closer to what you are thinking...
SFC, Ground Control Weight Jacks, Koni Yellow, R compound 265/35/18, Founders LCARB, LCAs, Adjustable Torque Arm, Panhard bar, UMI Tubular A-Arms.
They both handle great and I enjoy them. I'm running stock sway bars on both with poly bushings. Looking like I have some reading to do on the extended ball joints.
My Formula: Tokico Illumina 5 way struts with matching drop springs, Spohn LCARB, LCAs, Adjustable Torque Arm, SFC.
Iroc seems to be closer to what you are thinking...
SFC, Ground Control Weight Jacks, Koni Yellow, R compound 265/35/18, Founders LCARB, LCAs, Adjustable Torque Arm, Panhard bar, UMI Tubular A-Arms.
They both handle great and I enjoy them. I'm running stock sway bars on both with poly bushings. Looking like I have some reading to do on the extended ball joints.
#7
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re: Hybrid/All Purpose/Compromise Suspension Setup
If you go that often, In that case maybe some viking or double adjustable strange may be a good investment
Higher power car wont need much weight transfer so you can have tighter shocks and stiffer springs. So thats good for the handling side of things.
But i am willing to bet a koni can go really far if your lca angle is adjustable for anti squat and you run a bigger rear sway bar
I know some guys like large front bar and smaller rear now a days with alot of spring rate. Drag car wants a bigger rear bar to leave evenly. Stock 24mm worked ok for me, i was def twisted but handling was still great. I never took off my front 36 mm bar
Higher power car wont need much weight transfer so you can have tighter shocks and stiffer springs. So thats good for the handling side of things.
But i am willing to bet a koni can go really far if your lca angle is adjustable for anti squat and you run a bigger rear sway bar
I know some guys like large front bar and smaller rear now a days with alot of spring rate. Drag car wants a bigger rear bar to leave evenly. Stock 24mm worked ok for me, i was def twisted but handling was still great. I never took off my front 36 mm bar
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#8
re: Hybrid/All Purpose/Compromise Suspension Setup
Mark,
Trying to live in two worlds at once, means you don't live in either. We all still try to do it, myself included.
Application and focus are critical to enjoying the final product. I built for highway use (most nimble from a 65 mph roll) and incorporated as much RR as I could. I still want my creature comforts on the highway. I don't think RR parts and street parts are incompatible while allowing for different settings, of course.
Trying to live in two worlds at once, means you don't live in either. We all still try to do it, myself included.
Application and focus are critical to enjoying the final product. I built for highway use (most nimble from a 65 mph roll) and incorporated as much RR as I could. I still want my creature comforts on the highway. I don't think RR parts and street parts are incompatible while allowing for different settings, of course.
I know what I'm getting into- my '83 TA was essentially a dedicated AutoX/Road Race car that I both daily drove AND took to the dragstrip almost EVERY Friday night. I'm 20some years older now, but that just means that I know how to do it better, have more good parts laying around and don't HAVE to drive it daily unless I want to/think it would be fun.
I look at this mostly like working out the finer suspension details but I have a pretty good idea where I want to end up. Honestly, the big compromise that in this car that I can't figure out is the seats- I'd love to put something nice in it like late model GTO seats but I can't justify the weight. Of course, I'm only making about 500hp in it now, when that goes up enough I may be willing to put heavy seats in it
If you want the front low, you must address the RC issue. To me, ext BJ's and rear PHBRB on axle side are no-brainers, cheap as far as part cost outlay, and a little work. This is the best thing to address: too low front RC and too high rear RC. I have both ext BJ's and drop spindles. I don't believe it's possible to raise the front RC too high on our cars (within reason).
I've been pretty careful with selecting parts (including what I'm going to use with the eventual drop spindles) so i can still bolt on modified factory 15" firebird wheels. It's just a look that I want to be able to go to at times (I've modified a set to have 15x4 fronts and 15x9.5" rears, I'm looking for another set to turn into 4 15x9.5's so I can run old school fat tires on all 4 corners on what will look like factory wheels).
Dean expressed thoughts that I went too soft with #850 front springs. They are still considered stiff but on the lower end of the stiff category. I can do this because of LS2, some front weight reduction, AND a higher front RC allows for a little softer spring.
Why did Dean feel that your front springs were too soft? What was the expected negative of them being that soft?
I had 890# front spring rates on my '83 and considered them quite acceptable for a daily driver but I'm hoping by raising the front RC and lightening the front end some I can go a little lighter.
Conversely, when you lower the rear RC, you should stiffen the rear springs. How much is up to you and your SB choice (mine: 19mm bar, #250 coilover, w/12 bolt w/Eaton LS).
If you cut progressive springs, you will not know the rates; AND, you have a Detroit Locker! I paid big money to stay away from Moser (DTS and Strange will use Moser axles). I hope it works for you.
If you cut progressive springs, you will not know the rates; AND, you have a Detroit Locker! I paid big money to stay away from Moser (DTS and Strange will use Moser axles). I hope it works for you.
- Back in the day I worked at a shop that was a moser dealer so I could get their stuff at cost
- I've broken 9 sets of gears/axles/posis drag racing previous "road race" f-bodies... No more, I wanted bulletproof
- it was actually bought for a different project that went away, things would have been spec'ed differently for this car
If it wasn't for those 3 things I probably would have gone with something more like an S60 with a more street oriented posi. This thing is HEAVY and obnoxious, but I won't break it.
That said, much like the front end, I'm hoping that lowering the rear RC will let me go stiffer in the back for better dragstrip (the 25mm rear bar) and to prevent the bottoming you can get on the street trying to keep the rear spring rates soft enough.
I've made these cars work well over the years with very stiff fronts and very soft rears, in this case I'm hoping that I can manpulate RC's and go not so stiff front and stiffer rear and end up with something that handles as well but is both more streetable and does better at the dragstrip.
Personally, I would install the WJ's and Drop Spindles that you have in hand while apart (and ext BJ's). No need to worry about front spring height ever again.
And it would likely be exactly the same springs as I would run right now without the WJ and DS.
I could probably get the WJ worked out right now, but that puts me in a no-man's land with the springs. I would either need to go out and buy shorter springs that would be shorter than I really would want to run with the DS, or I don't know what. I really intend to build them into the K-member's top spring buckets so it would make sense to just do them then, although I guess I could probably make something temporarily drop in with the stock K-member. I don't like how when you make something temporary it tends to turn permanent...
With an iron V8, you should at least be in the #800's, and you're wanting a slightly lesser front bar, too. You have to get that fr RC up, or limit travel with a stiff spring, else your RC will be below ground when you hit the brakes. You also have Koni Yellows and new plates. You get the front where you want it, then match the back to the front.
To be honest I've been worried that I can get the rear RC down too much/front up too much, sounds like you don't think it's possible. I know that Dean has hinted at this a few times, and has only been recommending lowring one side of the PHB and only using 1/2" extended BJ's
Keep the stock k-member, except for drag. Aftermarket is OK for longitudinal forces, but the stock is great for diagonal (turning), and adds weight below the CG which also helps resist roll. Can't live in both worlds, here.
If street determines 95% of use, then build a fun handling car. You can visit a track and have fun, too. Fun is the common denominator. Too many modify for a specific use, loose the fun quotient, and sell-off after a while. This 3rd Gen platform is a fun car to drive (I hear this often from people who recall owning one) and can be an all-around performer if you keep focus on that.
I know that what I'm building is not what I would recommend to anyone building a streetcar, and it's not by far the easiest way to go fast at the dragstrip, but it is what makes me happy. You know, that look you get when you have a "sane" person in the passenger seat, the t-tops off, you take a ramp at 3x the speed limit and think nothing of it... they try to scream but they can't, go white-knuckled grabbing anything they can hold on to and are silent for the rest of the ride, you get to where you're going and "I am never going anyplace with you driving again."
#9
Re: Hybrid/All Purpose/Compromise Suspension Setup
I used to post a lot here on thirdgen before I just got tired of the signal to noise ratio, especially in some of the other forums, I got involved in the FB groups and then just stopped when the whole blowup happened on MM (which was ridiculous considering how many local people know the car, have seen me run at the track/video, have known me for years, I documented with pictures everything I did to it...). I guess I'm getting more involved here, but for the most part what I'm building/when I'm running... has been flying under the radar for a while now.
Higher power car wont need much weight transfer so you can have tighter shocks and stiffer springs. So thats good for the handling side of things.
But i am willing to bet a koni can go really far if your lca angle is adjustable for anti squat and you run a bigger rear sway bar
But i am willing to bet a koni can go really far if your lca angle is adjustable for anti squat and you run a bigger rear sway bar
I know some guys like large front bar and smaller rear now a days with alot of spring rate. Drag car wants a bigger rear bar to leave evenly. Stock 24mm worked ok for me, i was def twisted but handling was still great. I never took off my front 36 mm bar
#10
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re: Hybrid/All Purpose/Compromise Suspension Setup
Mark,
I used QA1 1210-209P in Spohn adj a-arms. These QA1 units are re-buildable and you can re-set pre-load while on the car. I lengthened the rear ear of a-arms by 9/16" to give a little more caster and bring the wheel forward just slightly - it looks better in the fender arc. Nut is the original position and you can see how much thread is left on the shank, when I pulled it entirely out. For boots, I re-used what came with Spohn a-arms. There was a small wire around the base, I snipped it, but it still snapped into place on the QA1's and is still there today. Also, I have AFCO swivel cup WJ's from Speedway w/Eibach 9.5" x 5.5" DD #850 springs. DSE has quite good WJ's that are reversible (not permanent), but they cost. Same swivel design, too.
No problem with clearance - I have stock 8" wheels. I recall that when Dean went to Turkey to set-up Burk's car (similar front end as mine), Burk used an 8.5" wheel up front. I'm confident that will work, not sure about 9". With Drop Spindles, you won't be able to go above 255 or so. But scrub radius is poor to begin with. A street car, and road race car, will do better longevity wise with a 245. Also, with drops and lightweight wheel assembly, you just might have better control thus better tire contact patch - or at least even. "The Grip" threads were about how close a 245 with drops was vs 275 with just ext BJ's. 30mm can seem like a lot, but the actual contact patch is thin with fully inflated tires. If the wheel can be better controlled with less harsh rebound, one could possibly equal the 275. And uneven wear with the 275 scrub radius will effect tire temps, too - more weight = harsher rebound. AutoX is a different story. Better compound selection in 17 x 245, better cost - a lot of little things start to add up to making them on par with 275's w/no drop spindles. But you have to have the drop spindles - they actually saved me #1.5 pounds over stock (Racecraft RR version is no longer available).
Production cars tend to have exaggerated roll axis inclination - front RC at pavement level and rear RC up at say 12". That incline front to back needs to be flattened out. There are practical considerations and ride quality considerations to take into account in doing this.
When raising/lowering the front RC, you get practically 1:1 effect. You raise one inch, you get RC raised one inch. The rear is NOT 1:1.
When we lower our cars, the CG is lowered - good thing. But, this roll axis inclination becomes more exaggerated than at stock ride height - front RC goes down equal amount that was lowered, but rear RC does not go down equal amount so the inclination becomes more exaggerated. It needs to be corrected or you could have a worse handling car than before lowering. When the CG and roll axis are closer together (very good thing), you have less force being transferred (force remains distributed better on all four tires). This is keeping a smaller moment arm - the smaller the arm, the less force transferred as it acts like a lever upon the roll axis.
With better balance on all four and less force transfer, we can use less harsh springs, and dampers, and maybe sway bars. Plus, ride quality will be better as less rebound is being used (along with unsprung weight improvements). You still do want force transfer onto the tire(s) that need it the most during maneuvers, though. We are not trying to eliminate, but to control it and use it to advantage.
On the rear, Viking is OK. I prefer RideTech, but they cost more - see next post. You get what you pay for in shocks. I said plates because I shortened the caster/camber plates.
Brian
I used QA1 1210-209P in Spohn adj a-arms. These QA1 units are re-buildable and you can re-set pre-load while on the car. I lengthened the rear ear of a-arms by 9/16" to give a little more caster and bring the wheel forward just slightly - it looks better in the fender arc. Nut is the original position and you can see how much thread is left on the shank, when I pulled it entirely out. For boots, I re-used what came with Spohn a-arms. There was a small wire around the base, I snipped it, but it still snapped into place on the QA1's and is still there today. Also, I have AFCO swivel cup WJ's from Speedway w/Eibach 9.5" x 5.5" DD #850 springs. DSE has quite good WJ's that are reversible (not permanent), but they cost. Same swivel design, too.
No problem with clearance - I have stock 8" wheels. I recall that when Dean went to Turkey to set-up Burk's car (similar front end as mine), Burk used an 8.5" wheel up front. I'm confident that will work, not sure about 9". With Drop Spindles, you won't be able to go above 255 or so. But scrub radius is poor to begin with. A street car, and road race car, will do better longevity wise with a 245. Also, with drops and lightweight wheel assembly, you just might have better control thus better tire contact patch - or at least even. "The Grip" threads were about how close a 245 with drops was vs 275 with just ext BJ's. 30mm can seem like a lot, but the actual contact patch is thin with fully inflated tires. If the wheel can be better controlled with less harsh rebound, one could possibly equal the 275. And uneven wear with the 275 scrub radius will effect tire temps, too - more weight = harsher rebound. AutoX is a different story. Better compound selection in 17 x 245, better cost - a lot of little things start to add up to making them on par with 275's w/no drop spindles. But you have to have the drop spindles - they actually saved me #1.5 pounds over stock (Racecraft RR version is no longer available).
Production cars tend to have exaggerated roll axis inclination - front RC at pavement level and rear RC up at say 12". That incline front to back needs to be flattened out. There are practical considerations and ride quality considerations to take into account in doing this.
When raising/lowering the front RC, you get practically 1:1 effect. You raise one inch, you get RC raised one inch. The rear is NOT 1:1.
When we lower our cars, the CG is lowered - good thing. But, this roll axis inclination becomes more exaggerated than at stock ride height - front RC goes down equal amount that was lowered, but rear RC does not go down equal amount so the inclination becomes more exaggerated. It needs to be corrected or you could have a worse handling car than before lowering. When the CG and roll axis are closer together (very good thing), you have less force being transferred (force remains distributed better on all four tires). This is keeping a smaller moment arm - the smaller the arm, the less force transferred as it acts like a lever upon the roll axis.
With better balance on all four and less force transfer, we can use less harsh springs, and dampers, and maybe sway bars. Plus, ride quality will be better as less rebound is being used (along with unsprung weight improvements). You still do want force transfer onto the tire(s) that need it the most during maneuvers, though. We are not trying to eliminate, but to control it and use it to advantage.
On the rear, Viking is OK. I prefer RideTech, but they cost more - see next post. You get what you pay for in shocks. I said plates because I shortened the caster/camber plates.
Brian
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re: Hybrid/All Purpose/Compromise Suspension Setup
Ron Sutton text on RideTech Shocks:
JRI is the best racing shock. In my experience JRI racing shocks provide more tire grip than any other shock made. The only two cons are price & that they need to be rebuilt with seals sooner. That’s a minor thing when winning performance is the goal. The Ridetech shocks provide the best grip of what I consider to be street shocks. The level of grip, while greater than any other street shock I have experienced, is not in the same league as JRI race shock grip. One is a race shock & the other is a street shock. Unless something damages the shock, the Ridetechs will not need to be rebuilt with new seals for a long, long time.
Both are very tunable & responsive to tuning changes. Both can be valved with “linear/digressive”, “digressive/linear” & “high-zero-number” valving curves. Those traits are key to achieving the secret sauce valving I do to achieve the most grip possible from the shocks. The JRI shocks will accept significantly stiffer “high-zero-number” valving while still being responsive & maintaining grip. With the JRI shocks, we can tie the front end down longer … for longer corners. This is not an issue for autocross, but does come into play for road courses. For this reason, I supply Ridetech Triple Adjustable shocks (with my special valving) standard on my AutoX-Star front suspensions. For my Track-Star front suspensions, JRI double adjustable shocks (with my special valving) are standard.
When I first started exploring the PT scene, I saw that Ridetech was very popular and didn't really know why, as I had not heard of them in the racing world I came from. Over the last year, I've gotten to look at a lot of shock valving curves from almost all of the PT Shock manufacturers. After some dyno testing & revalving Ridetech shocks of our own, the picture got clear. There are many factors that define the actual real world handling & ride characteristics of a shock. The dyno curve is one of them. It’s an important one, but just one of several factors.
The factors that matter most to the ride & handling are:
1. Piston design - defines the valving curves possible, responsiveness,
2. Piston seal & friction - self explanatory
3. Bleed valving - controls the initial shock responsiveness control
4. Valving control – in most cases a stack of special shims that deflect & define the oil flow through the piston
5. Adjustability range - To tune or adjust for very different situations like track & street
6. Rebound & compression bleed over - how much does one adjustment affect the other valving
7. Body & overall shock design – affects how it manages the pressure, control & responsiveness
8. Stiction (from piston seal & shock bore surface) = pressure required to get the shock to initially respond
9. Internal rod/shaft pressure - affects initial shock responsiveness
I’m sure I left some things out, but you get the idea. Items 1, 2, 3, 4 play the biggest role in the valving curve. Items 5 & 6 define the range & accuracy of tuning. Items 7-9 define how well the shock can keep the tire gripping the asphalt over irregular surfaces.
Other things matter too, like ...
• Is it rebuildable?
• Is it revalvable?
• Parts availability?
• Tech support?
• Customer service?
• Warranty?
• Return/repair policy?
• And lastly initial purchase price & TCO ... total cost of operation.
What I learned about the Ridetech shock … and I hope I’m not sharing any of their trade secrets … are:
a. By running larger bleed valve orifices
b. Combined with stiffer main valving from the piston & shim stack
c. Inside an extremely well designed shock
d. Provides the best balance of ride comfort over irregular surfaces & bumps … and handling control with heavy cars in cornering situations.
Other perks or benefits of their design are:
e. Wide range of effective adjustability
f. Very low pressure bleed over
g. Fully rebuildable
h. Easy to revalve for different curves
I have experienced good parts availability, tech support & customer service. Since I don’t own a set of Ridetech shocks on a street car, I can not personally vouch for the million mile warranty or their return/repair policy … but I hear great things from their customers. Where the rubber meets the road for most guys is initial purchase price. I am super impressed with how much shock you get for your money. In my opinion, the Ridetech shocks are the best shock in their price range by far. Nothing that costs the same as the Ridetech shocks can compare to the quality & performance of this shock. It is a heck of a value.
JRI is the best racing shock. In my experience JRI racing shocks provide more tire grip than any other shock made. The only two cons are price & that they need to be rebuilt with seals sooner. That’s a minor thing when winning performance is the goal. The Ridetech shocks provide the best grip of what I consider to be street shocks. The level of grip, while greater than any other street shock I have experienced, is not in the same league as JRI race shock grip. One is a race shock & the other is a street shock. Unless something damages the shock, the Ridetechs will not need to be rebuilt with new seals for a long, long time.
Both are very tunable & responsive to tuning changes. Both can be valved with “linear/digressive”, “digressive/linear” & “high-zero-number” valving curves. Those traits are key to achieving the secret sauce valving I do to achieve the most grip possible from the shocks. The JRI shocks will accept significantly stiffer “high-zero-number” valving while still being responsive & maintaining grip. With the JRI shocks, we can tie the front end down longer … for longer corners. This is not an issue for autocross, but does come into play for road courses. For this reason, I supply Ridetech Triple Adjustable shocks (with my special valving) standard on my AutoX-Star front suspensions. For my Track-Star front suspensions, JRI double adjustable shocks (with my special valving) are standard.
When I first started exploring the PT scene, I saw that Ridetech was very popular and didn't really know why, as I had not heard of them in the racing world I came from. Over the last year, I've gotten to look at a lot of shock valving curves from almost all of the PT Shock manufacturers. After some dyno testing & revalving Ridetech shocks of our own, the picture got clear. There are many factors that define the actual real world handling & ride characteristics of a shock. The dyno curve is one of them. It’s an important one, but just one of several factors.
The factors that matter most to the ride & handling are:
1. Piston design - defines the valving curves possible, responsiveness,
2. Piston seal & friction - self explanatory
3. Bleed valving - controls the initial shock responsiveness control
4. Valving control – in most cases a stack of special shims that deflect & define the oil flow through the piston
5. Adjustability range - To tune or adjust for very different situations like track & street
6. Rebound & compression bleed over - how much does one adjustment affect the other valving
7. Body & overall shock design – affects how it manages the pressure, control & responsiveness
8. Stiction (from piston seal & shock bore surface) = pressure required to get the shock to initially respond
9. Internal rod/shaft pressure - affects initial shock responsiveness
I’m sure I left some things out, but you get the idea. Items 1, 2, 3, 4 play the biggest role in the valving curve. Items 5 & 6 define the range & accuracy of tuning. Items 7-9 define how well the shock can keep the tire gripping the asphalt over irregular surfaces.
Other things matter too, like ...
• Is it rebuildable?
• Is it revalvable?
• Parts availability?
• Tech support?
• Customer service?
• Warranty?
• Return/repair policy?
• And lastly initial purchase price & TCO ... total cost of operation.
What I learned about the Ridetech shock … and I hope I’m not sharing any of their trade secrets … are:
a. By running larger bleed valve orifices
b. Combined with stiffer main valving from the piston & shim stack
c. Inside an extremely well designed shock
d. Provides the best balance of ride comfort over irregular surfaces & bumps … and handling control with heavy cars in cornering situations.
Other perks or benefits of their design are:
e. Wide range of effective adjustability
f. Very low pressure bleed over
g. Fully rebuildable
h. Easy to revalve for different curves
I have experienced good parts availability, tech support & customer service. Since I don’t own a set of Ridetech shocks on a street car, I can not personally vouch for the million mile warranty or their return/repair policy … but I hear great things from their customers. Where the rubber meets the road for most guys is initial purchase price. I am super impressed with how much shock you get for your money. In my opinion, the Ridetech shocks are the best shock in their price range by far. Nothing that costs the same as the Ridetech shocks can compare to the quality & performance of this shock. It is a heck of a value.
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re: Hybrid/All Purpose/Compromise Suspension Setup
Yup, thought I answered your questions in the thread, so I wasn't going to type twice.
I'm not comfortable with more than a 1" ext BJ. Not saying it can't be done safely, just think there are better ways (like drop spindles). Especially with heavier wheels like 17's or more. Just my opinion, though.
You can go too low on the rear RC, if you use brackets on both sides. Like Dean has mentioned, once you lower the car, you can get by with the axle side only and just use the first hole or two. No one needs more than that for street. If you start to use the lower holes, then the PB is nowhere near level and then should use both brackets. CAUTION should be exercised when lowering the PHB alot. This could help drag racing, but I don't do that so I haven't studied it.
Is your TA off the trans?
Yeah, I've been reading Tibo's thread on UMI arms. Ramey is a knowledgeable guy, but I felt his excuse/explanation was a little weak even if plausible. Fitment has always been a problem in the aftermarket, and running a business these days is difficult, too. What's a customer to do, but solve it and keep moving on. I think we all have stories to tell. We don't like to admit it; but, there's a cost of doing business on the customer side, too. At least it's solvable.
When Dean thought I was just a little soft on fr spring rates, he probably didn't recall my particular car's set-up. He can't be expected to remember everyone's car. He's lurking somewhere.
To recap:
1. Get your ride height set (WJ's are vital tool)
2. Improve the roll axis inclination as best as possible (DS, ext BJ, PHB axle bracket)
3. You already have Koni yellow struts and strut mounts
4. #800's range of fr spring will give some travel, but not a lot. With fr RC improvements you shouldn't go too low on braking. With no fr RC improvements I would suggest #950 or a little more to limit travel.
5. A quality adj rear coilover - you'll need multiple springs (#200 & 250 FOR rr and street, no advice for drag) and bars (SB - 24 & 19mm, adj LCA, adj TA, & adj PHB) for the rear as you change between different driving events.
6. Wheel assemblies, brakes, and tires we haven't discussed. Could be drastic from drag to RR. I'm a foursquare guy, but Dean has suggested that fr 245 and rr 275 is perfectly fine - Burk's BBC has that. With 500rwhp, it makes some sense. For street it's fine (don't usually push that hard), but RR usually likes all 4. I'm on the fence and waiting.
I'm not comfortable with more than a 1" ext BJ. Not saying it can't be done safely, just think there are better ways (like drop spindles). Especially with heavier wheels like 17's or more. Just my opinion, though.
You can go too low on the rear RC, if you use brackets on both sides. Like Dean has mentioned, once you lower the car, you can get by with the axle side only and just use the first hole or two. No one needs more than that for street. If you start to use the lower holes, then the PB is nowhere near level and then should use both brackets. CAUTION should be exercised when lowering the PHB alot. This could help drag racing, but I don't do that so I haven't studied it.
Is your TA off the trans?
Yeah, I've been reading Tibo's thread on UMI arms. Ramey is a knowledgeable guy, but I felt his excuse/explanation was a little weak even if plausible. Fitment has always been a problem in the aftermarket, and running a business these days is difficult, too. What's a customer to do, but solve it and keep moving on. I think we all have stories to tell. We don't like to admit it; but, there's a cost of doing business on the customer side, too. At least it's solvable.
When Dean thought I was just a little soft on fr spring rates, he probably didn't recall my particular car's set-up. He can't be expected to remember everyone's car. He's lurking somewhere.
To recap:
1. Get your ride height set (WJ's are vital tool)
2. Improve the roll axis inclination as best as possible (DS, ext BJ, PHB axle bracket)
3. You already have Koni yellow struts and strut mounts
4. #800's range of fr spring will give some travel, but not a lot. With fr RC improvements you shouldn't go too low on braking. With no fr RC improvements I would suggest #950 or a little more to limit travel.
5. A quality adj rear coilover - you'll need multiple springs (#200 & 250 FOR rr and street, no advice for drag) and bars (SB - 24 & 19mm, adj LCA, adj TA, & adj PHB) for the rear as you change between different driving events.
6. Wheel assemblies, brakes, and tires we haven't discussed. Could be drastic from drag to RR. I'm a foursquare guy, but Dean has suggested that fr 245 and rr 275 is perfectly fine - Burk's BBC has that. With 500rwhp, it makes some sense. For street it's fine (don't usually push that hard), but RR usually likes all 4. I'm on the fence and waiting.
#15
re: Hybrid/All Purpose/Compromise Suspension Setup
Yup, thought I answered your questions in the thread, so I wasn't going to type twice.
I'm not comfortable with more than a 1" ext BJ. Not saying it can't be done safely, just think there are better ways (like drop spindles). Especially with heavier wheels like 17's or more. Just my opinion, though.
I'm not comfortable with more than a 1" ext BJ. Not saying it can't be done safely, just think there are better ways (like drop spindles). Especially with heavier wheels like 17's or more. Just my opinion, though.
#16
re: Hybrid/All Purpose/Compromise Suspension Setup
You can go too low on the rear RC, if you use brackets on both sides. Like Dean has mentioned, once you lower the car, you can get by with the axle side only and just use the first hole or two. No one needs more than that for street . If you start to use the lower holes, then the PB is nowhere near level and then should use both brackets. CAUTION should be exercised when lowering the PHB alot.
This could help drag racing, but I don't do that so I haven't studied it.
Is your TA off the trans?
Yeah, I've been reading Tibo's thread on UMI arms. Ramey is a knowledgeable guy, but I felt his excuse/explanation was a little weak even if plausible. Fitment has always been a problem in the aftermarket, and running a business these days is difficult, too. What's a customer to do, but solve it and keep moving on. I think we all have stories to tell. We don't like to admit it; but, there's a cost of doing business on the customer side, too. At least it's solvable.
In the end it doesn't really matter, I'll make it work with or without support from them, but I will chalk them up as another aftermarket company that on some level doesn't have their engineering/manufacturing stuff together and at this point I would like to figure out what that problem is in case I do need to deal with them again.
When Dean thought I was just a little soft on fr spring rates, he probably didn't recall my particular car's set-up. He can't be expected to remember everyone's car. He's lurking somewhere.
To recap:
1. Get your ride height set (WJ's are vital tool)
1. Get your ride height set (WJ's are vital tool)
Not sure what I'm thinking about the back yet. I don't remember anything up inside the pocket that prevents more conventional WJ's back there but it seems like everyone goes with the sleeve/coilover adjuster on the seat there... not sure what is in the way of something more conventional. Either way that's not nearly as pressing, since you can get at that with about 10 minutes worth of work and that is what swapping rear springs, different spring isolators... takes.
2. Improve the roll axis inclination as best as possible (DS, ext BJ, PHB axle bracket)
3. You already have Koni yellow struts and strut mounts
4. #800's range of fr spring will give some travel, but not a lot. With fr RC improvements you shouldn't go too low on braking. With no fr RC improvements I would suggest #950 or a little more to limit travel.
5. A quality adj rear coilover - you'll need multiple springs (#200 & 250 FOR rr and street, no advice for drag) and bars (SB - 24 & 19mm, adj LCA, adj TA, & adj PHB) for the rear as you change between different driving events.
I've already said I'm likely to end up with viking shocks/coilovers back there eventually, but for now it's going to be Koni's and springs in the stock locations. I'm not at all worried about the rates for drag racing, in a straight line the rear springs only hold the back end up when you don't have enough torque applied for the anti-squat to hold the back of the car up, spring rate doesn't matter much. I'm hoping to just run the 25mm rear bar all the time and I would be THRILLED if this combination liked a rear spring in the 200-250 range, that would make things TONS easier than trying to keep things under 200 with traditional RC's and make for better street manners.
6. Wheel assemblies, brakes, and tires we haven't discussed. Could be drastic from drag to RR. I'm a foursquare guy, but Dean has suggested that fr 245 and rr 275 is perfectly fine - Burk's BBC has that. With 500rwhp, it makes some sense. For street it's fine (don't usually push that hard), but RR usually likes all 4. I'm on the fence and waiting.
#17
Re: Hybrid/All Purpose/Compramize Suspension Setup
Edit: I think I get it now, and I think that I have a problem here... I don't think I can move the tie rod down more than maybe a 1/8-1/4" from where it is now without hitting the rim. I have some 2.5" bolt on spacers in the garage, but I already think the 2" spacers space the rims out more than I'd like, and I'm not sure if the 2.5" spacers would sneak the tierods past the rim. I can't believe that everyone running extended ball joints is running 8" wide rims, and I'm sure I've seen 315/36-17's on the front of an AutoX car before, how are they getting them on there?
Actually, this is the biggest thing I'm worried about right now, like I already said, I'm not going to get the drop spindles on the car now, so if I'm buying extended ball joints do I go 1/2" or 1" (swapping them to something else when I put the drop spindles on is the least of my worries)? My current street tires are 265/40-17's on ZO6 17x9.5" +54mm offset wheels with a 2" bolt on spacer (stock brakes for now, so that puts it at virtually the same offset as the factory 16x8" fronts). I'm guessing that I'm better off geometry wise with the 1" extended ball joints, but does anyone know if they'll clear those wheels?
Ok, I'm missing something. I've read about how you might not be able to use the 2" drop spindles with 17x9.5" wheels, so I was wondering about "well where is the cutoff?" and decided "Hey, I can just crawl under the car and look to see how much clearance I have...
So I got under there and... well the I remembered that I've already looked at this, I have I have about 4" til that ball joint would contact the rim, what's the problem? I guess maybe the tie-rod might get close? I took some crappy pictures (it's not quite light out yet and everything is wet, I wasn't going to get a good pic:
Yup, thought I answered your questions in the thread, so I wasn't going to type twice.
I'm not comfortable with more than a 1" ext BJ. Not saying it can't be done safely, just think there are better ways (like drop spindles). Especially with heavier wheels like 17's or more. Just my opinion, though.
I'm not comfortable with more than a 1" ext BJ. Not saying it can't be done safely, just think there are better ways (like drop spindles). Especially with heavier wheels like 17's or more. Just my opinion, though.
So I got under there and... well the I remembered that I've already looked at this, I have I have about 4" til that ball joint would contact the rim, what's the problem? I guess maybe the tie-rod might get close? I took some crappy pictures (it's not quite light out yet and everything is wet, I wasn't going to get a good pic:
Last edited by 83 Crossfire TA; 07-26-2018 at 07:35 AM.
#18
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Re: Hybrid/All Purpose/Compromise Suspension Setup
I believe I already said that 8.5" wheel is the largest w/out hitting - 16-7" wheel. I read here somewhere that someone got creative with tie rod attachments and fit it inside the barrel of an 18" wheel with drop spindles.
Ext BJ's with 17 x 9.5" should be no problem - that is the best current option to date (drop spindles are not really an option per availability).
I dislike spacers on the front. Get better wheels. No one likes to hear that, similar to upgrading the rear end. Wheel assembly weight is critical to handling performance, and adding spacer weight while pushing out the hub mounting surface is well...I need a fart emoji. I can accept a small spacer on the rear to correct the offset, but not the front.
But you can see the difficulty in your hybrid/all purpose/compromise philosophy. We all make compromises, that's inherent. But the compromises should be known at the point of decision, hopefully. The most understandable compromise is one's wallet. Unsprung weight is sooo important - can't say it enough. Combine it with improved roll axis inclination and you have a great handling car - strength of the platform .
Here's another pic of my clearance.
Ext BJ's with 17 x 9.5" should be no problem - that is the best current option to date (drop spindles are not really an option per availability).
I dislike spacers on the front. Get better wheels. No one likes to hear that, similar to upgrading the rear end. Wheel assembly weight is critical to handling performance, and adding spacer weight while pushing out the hub mounting surface is well...I need a fart emoji. I can accept a small spacer on the rear to correct the offset, but not the front.
But you can see the difficulty in your hybrid/all purpose/compromise philosophy. We all make compromises, that's inherent. But the compromises should be known at the point of decision, hopefully. The most understandable compromise is one's wallet. Unsprung weight is sooo important - can't say it enough. Combine it with improved roll axis inclination and you have a great handling car - strength of the platform .
Here's another pic of my clearance.
#19
Re: Hybrid/All Purpose/Compromise Suspension Setup
I believe I already said that 8.5" wheel is the largest w/out hitting - 16-7" wheel. I read here somewhere that someone got creative with tie rod attachments and fit it inside the barrel of an 18" wheel with drop spindles.
Ext BJ's with 17 x 9.5" should be no problem - that is the best current option to date (drop spindles are not really an option per availability).
Ext BJ's with 17 x 9.5" should be no problem - that is the best current option to date (drop spindles are not really an option per availability).
17 x 9.5" should be no problem with what extended ball joints and offset?
My wheel+spacer combination should work out to about +4mm and I'm really close. It doesn't look bad looking at it but I got back under it again this morning and stuck my fingers in it and I have about 1/8" clearance. I figured that it looks like I'll have about the same problem with 1/2" and 1" extended BJ's (it looks like both will put the knuckle part of the tie rod against the wheel lip) so I got a set of 1" ball joints coming.
If it ends up looking close I may just try letting things clearance themselves. I wonder how much I can grind off the end of the tie rods without causing problems.
I dislike spacers on the front. Get better wheels. No one likes to hear that, similar to upgrading the rear end. Wheel assembly weight is critical to handling performance, and adding spacer weight while pushing out the hub mounting surface is well...I need a fart emoji. I can accept a small spacer on the rear to correct the offset, but not the front.
I'll be pretty annoyed if I end up having to run the 2.5" spacers, those will put my offset at about -8mm (again, vs a stock 0mm), which shouldn't be awful for bearing loads and scrub radius but I won't be happy with the look.
I'm not sure what better choices there are unless you go custom wheels. I mean you're running factory rims, at least the formula rims don't look out of place on your car. Honestly, my choice, if someone made a good 15" performance tire, would be to run widened firebird 15" rims (stock one in the middle) :
But you can see the difficulty in your hybrid/all purpose/compromise philosophy. We all make compromises, that's inherent. But the compromises should be known at the point of decision, hopefully. The most understandable compromise is one's wallet. Unsprung weight is sooo important - can't say it enough. Combine it with improved roll axis inclination and you have a great handling car - strength of the platform : imo :.
Here's another pic of my clearance.
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Re: Hybrid/All Purpose/Compromise Suspension Setup
I don't know of any company that currently offers drop spindles for our cars. Do you have a link? You're going to have to decide whether to use the drop spindles (8/8.5" wide wheels) or go with 9.5" wheels, OR 245 with drops, 275 without. The vast majority here does not have the choice of drops. You can re-read the first, "The Grip" thread https://www.thirdgen.org/forums/susp...2307-grip.html
I don't have any experience with positive offsets, but I'm guessing that +4mm is not too bad. Again, just don't like making scrub radius worse. I'm not against people using OEM from 4th Gen or Vette wheels for street and looks, but they are not a performance choice - not everyone has to make that choice, or even 18" or larger. There's room for everyone, but it's not a performance choice. Wide wheels and tires add weight and hurt scrub. Lightweight aftermarket can alleviate that (#35 w/tires is really good!). Paul's wheels are a really good choice at 17 x 9.5" with a weight of 21 lbs? or close to that. Now, AutoX is different as you don't have as many miles or speed involved. But RR needs good even wear (and even temps across tread) and street needs it for longevity. I can hit 140-50 twice a lap and a lap is 4 miles long! Bad scrub and wide tires w/ heavier wheel assemblies is not a recipe for good multiple lap times (10-12 laps per session, 3-4 sessions/day).
That's why your premise is almost impossible - too many variables and across different events/ or disciplines.
I have Spohn's bump steer kit.
You need several rear springs and bar combos - to me they just fall under the heading of "settings." You need them to find your own "on car" set-up. Can't really be done from the keyboard. You need options to see what fits your car and your own driving style. That's just to get one street set-up. Then, you need to find a good RR set-up, and a good drag set-up. I think multiple bars and springs is just NORMAL for anyone. The hybrid/ all purpose/ compromise would incorporate different rear bar/spring combos as well as "settings" (alignment changes, possibly slight ride height changes, shock settings, TA settings, PHB settings, LCA settings, brake pads, etc.). The constants would be wheels/tire selection, adj shocks, WJ's in fr and adj coilover in rear (both for ride height changes and for stiffness changes), front bar and spring choice, ext BJ and PHB bracket, etc = all the stuff we're talking about.
So to get an all-around handling car, you have to be able to change the "settings" for each different driving event. That's they way I understood your premise. Obviously, you have to skew the wheel/tire choice to street (90% of time and RR could be close) as drag would not be optimal.
1. Determine ride height (WJ's and rear coilovers),
2. adj roll axis inclination (RC changes via DropS?, ext BJ, PHBB axle side),
3. Quality adj struts and adj rear coilover (soft/stiff settings),
4. "Set" the front - things not easily changed (fr travel via spring rate, fr bar, best fr RC possible)
5. Find proper settings for each different driving event by experimenting (only thing taking off/on car is rear bars/springs),
6. Lightest and best control of wheel assemblies
I don't have any experience with positive offsets, but I'm guessing that +4mm is not too bad. Again, just don't like making scrub radius worse. I'm not against people using OEM from 4th Gen or Vette wheels for street and looks, but they are not a performance choice - not everyone has to make that choice, or even 18" or larger. There's room for everyone, but it's not a performance choice. Wide wheels and tires add weight and hurt scrub. Lightweight aftermarket can alleviate that (#35 w/tires is really good!). Paul's wheels are a really good choice at 17 x 9.5" with a weight of 21 lbs? or close to that. Now, AutoX is different as you don't have as many miles or speed involved. But RR needs good even wear (and even temps across tread) and street needs it for longevity. I can hit 140-50 twice a lap and a lap is 4 miles long! Bad scrub and wide tires w/ heavier wheel assemblies is not a recipe for good multiple lap times (10-12 laps per session, 3-4 sessions/day).
That's why your premise is almost impossible - too many variables and across different events/ or disciplines.
I have Spohn's bump steer kit.
You need several rear springs and bar combos - to me they just fall under the heading of "settings." You need them to find your own "on car" set-up. Can't really be done from the keyboard. You need options to see what fits your car and your own driving style. That's just to get one street set-up. Then, you need to find a good RR set-up, and a good drag set-up. I think multiple bars and springs is just NORMAL for anyone. The hybrid/ all purpose/ compromise would incorporate different rear bar/spring combos as well as "settings" (alignment changes, possibly slight ride height changes, shock settings, TA settings, PHB settings, LCA settings, brake pads, etc.). The constants would be wheels/tire selection, adj shocks, WJ's in fr and adj coilover in rear (both for ride height changes and for stiffness changes), front bar and spring choice, ext BJ and PHB bracket, etc = all the stuff we're talking about.
So to get an all-around handling car, you have to be able to change the "settings" for each different driving event. That's they way I understood your premise. Obviously, you have to skew the wheel/tire choice to street (90% of time and RR could be close) as drag would not be optimal.
1. Determine ride height (WJ's and rear coilovers),
2. adj roll axis inclination (RC changes via DropS?, ext BJ, PHBB axle side),
3. Quality adj struts and adj rear coilover (soft/stiff settings),
4. "Set" the front - things not easily changed (fr travel via spring rate, fr bar, best fr RC possible)
5. Find proper settings for each different driving event by experimenting (only thing taking off/on car is rear bars/springs),
6. Lightest and best control of wheel assemblies
#21
Re: Hybrid/All Purpose/Compromise Suspension Setup
I've been reading some old threads about this, including your original build thread (interestingly, nothing about extended ball joints in there), and realized that we've talked about some of this like 8 years ago...
I have these sitting in the garage that I need to finish...
and now I'm wondering about either breaking the tacks on the steering arm part or possibly putting a harder bend in it towards the tie rod seat to move it inward about 1/2" and clear more wheels (I'll know how much I need exactly after I try the extended ball joints). I haven't decided if this will mess anything up besides bump steer yet...
I'm pretty sure I've started reading that a few times and never finished, something about it makes it hard to read... will try again...
As long as you keep the offset the same scrub doesn't change. Last I checked I know you can do that with 17x9.5" rims (right now I technically have better scrub than the stock 16" wheels, but 4mm), 16x9" rims (as long as the wheel lips are fairly thin, the tie rod exactly lines up with it stock), and I'm not sure 15's and 18's (and don't care about anything outside that)
Yea, I fully realize that I can't have everything, but I do believe that what I've been calling a 95% handling (meaning getting 95% of the available handling out of it with the right tires on it, if I was capable of driving that fast, and by that I also don't mean 95% of the possible work/tuning, because I fully understand that to get that last 5% would probably take more work than getting the previous 95%, heck with these cars you could probably get to 75-80% by just getting all the stock stuff in good shape), 90% Drag and 85% street.... I believe that we have a few cars like that on here already, at least as close as their owners bother to get to that (Justin's IROC comes to mind, though last I saw he's gone and skewed that with the current TT big block swap).
There are a few things that I'd like to make "adjustable" rather than "swap" to go from one to the other. A quick disconnect for the front sway bar would be nice, adjustable rear sway bar, adjustable shocks (which is why I keep saying that I'll end up upgrading) and a few other things. Swapping tires is a given. Heck, I have a tire rack in both the garage and basement, and I still have a stack of them under the deck... if you race anything in mutiple disciplines you're going to have LOTS of tires. Nitto 555r Drag radials used to be a pretty good compromise- they have stiffer sidewalls than most DR's, a really good tread compound that could be made to work on the street (even in the rain), dragstrip, and some larger cars would use them on all 4 at AutoX...
Secondly, you seem to think that drag is MUCH harder to setup for than it really is. With these cars you can put decent tires on them and get 90% of the way there, no matter what the suspension is setup for. If it's lowered a lot relo brackets help but aren't as necessary as people say. I usually start with an aftermarket PHR (the stock one will flex on a hard 1-2 shift causing the car to jump sideways). Past that, unless you build a very violent drivetrain, you can get more out of being a good driver than everything else you can do to the suspension.
I've asked this before and haven't seen a real answer- is there a reason not to do rear WJ? I know that somewhere (I've done a lot of reading, don't remember where) someone said something about how thin the spring pockets are, but they have to be re-enforced for coil overs also, so I don't see that as a reason. It seems like the typical GC setup is overly complicated and adds unnecessary unsprung weight.
this is what I think is the biggest deficiency with the Koni's, you have to remove them to adjust them.
I hate to say it, but expecially if it's still a street car, style comes in with wheels.
I don't know of any company that currently offers drop spindles for our cars. Do you have a link? You're going to have to decide whether to use the drop spindles (8/8.5" wide wheels) or go with 9.5" wheels, OR 245 with drops, 275 without. The vast majority here does not have the choice of drops.
and now I'm wondering about either breaking the tacks on the steering arm part or possibly putting a harder bend in it towards the tie rod seat to move it inward about 1/2" and clear more wheels (I'll know how much I need exactly after I try the extended ball joints). I haven't decided if this will mess anything up besides bump steer yet...
You can re-read the first, "The Grip" thread https://www.thirdgen.org/forums/susp...2307-grip.html
I don't have any experience with positive offsets, but I'm guessing that +4mm is not too bad. Again, just don't like making scrub radius worse. I'm not against people using OEM from 4th Gen or Vette wheels for street and looks, but they are not a performance choice - not everyone has to make that choice, or even 18" or larger. There's room for everyone, but it's not a performance choice. Wide wheels and tires add weight and hurt scrub. Lightweight aftermarket can alleviate that (#35 w/tires is really good!). Paul's wheels are a really good choice at 17 x 9.5" with a weight of 21 lbs? or close to that. Now, AutoX is different as you don't have as many miles or speed involved. But RR needs good even wear (and even temps across tread) and street needs it for longevity. I can hit 140-50 twice a lap and a lap is 4 miles long! Bad scrub and wide tires w/ heavier wheel assemblies is not a recipe for good multiple lap times (10-12 laps per session, 3-4 sessions/day).
That's why your premise is almost impossible - too many variables and across different events/ or disciplines.
So to get an all-around handling car, you have to be able to change the "settings" for each different driving event. That's they way I understood your premise. Obviously, you have to skew the wheel/tire choice to street (90% of time and RR could be close) as drag would not be optimal.
Secondly, you seem to think that drag is MUCH harder to setup for than it really is. With these cars you can put decent tires on them and get 90% of the way there, no matter what the suspension is setup for. If it's lowered a lot relo brackets help but aren't as necessary as people say. I usually start with an aftermarket PHR (the stock one will flex on a hard 1-2 shift causing the car to jump sideways). Past that, unless you build a very violent drivetrain, you can get more out of being a good driver than everything else you can do to the suspension.
1. Determine ride height (WJ's and rear coilovers),
2. adj roll axis inclination (RC changes via DropS?, ext BJ, PHBB axle side),
3. Quality adj struts and adj rear coilover (soft/stiff settings),
3. Quality adj struts and adj rear coilover (soft/stiff settings),
4. "Set" the front - things not easily changed (fr travel via spring rate, fr bar, best fr RC possible)
5. Find proper settings for each different driving event by experimenting (only thing taking off/on car is rear bars/springs),
6. Lightest and best control of wheel assemblies
5. Find proper settings for each different driving event by experimenting (only thing taking off/on car is rear bars/springs),
6. Lightest and best control of wheel assemblies
#24
Re: Hybrid/All Purpose/Compromise Suspension Setup
- How did you drill the hole through the frame rail that close to perpendicular to what the threaded plates ended up at so the jack screws were pretty well centered in the holes?
- Any disadvantages to going through the frame rail with the WJ?
- Do you think I can get this thing in that space? That sleave is currently 1.625" OD so it would need pretty close to a 2" hole and I'm not sure if that would hit the side wall of the frame rail. I could turn it down to 1.5" or maybe a little smaller and that would make a 1.75" hole, maybe smaller work. You have less thread and no grease fitting, do you see a point in a grease fitting (I'm guessing I'm probably loosing that no matter what). Your screws are 6" (but in the description it says 5.5", huh?)- any point in making them longer or shorter (I have some 8" ones now, but I could cut them down)?
- Any disadvantages to going through the frame rail with the WJ?
- Do you think I can get this thing in that space? That sleave is currently 1.625" OD so it would need pretty close to a 2" hole and I'm not sure if that would hit the side wall of the frame rail. I could turn it down to 1.5" or maybe a little smaller and that would make a 1.75" hole, maybe smaller work. You have less thread and no grease fitting, do you see a point in a grease fitting (I'm guessing I'm probably loosing that no matter what). Your screws are 6" (but in the description it says 5.5", huh?)- any point in making them longer or shorter (I have some 8" ones now, but I could cut them down)?
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Re: Hybrid/All Purpose/Compromise Suspension Setup
Who makes that Drop Spindle? Weld strength is critical. They look beefy enough, but that tack weld is suspicious. There was discussion about moving the steering arm attachment, but it certainly alters geometry. You have to search to find the thread (Phil, can't remember user name). I don't think this is worth messing with to gain 275 from 245 if you read The Grip, again. Yeah, I re-read, too, and forgot about the rear RC migrating with a progressive rate spring in rear. Lots to digest.
I think rear WJ's are unnecessary. The best shock tech is showing up in coilovers, plus it gives you ride height alter-ability. You have to choose the shock properly, because even a coilover only has approximately 3/4" adjustment before you are operating outside the range of the shock.
Yes on wheels, I think of them as jewelry. Very important to the overall presentation of the car. Performance comes first, though. I lust after Forgeline GW3 w/competition cap.
I think rear WJ's are unnecessary. The best shock tech is showing up in coilovers, plus it gives you ride height alter-ability. You have to choose the shock properly, because even a coilover only has approximately 3/4" adjustment before you are operating outside the range of the shock.
Yes on wheels, I think of them as jewelry. Very important to the overall presentation of the car. Performance comes first, though. I lust after Forgeline GW3 w/competition cap.
#26
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Re: Hybrid/All Purpose/Compromise Suspension Setup
- How did you drill the hole through the frame rail that close to perpendicular to what the threaded plates ended up at so the jack screws were pretty well centered in the holes?
- Any disadvantages to going through the frame rail with the WJ?
- Do you think I can get this thing in that space? That sleave is currently 1.625" OD so it would need pretty close to a 2" hole and I'm not sure if that would hit the side wall of the frame rail. I could turn it down to 1.5" or maybe a little smaller and that would make a 1.75" hole, maybe smaller work. You have less thread and no grease fitting, do you see a point in a grease fitting (I'm guessing I'm probably loosing that no matter what). Your screws are 6" (but in the description it says 5.5", huh?)- any point in making them longer or shorter (I have some 8" ones now, but I could cut them down)?
- Any disadvantages to going through the frame rail with the WJ?
- Do you think I can get this thing in that space? That sleave is currently 1.625" OD so it would need pretty close to a 2" hole and I'm not sure if that would hit the side wall of the frame rail. I could turn it down to 1.5" or maybe a little smaller and that would make a 1.75" hole, maybe smaller work. You have less thread and no grease fitting, do you see a point in a grease fitting (I'm guessing I'm probably loosing that no matter what). Your screws are 6" (but in the description it says 5.5", huh?)- any point in making them longer or shorter (I have some 8" ones now, but I could cut them down)?
Here's a pic of all the parts purchased. Drop Spindles were sent back in for the Road Race upgrade (even though my invoice says, RR so you and Tibo are not the only ones to go through some frustration - but they took care of me at additional expense to me).
Other pic shows the spring cup of the weight jack coming down from inside the k-member. I didn't have or use a grease fitting. The threads are coarse and I don't monkey with them a lot (some). I can remove the spring with my fingers once the WJ bolt is screwed all the way up. Easy to put back in, too. Been debating whether or not I could switch to a 11" spring, but I would definitely need a spring compressor each time. Every thing is working fine, so KISS principle.
#27
Re: Hybrid/All Purpose/Compromise Suspension Setup
I drilled a center hole as you can see, that enbabled me to see where it was going to come through the frame rail. I didn't want to hit the brake lines or anything else. Then used the hole saw to cut the hole. Then I purchased a long bolt with same thread to loosely put a nut on the frame rail side and on the bottom of the plate that I was going to weld (to keep the plate secure). It worked perfectly. If it doesn't, you can always elongate the hole with a file if needed.
That sleave is currently 1.625" OD so it would need pretty close to a 2" hole in the bottom of the frame rail and I'm not sure if that would hit the side wall of the frame rail. I could turn it down to 1.5" or maybe a little smaller and that would make a 1.75" hole, maybe smaller work. You have less thread and no grease fitting, do you see a point in a grease fitting (I'm guessing I'm probably loosing that no matter what)?
This is the current UMI spring pocket. I would make the top thicker and it would lose the spring locating ring, then the WJ nut/sleave that I was holding in the previous picture would be welded to it sticking out on the side where my hand is and it would stick through a hole in the bottom of the frame rail... if there's room for a hole that big which is what I'm asking you because you've been in there, cut a hole (how big was it?) and am wondering how much bigger the hole could be.
#28
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Re: Hybrid/All Purpose/Compromise Suspension Setup
I don't think you can get that sleeve to fit w/out cutting a big hole. I used a 1" hole saw pictured in the upper left of the parts pic. You can go bigger, but you want the smallest that will work, and you don't want to be too close to the edges of the rail. Afterwards, you can but a rubber boot over it to cover everything - see pic.
Berk welded his plates to a tubular k-member but his pics are gone. I remember using some kind of spacer to make sure the plates were not touching the rail (of course, I wouldn't weld to the rail but I wanted some little space between. I don't see the point of the grease fitting with such coarse threads. What brand/style of WJ are you using. Maybe a full pic of it will help.
The bracing on the original street version of the DS was hitting the end link. If you look at the road race version, the arm is so beefy, it doesn't need the bracing, so no worries at all with hitting the end link. It only hit the end link because Spohn moved the attachment point on their tubular a-arms - you can't have an attachment point straight through the center line of the tube, so they made the attachment on the side of the tube which moved it from the stock a-arm as they were centered on a stamped a-arm. Kind of like: you don't know till you need to know, then it's too late. But the RR version has no problems.
Berk welded his plates to a tubular k-member but his pics are gone. I remember using some kind of spacer to make sure the plates were not touching the rail (of course, I wouldn't weld to the rail but I wanted some little space between. I don't see the point of the grease fitting with such coarse threads. What brand/style of WJ are you using. Maybe a full pic of it will help.
The bracing on the original street version of the DS was hitting the end link. If you look at the road race version, the arm is so beefy, it doesn't need the bracing, so no worries at all with hitting the end link. It only hit the end link because Spohn moved the attachment point on their tubular a-arms - you can't have an attachment point straight through the center line of the tube, so they made the attachment on the side of the tube which moved it from the stock a-arm as they were centered on a stamped a-arm. Kind of like: you don't know till you need to know, then it's too late. But the RR version has no problems.
#29
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Re: Hybrid/All Purpose/Compromise Suspension Setup
I used the stock center hole to drill my centering hole, then cut out the spring cup.
The first side I did, I cut too much of the k-member cup out, and had to do some bridge welding.
The other side, I left some of the curved rind, increment cut all around, hammered flat, then welded all around the cuts - much better method and better weld penetration.
The first side I did, I cut too much of the k-member cup out, and had to do some bridge welding.
The other side, I left some of the curved rind, increment cut all around, hammered flat, then welded all around the cuts - much better method and better weld penetration.
#30
Re: Hybrid/All Purpose/Compromise Suspension Setup
I don't think you can get that sleeve to fit w/out cutting a big hole. I used a 1" hole saw pictured in the upper left of the parts pic. You can go bigger, but you want the smallest that will work, and you don't want to be too close to the edges of the rail. Afterwards, you can but a rubber boot over it to cover everything - see pic.
I agree with not wanting to be too close, I definitely don't want to touch the side or the corners of the frame rail box. I could get away with it if I plated it on the outside, which can be done if the engine was out, but not an option here.
These have an OD of 1.625" which would require a huge hole, but I could cut them down so they'll fit in a 1.75" hole (I don't know if I could get them small enough to use a 1.5" hole, and I don't know what size hole saws I can find if any in between 1.5 and 1.75... Short like the boss on the threaded plate you used makes me nervous. I'm guessing that the boss on yours is about 1/4" on a 1/4" plate, making it about 1/2" threaded area, at 8tpi that's 4 threads, about the absolute minimum that you can get away with for a full strength of that thread in steel. I also figure that up into the frame rail gives you more room than down into the bucket for the longest possible adjustment range.
If I do the K-member, I'm thinking of talking to a friend and trying to do it at his work after hours on a lift, since this will suck and take more time than I'm willing on the ground in the driveway (the big problem is the driveway is decently steep and I can't currently get a car in my garage), so if I do that I want to have all my fabrication done before bringing it over and make this a 1 night project.
Berk welded his plates to a tubular k-member but his pics are gone.
I remember using some kind of spacer to make sure the plates were not touching the rail (of course, I wouldn't weld to the rail but I wanted some little space between. I don't see the point of the grease fitting with such coarse threads.
Do you remember how much space there was between the top of the K and the bottom of the frame rail?
What band /style of WJ are you using. Maybe a full pic of it will help.
The bracing on the original street version of the DS was hitting the end link. If you look at the road race version, the arm is so beefy, it doesn't need the bracing, so no worries at all with hitting the end link. It only hit the end link because Spohn moved the attachment point on their tubular a-arms - you can't have an attachment point straight through the center line of the tube, so they made the attachment on the side of the tube which moved it from the stock a-arm as they were centered on a stamped a-arm. Kind of like: you don't know till you need to know, then it's too late. But the RR version has no problems.
I used the stock center hole to drill my centering hole, then cut out the spring cup.
The first side I did, I cut too much of the k-member cup out, and had to do some bridge welding.
The other side, I left some of the curved rind, increment cut all around, hammered flat, then welded all around the cuts - much better method and better weld penetration.
The first side I did, I cut too much of the k-member cup out, and had to do some bridge welding.
The other side, I left some of the curved rind, increment cut all around, hammered flat, then welded all around the cuts - much better method and better weld penetration.
Last edited by 83 Crossfire TA; 07-28-2018 at 03:47 PM.
#31
Re: Hybrid/All Purpose/Compromise Suspension Setup
I just noticed these Koni (they used to call them something like SiLastO) shaft mounted bump stops... what did you use them for?
I had to cut my frame mounts off the back of my car to clear the assorted large rear wheels/tires and have a set of those to put on the rear shocks, but I haven't and haven't figured out how to get them over the shafts either...
While I'm thinking about it, I don't see any in your pics and with the reinforcement plates you put on the bottom of your strut towers I'm guessing you don't have room... are you running any kind of shields/boots on your front struts?
#32
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Re: Hybrid/All Purpose/Compromise Suspension Setup
since you are using the UMI k member have you considered their weight jack that works with their spring support and avoids needing to drill through the frame rail? (sorry if i missed an explanation above as i just scanned through this quickly so far)
http://umiperformance.com/catalog/in...oducts_id=1113
i have put this in one of my projects but ran out of time to get it on the road this summer, but so far it seems quite well thought out and mounted up good. i have an 85 iroc with the UMI components with the DSE weight jack, i will likely be swapping that out with the UMI one if my experience in this new project is good. there are a couple of issues in my opinion with the DSE one but it does work ok for now
see post #9 in the thread below for the installation of the UMI weight jacks with their k member and a arms
https://www.thirdgen.org/forums/engi...ort-coupe.html
http://umiperformance.com/catalog/in...oducts_id=1113
i have put this in one of my projects but ran out of time to get it on the road this summer, but so far it seems quite well thought out and mounted up good. i have an 85 iroc with the UMI components with the DSE weight jack, i will likely be swapping that out with the UMI one if my experience in this new project is good. there are a couple of issues in my opinion with the DSE one but it does work ok for now
see post #9 in the thread below for the installation of the UMI weight jacks with their k member and a arms
https://www.thirdgen.org/forums/engi...ort-coupe.html
#33
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Car: '89 Formula
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Re: Hybrid/All Purpose/Compromise Suspension Setup
I just measured the hole saw = 1 1/4", then I did use a round file to clean up the edges.
My local hardware store has an insane amount of stock.
There is not much between the k-member and the rail - 1/4" or less. Cutting the hole in the rail was way too easy. The k-member much more difficult. I used a cutting wheel on my back under the car. Same with welding up in the cup. If one knew they were going to LS swap, you could measure and mark (pilot hole), then take it out and do a much more professional job. I did weld a little from the top with the empty engine bay, and clean up what was visible.
Yes, I used Spohn's reinforcement plates (for coilovers) just to give added weight distribution at the strut tower - I think that is a good idea. I re-used the stock shields - it was no easy feat to get them to fit and work properly with the Spohn strut mounts. I remember fighting those little things for quite a while. The washer that goes over the shaft is cupped and ridged. I had to flatten so they wouldn't interfere with the bearings in the strut mount. I did shave the bottom of the bump stops a little. Here's the only pic I have showing the shields. I had ordered the FSL narrow 6pot,( the rotors didn't fit, didn't like them, and settled on 2 pc curved vane slotted), and some confusion over the alum hubs (another aftermarket sale that had to be worked out). My lightweight front brakes/wheel assembly was not cheap. Another reason (they add up) why I don't need a larger spring rate.
Bump stop: https://www.spohn.net/shop/1982-1992...tops-Pair.html
My local hardware store has an insane amount of stock.
There is not much between the k-member and the rail - 1/4" or less. Cutting the hole in the rail was way too easy. The k-member much more difficult. I used a cutting wheel on my back under the car. Same with welding up in the cup. If one knew they were going to LS swap, you could measure and mark (pilot hole), then take it out and do a much more professional job. I did weld a little from the top with the empty engine bay, and clean up what was visible.
Yes, I used Spohn's reinforcement plates (for coilovers) just to give added weight distribution at the strut tower - I think that is a good idea. I re-used the stock shields - it was no easy feat to get them to fit and work properly with the Spohn strut mounts. I remember fighting those little things for quite a while. The washer that goes over the shaft is cupped and ridged. I had to flatten so they wouldn't interfere with the bearings in the strut mount. I did shave the bottom of the bump stops a little. Here's the only pic I have showing the shields. I had ordered the FSL narrow 6pot,( the rotors didn't fit, didn't like them, and settled on 2 pc curved vane slotted), and some confusion over the alum hubs (another aftermarket sale that had to be worked out). My lightweight front brakes/wheel assembly was not cheap. Another reason (they add up) why I don't need a larger spring rate.
Bump stop: https://www.spohn.net/shop/1982-1992...tops-Pair.html
#34
Re: Hybrid/All Purpose/Compromise Suspension Setup
since you are using the UMI k member have you considered their weight jack that works with their spring support and avoids needing to drill through the frame rail? (sorry if i missed an explanation above as i just scanned through this quickly so far)
http://umiperformance.com/catalog/in...oducts_id=1113
i have put this in one of my projects but ran out of time to get it on the road this summer, but so far it seems quite well thought out and mounted up good. i have an 85 iroc with the UMI components with the DSE weight jack, i will likely be swapping that out with the UMI one if my experience in this new project is good. there are a couple of issues in my opinion with the DSE one but it does work ok for now
see post #9 in the thread below for the installation of the UMI weight jacks with their k member and a arms
https://www.thirdgen.org/forums/engi...ort-coupe.html
http://umiperformance.com/catalog/in...oducts_id=1113
i have put this in one of my projects but ran out of time to get it on the road this summer, but so far it seems quite well thought out and mounted up good. i have an 85 iroc with the UMI components with the DSE weight jack, i will likely be swapping that out with the UMI one if my experience in this new project is good. there are a couple of issues in my opinion with the DSE one but it does work ok for now
see post #9 in the thread below for the installation of the UMI weight jacks with their k member and a arms
https://www.thirdgen.org/forums/engi...ort-coupe.html
Honestly, if I can have anything that adjusts without getting under the car I'll do it... I'm not excited about getting under a car that I already can't get under, so you have to get it up of the ground, adjust and then put it back down to see how it looks... I know it's really not _that_ bad, but if you're going to do it...
#35
Re: Hybrid/All Purpose/Compromise Suspension Setup
I need to find a good pic of the UMI RR K memeber installed to see how close that stock spring pocket comes to the frame rail (to see if I can weld above or below, I'm obviously looking for every last fraction of an inch here WRT to spring height).
My local hardware store has an insane amount of stock.
There is not much between the k-member and the rail - 1/4" or less. Cutting the hole in the rail was way too easy. The k-member much more difficult. I used a cutting wheel on my back under the car. Same with welding up in the cup. If one knew they were going to LS swap, you could measure and mark (pilot hole), then take it out and do a much more professional job. I did weld a little from the top with the empty engine bay, and clean up what was visible.
There is not much between the k-member and the rail - 1/4" or less. Cutting the hole in the rail was way too easy. The k-member much more difficult. I used a cutting wheel on my back under the car. Same with welding up in the cup. If one knew they were going to LS swap, you could measure and mark (pilot hole), then take it out and do a much more professional job. I did weld a little from the top with the empty engine bay, and clean up what was visible.
Yes, I used Spohn's reinforcement plates (for coilovers) just to give added weight distribution at the strut tower - I think that is a good idea. I re-used the stock shields - it was no easy feat to get them to fit and work properly with the Spohn strut mounts. I remember fighting those little things for quite a while. The washer that goes over the shaft is cupped and ridged. I had to flatten so they wouldn't interfere with the bearings in the strut mount. I did shave the bottom of the bump stops a little. Here's the only pic I have showing the shields. I had ordered the FSL narrow 6pot,( the rotors didn't fit, didn't like them, and settled on 2 pc curved vane slotted), and some confusion over the alum hubs (another aftermarket sale that had to be worked out). My lightweight front brakes/wheel assembly was not cheap. Another reason (they add up) why I don't need a larger spring rate.
Bump stop: https://www.spohn.net/shop/1982-1992...tops-Pair.html
Bump stop: https://www.spohn.net/shop/1982-1992...tops-Pair.html
and you got the stock strut shields to fit and clear with decent caster (I've seen more than one car that you couldn't get anywhere near 5* caster with the strut shields on), and I don't think caster/camber plates help that at all...
#37
COTM Editor
Re: Hybrid/All Purpose/Compromise Suspension Setup
https://www.thirdgen.org/forums/ltx-...ne-swap-8.html
i happen to have this iroc on the lift and went and took a picture and a quick measurement for you ... it is about 0.75" gap between the top of the umi spring pocket and the frame
i have used the umi rr k member in several swaps which have swap threads and have some other pics of the k member in them
#38
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Re: Hybrid/All Purpose/Compromise Suspension Setup
It looks like it belongs.
Stock LS2 (JY pull w/32k on it) and I kept the DBW! That's why I needed the Mark Williams 12 bolt. Again, the alum block took a few pounds off the front to help get me to #850 front spring rate. Lots of little things add up.
Yeah, I think you could do 1 3/4". If needed, you can file away a little just to make sure. But I see no reason for the fitting. Nothing will disturb the threads just above the plate (inside the rail), and very little will get above the spring cup to disturb threads below the plate. Plus, coarse threads will help. I would ditch it. If you absolutely feel you must, put it below the plate and no need for a bigger hole. I have no problems, whatsoever. I don't even jack the car off the ground to turn the bolt. I jack a little to take most of the weight off, but not all. Like you said, I don't have to get under.
Alan - 0.75" is excellent. Plenty of room. If I ever were to consider an aftermarket k-member, the UMI RR is the only one I would.
Stock LS2 (JY pull w/32k on it) and I kept the DBW! That's why I needed the Mark Williams 12 bolt. Again, the alum block took a few pounds off the front to help get me to #850 front spring rate. Lots of little things add up.
Yeah, I think you could do 1 3/4". If needed, you can file away a little just to make sure. But I see no reason for the fitting. Nothing will disturb the threads just above the plate (inside the rail), and very little will get above the spring cup to disturb threads below the plate. Plus, coarse threads will help. I would ditch it. If you absolutely feel you must, put it below the plate and no need for a bigger hole. I have no problems, whatsoever. I don't even jack the car off the ground to turn the bolt. I jack a little to take most of the weight off, but not all. Like you said, I don't have to get under.
Alan - 0.75" is excellent. Plenty of room. If I ever were to consider an aftermarket k-member, the UMI RR is the only one I would.
#39
Re: Hybrid/All Purpose/Compromise Suspension Setup
you can see some photos of umi k member road race in post 394 in my 85 iroc LS swap thread
https://www.thirdgen.org/forums/ltx-...ne-swap-8.html
i happen to have this iroc on the lift and went and took a picture and a quick measurement for you ... it is about 0.75" gap between the top of the umi spring pocket and the frame
i have used the umi rr k member in several swaps which have swap threads and have some other pics of the k member in them
https://www.thirdgen.org/forums/ltx-...ne-swap-8.html
i happen to have this iroc on the lift and went and took a picture and a quick measurement for you ... it is about 0.75" gap between the top of the umi spring pocket and the frame
i have used the umi rr k member in several swaps which have swap threads and have some other pics of the k member in them
I'm positive that I'll have more questions for you once I get my thoughts together, but first let's get everyone on the same page... I am wondering where in PA you're located since parts of PA are only an hour from where I'm at in MD...
It really does, even to someone that isn't really a fan of LS swaps (I'm probably the last one).
Yeah, I think you could do 1 3/4". If needed, you can file away a little just to make sure. But I see no reason for the fitting. Nothing will disturb the threads just above the plate (inside the rail), and very little will get above the spring cup to disturb threads below the plate. Plus, coarse threads will help. I would ditch it. If you absolutely feel you must, put it below the plate and no need for a bigger hole. I have no problems, whatsoever. I don't even jack the car off the ground to turn the bolt. I jack a little to take most of the weight off, but not all. Like you said, I don't have to get under.
Alan - 0.75" is excellent. Plenty of room. If I ever were to consider an aftermarket k-member, the UMI RR is the only one I would.
Alan - 0.75" is excellent. Plenty of room. If I ever were to consider an aftermarket k-member, the UMI RR is the only one I would.
Reading your reply, If the fitting you're talking about is the grease zerk... I gave up on that when it first came up, and WRT to disturbing the threads, I'm not sure what you mean besides maybe damage them or wipe the grease off of them? I don't know what coarse threads will help with.
As far as what I'm thinking right now:
- I'm thinking of cutting off the existing spring locator from the spring pocket (red)
- Turning down the nut/sleave to make it easier to fit in a 1.75" hole (magenta)
- Making a plate that the nut passes through and gets welded to, and then gets welded to the top of the original spring bucket (blue)
- The green is the section that will pass through a 1.75" hole in the bottom of the frame rail and a 1.25" hole in the top and be inside the frame rail
I'm guessing that I'm going to probably need to get shorter bolts or shorten those if yours are 6", these are 8".
The idea is that like this I'll be able to back the weight jack spring cup all the way up till it's just about flat with the top of the spring pocket, giving me as much room for the longest free length springs that I can fit in there.
Last edited by 83 Crossfire TA; 07-29-2018 at 05:35 AM.
#40
Re: Hybrid/All Purpose/Compromise Suspension Setup
Why is it never easy?
#41
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Re: Hybrid/All Purpose/Compromise Suspension Setup
As far as what I'm thinking right now:
.
- I'm thinking of cutting off the existing spring locator from the spring pocket (red)
- Turning down the nut/sleave to make it easier to fit in a 1.75" hole (magenta)
- Making a plate that the nut passes through and gets welded to, and then gets welded to the top of the original spring bucket (blue)
- The green is the section that will pass through a 1.75" hole in the bottom of the frame rail and a 1.25" hole in the top and be inside the frame rail
.
You should have a plate that the bolt threads into - not a nut: https://www.speedwaymotors.com/WEIGH...LATE,6509.html
The plate is flat on upper side nearest frame rail, and protruding nut on bottom towards the spring cup of the weight jack. No need for big holes.
Berk welded the plate on the k-member cup (red cross). If you're looking to get tallest spring, you could cut or grind the k-member cup down, then weld the plate to that (flat side up). Start with a 9.5" x 5.5" spring. The only thing that protrudes above the k-member is the bolt (blue line or above it).
#42
COTM Editor
Re: Hybrid/All Purpose/Compromise Suspension Setup
I tried to take another photo to illustrate the angle, but yes you are right the angle of the UMI spring pocket is angled outwards compared to the frame rail
Also i took another pic from one of my other 3rd gens from the top to illustrate the relative position of the spring pocket... i think you likely need to make your own spring pocket or significantly modify the UMI one if you are going to attempt to have the jack bolt come through the frame rail as you can see the location and angle of the UMI one presently is not lining up for doing this it would appear
Also i took another pic from one of my other 3rd gens from the top to illustrate the relative position of the spring pocket... i think you likely need to make your own spring pocket or significantly modify the UMI one if you are going to attempt to have the jack bolt come through the frame rail as you can see the location and angle of the UMI one presently is not lining up for doing this it would appear
#43
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Re: Hybrid/All Purpose/Compromise Suspension Setup
It sure is angled. When Berk did his in '10 , he used Spohn's.
The center point of the upper spring cup does not appear to be far off or very minimal. But that angle could put the bolt too close to the edge of the boxed rail, yup.
I wonder if you could shim the attachment bolts that attach the springs perches to the k-member to get back the correct angle.
The center point of the upper spring cup does not appear to be far off or very minimal. But that angle could put the bolt too close to the edge of the boxed rail, yup.
I wonder if you could shim the attachment bolts that attach the springs perches to the k-member to get back the correct angle.
#45
Re: Hybrid/All Purpose/Compromise Suspension Setup
I tried to take another photo to illustrate the angle, but yes you are right the angle of the UMI spring pocket is angled outwards compared to the frame rail
Also i took another pic from one of my other 3rd gens from the top to illustrate the relative position of the spring pocket... i think you likely need to make your own spring pocket or significantly modify the UMI one if you are going to attempt to have the jack bolt come through the frame rail as you can see the location and angle of the UMI one presently is not lining up for doing this it would appear
Also i took another pic from one of my other 3rd gens from the top to illustrate the relative position of the spring pocket... i think you likely need to make your own spring pocket or significantly modify the UMI one if you are going to attempt to have the jack bolt come through the frame rail as you can see the location and angle of the UMI one presently is not lining up for doing this it would appear
Yea, that pretty much confirms what I thought I was seeing in your pics. It looks like if I mounted the WJ screw in the center of the UMI pocket perpendicular to the surface it would come out about here:
Now why the heck did UMI change that from stock?
#46
Re: Hybrid/All Purpose/Compromise Suspension Setup
So playing what if here (and Alan, you're the only one that has seen this thing assembled so far and I'm working off your "3/4" gap" which you know where it's 3/4", but I'll welcome input from anyone):
- If I got rid of that 11* angle and made it as tall as the tall side of the bracket arms (the LH side in this picture, but the bracket is being held upside down) would it still clear the bottom of the frame rails and by about how much?
- If I made the strap width (yellow arrow in the second picture) 2" or even 2.25" (it is now 1.75") would it still clear everything? I don't know how close it is to A (bump stop pad?) and I don't know what B is and if it would get in the way.
#47
Re: Hybrid/All Purpose/Compromise Suspension Setup
FWIW, I went with a set of calipers, a tape measure, and a calculator into my stockpile of springs in the garage and I think I found the perfect springs if I can figure out the weight jacks. I found a set of Eibach Pro front springs (710# advertised rate) which have a free height of 12.75". Doing some quick math (double checked it by putting the stock numbers in and got 709#), if I cut one coil off I have a 858# spring with a free height of 11.5", which should sit 2" lower - about 40% of whatever my WJ assemblies height ends up than the pro kit height, so it should be about as tall a free hight spring as I can get in there, about 860# rate and adjustable from about 1.5" lower than I want to go to at least stock height.
#48
Re: Hybrid/All Purpose/Compromise Suspension Setup
So playing what if here (and Alan, you're the only one that has seen this thing assembled so far and I'm working off your "3/4" gap" which you know where it's 3/4", but I'll welcome input from anyone):
- If I got rid of that 11* angle and made it as tall as the tall side of the bracket arms (the LH side in this picture, but the bracket is being held upside down) would it still clear the bottom of the frame rails and by about how much?
- If I made the strap width (yellow arrow in the second picture) 2" or even 2.25" (it is now 1.75") would it still clear everything? I don't know how close it is to A (bump stop pad?) and I don't know what B is and if it would get in the way.
Any thoughts on these guys?
Assuming those 2 conditions work, then I'm thinking something like this might be the solution (modeled 2" wide, and again, the zerk would probably be removed but I modeled it with it just to see where it would end up the way it's currently drilled):
#50
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Re: Hybrid/All Purpose/Compromise Suspension Setup
With the stock k-member still bolted up - I would drill a small pilot hole in the rail like I did. That will give you a reference of stock center, once you remove the stock k-member.
Just how you re-adjust the angle put into the UMI spring cup bracket is up to you. Just for knowledge gathering before doing, I would take some thick washers, grind an angle into them, put them between the bracket and k-member, and just see how much re-adjustment can be accomplished. If it gets you there, you could tack weld to bracket for final install. If you don't like it, you haven't wasted much while learning. Once you alter the bracket, there's no going back or have to re-purchase that part.
The bolt through the rail does not have to be perfectly perpendicular - aesthetics only. Casual eyeball is fine.
You still need a plate welded to the spring cup, NOT the frame rail (very weak). Plate will have enough spring force to ensure no vertical movement, but the lateral/side-to-side movement is critical to prevent. That's different if you're wanting to weld a plate to the topmost portion of the spring cup (your blue line). I would suggest cutting down the vertical length of the spring cup (portion with the red X) and weld to the bottom of the remaining cup. That is always the way I've seen it done, but there's always a first.
You seem married to that nut (no, not your wife - nut w/zirk fitting). I see no benefit, and it's causing you design problem considerations. DSE doesn't use them, and their threads are much, much closer to the elements in the bottom of the a-arm.
Your spring ideas seem fine.