autocross suspension setup suggestions?
03-02-2012, 02:50 PM
#1
Member
Thread Starter
Join Date: Aug 2004
Location: Lexington, SC
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1986 Z28 Camaro
Engine: 350 with .440" lopey cam
Transmission: 6spd T56
Axle/Gears: Detroit Truetrac with 3.73 gears
autocross suspension setup suggestions?
Sorry, I'm sure people are tired of seeing posts like this but I couldn't really find anything recent.
I'm starting to autocross in my car. Currently I'm running original stock suspension so it's in major need of some upgrades. I'm going to be in the Street Modified class due to my engine upgrade that I've already done. The only suspension upgrade I have done so far is put a wonderbar on it.
What are peoples suggestions? I'm not looking for top of the line, but something mid level while I'm learning. If I get good and get serious about it then I'll look at dumping a lot of money in top of the line stuff.
Shocks / Struts.. I was thinking of going with something like tokico whites. Although I'm guessing most people will say Koni Yellows, I just hate how overpriced they are.
For springs, I was thinking of going with a set of Eibach Pro-Kit, maybe sportlines but I didn't want to lower it to much. Would either of these work, or are there a better option?
What else should I look at doing though? Sway bars? Suggestions on bushings? Strut towers? Anything else?
I'm assuming with the springs I'll need to do LCA relocation brackets, and a panhard bar, which I'd likely get from UMI performance. Would it be prudent to replace the LCAs themselves as well?
I was trying to talk to someone at stranoparts.com as that is who a couple guys at my first autocross event recommended to me, but the guy is incredibly hard to get in touch with. After a week of trying to get in touch with him on the phone I finally exchanged a couple emails with him, but then he just left the email kind of open ended without filling in a lot of details on the parts. One thing he did say was a Watts link, but I have no idea what that is? Have never heard of it before.
Eventually I'm also going to look at doing a set of wheels / tires dedicated to autocrossing, what size would be good for this? I run stock 245 / 50 / 16s right now on my iroc wheels for street. But at that size the best tire I can find is Ultra High Performance Summer tires. That is what I have on there right now a set of Firestone Firehawk Wide Oval Indy 500s. They didn't stick nearly as well as I had hoped on the autocross course. But I never completely lost the rear end either so I guess they didn't fail. However it's been suggested to me that I could do with something wider.
Thanks for any and all advice!
EDIT: Oh yeah, while I appreciate the opinion of those that think I should just leave my car unmodified while I'm learning, that isn't the suggestions I'm really looking for here. I'm going off the advice of a couple of the pro drivers I was talking with at my first event that told me I was driving good enough already to start looking at doing some upgrades to my car. They are the ones that told me I should look at an intermediate level setup for now.
I'm starting to autocross in my car. Currently I'm running original stock suspension so it's in major need of some upgrades. I'm going to be in the Street Modified class due to my engine upgrade that I've already done. The only suspension upgrade I have done so far is put a wonderbar on it.
What are peoples suggestions? I'm not looking for top of the line, but something mid level while I'm learning. If I get good and get serious about it then I'll look at dumping a lot of money in top of the line stuff.
Shocks / Struts.. I was thinking of going with something like tokico whites. Although I'm guessing most people will say Koni Yellows, I just hate how overpriced they are.
For springs, I was thinking of going with a set of Eibach Pro-Kit, maybe sportlines but I didn't want to lower it to much. Would either of these work, or are there a better option?
What else should I look at doing though? Sway bars? Suggestions on bushings? Strut towers? Anything else?
I'm assuming with the springs I'll need to do LCA relocation brackets, and a panhard bar, which I'd likely get from UMI performance. Would it be prudent to replace the LCAs themselves as well?
I was trying to talk to someone at stranoparts.com as that is who a couple guys at my first autocross event recommended to me, but the guy is incredibly hard to get in touch with. After a week of trying to get in touch with him on the phone I finally exchanged a couple emails with him, but then he just left the email kind of open ended without filling in a lot of details on the parts. One thing he did say was a Watts link, but I have no idea what that is? Have never heard of it before.
Eventually I'm also going to look at doing a set of wheels / tires dedicated to autocrossing, what size would be good for this? I run stock 245 / 50 / 16s right now on my iroc wheels for street. But at that size the best tire I can find is Ultra High Performance Summer tires. That is what I have on there right now a set of Firestone Firehawk Wide Oval Indy 500s. They didn't stick nearly as well as I had hoped on the autocross course. But I never completely lost the rear end either so I guess they didn't fail. However it's been suggested to me that I could do with something wider.
Thanks for any and all advice!
EDIT: Oh yeah, while I appreciate the opinion of those that think I should just leave my car unmodified while I'm learning, that isn't the suggestions I'm really looking for here. I'm going off the advice of a couple of the pro drivers I was talking with at my first event that told me I was driving good enough already to start looking at doing some upgrades to my car. They are the ones that told me I should look at an intermediate level setup for now.
Last edited by Steven6282; 03-02-2012 at 03:14 PM.
03-02-2012, 06:38 PM
#2
Supreme Member
iTrader: (1)
Join Date: Jul 1999
Posts: 3,257
Likes: 0
Received 5 Likes
on
3 Posts
Car: Turbo Buick
Engine: 3.8 V6
Re: autocross suspension setup suggestions?
These kinds of questions are hard to answer because you are basically asking to build an entire car without a budget to stick to, or a goal to aim for.
How much money do you have to spend is the number one question you need to answer, and if you are in SM, your goal should be to build it to the limit of the rules.
That said, your goals should be to get as set of autocross only wheels and tires. This is your number 1 most important upgrade, if you can, get 315s on all four corners.
Next to that is a package deal. Shocks, springs, bushings and ball joints. You are going to do this all at once, no sense in taking it apart three different times. Poly is adequate for the front control arms. You want a taller ball joint, howe makes up to .75 taller than stock now. If you get anything other than Koni you will be buying shocks twice, even with koni if you end up getting really serious, you will end up with custom shocks.
Springs are heavily dependent on preference, up front a moog 5664 spring with half coil cut works well for me. The springs and sway bars are part of your tuning. You might have a preference in how the car drives but generally, you want it to be neutral. You are going to play with sway bars (stock bar sizes are enough) until the car feels like the front end and the back end have equal amounts of grip.
This is going to be heavily dependent on how good you are behind the wheel. Rookies tend to what I call "over drive" the car, and this more often than not leads them to believe their car understeers. You have to be really conscious of what you are doing behind the wheel to figure out how you are going to change your tune for your next track outing.
So get your hands on both the 36/24 mm sway bar set, and the 34/21 set.
Pay no attention to the watts link business, that is not going to make you fast unless the weight of your wallet is slowing you down. Do some research on lowering your rear panhard bar, look into building your own panhard bar (tip, coleman racing and aluminum stock, qa1 rod ends...) and then you will need more rear spring rate to compensate
Don't worry about brake size for autoX, your stock brakes are fine. What you will need is an adjustable proportioning valve. Right now your rear brakes are doing almost nothing to slow down your car. You will need to tune this proportioning valve so that your rears lock just after your front tires do. This will change depending on track conditions, tires, etc.
Its just really too much to just spell out for you, making a car fast is an iterative process. You first have to know what your suspension is doing and how changes will affect it, and then you have to be able to identify what you want to change during each track outing. That is how you make your car fast, no one will ever nail a perfectly balanced race car their first time on the track.
I started with a 55 second lap at a local time attack and through the course of a year I slowly chipped away at lap times by identifying deficiencies and by the time I left, I had chopped 10 seconds off.
A lot of people are going to suggest all kinds of expensive tubular stuff but the vast majority of that stuff has very little bang for the buck. I dont have any of it, and I made my own phb and LCAs.
You have to look at bang for the buck, and to figure that out you have to understand what these parts are doing otherwise you are just throwing money at a car with no plan.
How much money do you have to spend is the number one question you need to answer, and if you are in SM, your goal should be to build it to the limit of the rules.
That said, your goals should be to get as set of autocross only wheels and tires. This is your number 1 most important upgrade, if you can, get 315s on all four corners.
Next to that is a package deal. Shocks, springs, bushings and ball joints. You are going to do this all at once, no sense in taking it apart three different times. Poly is adequate for the front control arms. You want a taller ball joint, howe makes up to .75 taller than stock now. If you get anything other than Koni you will be buying shocks twice, even with koni if you end up getting really serious, you will end up with custom shocks.
Springs are heavily dependent on preference, up front a moog 5664 spring with half coil cut works well for me. The springs and sway bars are part of your tuning. You might have a preference in how the car drives but generally, you want it to be neutral. You are going to play with sway bars (stock bar sizes are enough) until the car feels like the front end and the back end have equal amounts of grip.
This is going to be heavily dependent on how good you are behind the wheel. Rookies tend to what I call "over drive" the car, and this more often than not leads them to believe their car understeers. You have to be really conscious of what you are doing behind the wheel to figure out how you are going to change your tune for your next track outing.
So get your hands on both the 36/24 mm sway bar set, and the 34/21 set.
Pay no attention to the watts link business, that is not going to make you fast unless the weight of your wallet is slowing you down. Do some research on lowering your rear panhard bar, look into building your own panhard bar (tip, coleman racing and aluminum stock, qa1 rod ends...) and then you will need more rear spring rate to compensate
Don't worry about brake size for autoX, your stock brakes are fine. What you will need is an adjustable proportioning valve. Right now your rear brakes are doing almost nothing to slow down your car. You will need to tune this proportioning valve so that your rears lock just after your front tires do. This will change depending on track conditions, tires, etc.
Its just really too much to just spell out for you, making a car fast is an iterative process. You first have to know what your suspension is doing and how changes will affect it, and then you have to be able to identify what you want to change during each track outing. That is how you make your car fast, no one will ever nail a perfectly balanced race car their first time on the track.
I started with a 55 second lap at a local time attack and through the course of a year I slowly chipped away at lap times by identifying deficiencies and by the time I left, I had chopped 10 seconds off.
A lot of people are going to suggest all kinds of expensive tubular stuff but the vast majority of that stuff has very little bang for the buck. I dont have any of it, and I made my own phb and LCAs.
You have to look at bang for the buck, and to figure that out you have to understand what these parts are doing otherwise you are just throwing money at a car with no plan.
03-02-2012, 07:00 PM
#3
Supreme Member
iTrader: (1)
Join Date: Sep 2010
Location: Georgetown TX
Posts: 1,928
Likes: 0
Received 0 Likes
on
0 Posts
Car: Base 91 'bird
Engine: 3.1 v6
Transmission: 4L60
Axle/Gears: 9-bolt 3.27 & PBR
Re: autocross suspension setup suggestions?
On the other hand... You don't need to change anything. Unless you're an exception to the rule the car is way better than you are at this point and already handles fairly well. You'll take more off your times by driving better than you will with money. Unless you already have plenty of money save what you have for gas and new tires next season. There's a good chance you'll need. Meanwhile look for deals on upgrades. I found a set of ROH Snypers with almost new 275/40/17 tires for $500 so jumped on them. I only use them for auto-x so I don't wear them out! I know it'll cost plenty when they need replacing. As you get a better feel for the car as you get closer to it's limits start adding stuff to push the limits out some. Keep reading the suspension board too.
03-02-2012, 07:29 PM
#4
Member
Thread Starter
Join Date: Aug 2004
Location: Lexington, SC
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1986 Z28 Camaro
Engine: 350 with .440" lopey cam
Transmission: 6spd T56
Axle/Gears: Detroit Truetrac with 3.73 gears
Re: autocross suspension setup suggestions?
Thanks Pablo and Base91
To Pablo:
My budget atm would be around 1500 to 2000. I'm not looking for top end stuff here. I just want the car to handle better and not roll so much in the corners. Right now in things like slolums I have to really fight the steering on the car to get back. One of the pro drivers drove my car and even commented on how bad it was.
I'm thinking about right now just putting money into beefing up some stuff that I was going to do to the car anyway for the street, and then maybe next season when I learn more look at actually going after an autocross specific setup.
So I'm thinking about doing Eibach sportline springs, and Tokico Whites all around. Plus UMI adjustable LCAs, adjustable Panhardbar, LCA relocation brackets, caster and camber plates, and a 22mm rear sway bar (I didn't see any front sway bars on UMIs website, although I've already put a wonderbar on the car, is that the same thing as the front sway bar?). And then doing some new poly bushings on the parts that I'm not replacing.
Like I said it's not a specific autocross setup, but I think that will give the car better handling and make it more enjoyable not having to fight the steering so much. I'll probably also see about getting my steering box itself tightened up, and if needed replace the tie rods and such.
As for the wheels / tires, thats the most expensive thing. Lol looks like I'm not gonna get out of a new set of wheels and tires for less than 1500 by themselves. So I may just run what I have for now.
I just want the car to be more enjoyable to drive while I'm learning this first season.
To Base91:
I don't really know how good or bad I am right now. All I can compare to right now is a mustang driven by one of the pros at the last event I was at. His best time was 27.4, mine was 27.7. I can say with certainty the car is far from handling well at this point lol. The only other thing I've driven to compare it to is my friends miata that is already setup with entry level stuff, and it's like night and day. I know part of that is due to the miata being smaller though.
To Pablo:
My budget atm would be around 1500 to 2000. I'm not looking for top end stuff here. I just want the car to handle better and not roll so much in the corners. Right now in things like slolums I have to really fight the steering on the car to get back. One of the pro drivers drove my car and even commented on how bad it was.
I'm thinking about right now just putting money into beefing up some stuff that I was going to do to the car anyway for the street, and then maybe next season when I learn more look at actually going after an autocross specific setup.
So I'm thinking about doing Eibach sportline springs, and Tokico Whites all around. Plus UMI adjustable LCAs, adjustable Panhardbar, LCA relocation brackets, caster and camber plates, and a 22mm rear sway bar (I didn't see any front sway bars on UMIs website, although I've already put a wonderbar on the car, is that the same thing as the front sway bar?). And then doing some new poly bushings on the parts that I'm not replacing.
Like I said it's not a specific autocross setup, but I think that will give the car better handling and make it more enjoyable not having to fight the steering so much. I'll probably also see about getting my steering box itself tightened up, and if needed replace the tie rods and such.
As for the wheels / tires, thats the most expensive thing. Lol looks like I'm not gonna get out of a new set of wheels and tires for less than 1500 by themselves. So I may just run what I have for now.
I just want the car to be more enjoyable to drive while I'm learning this first season.
To Base91:
I don't really know how good or bad I am right now. All I can compare to right now is a mustang driven by one of the pros at the last event I was at. His best time was 27.4, mine was 27.7. I can say with certainty the car is far from handling well at this point lol. The only other thing I've driven to compare it to is my friends miata that is already setup with entry level stuff, and it's like night and day. I know part of that is due to the miata being smaller though.
03-02-2012, 08:17 PM
#5
Senior Member
Join Date: Jun 2009
Location: Evansville, IN
Posts: 511
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1983 Z28
Engine: Forged 355
Transmission: 700r4
Axle/Gears: 2.73
Re: autocross suspension setup suggestions?
I honestly think you will see the most improvement from some good quality shocks and struts along with some tires. Good tires might run $350+ a tire so budget that in, If you are laying down that much on tires, you my as well spend the dough on some nice wheels!
03-03-2012, 10:18 PM
#6
Junior Member
Join Date: Oct 2011
Location: Bay Area
Posts: 75
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1992 RS
Engine: 94 LT1
Transmission: T5
Axle/Gears: 10 Bolt 3.42
Re: autocross suspension setup suggestions?
i think the general consensus around here is that sub frame connectors would be one of the first things to get. shocks are very important too, i have the tokico illumi or whatever they're called and they are nice,(although i haven't driven my car much).
and if you're looking to lower you car i would recommend weight jacks from ground control, they're pricy, but for me nothing beats arriving at the gtg and being able to drop your car uber low for runs, then raise it back up for the drive home.
and if you're looking to lower you car i would recommend weight jacks from ground control, they're pricy, but for me nothing beats arriving at the gtg and being able to drop your car uber low for runs, then raise it back up for the drive home.
03-03-2012, 11:10 PM
#7
Member
Thread Starter
Join Date: Aug 2004
Location: Lexington, SC
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1986 Z28 Camaro
Engine: 350 with .440" lopey cam
Transmission: 6spd T56
Axle/Gears: Detroit Truetrac with 3.73 gears
Re: autocross suspension setup suggestions?
i think the general consensus around here is that sub frame connectors would be one of the first things to get. shocks are very important too, i have the tokico illumi or whatever they're called and they are nice,(although i haven't driven my car much).
and if you're looking to lower you car i would recommend weight jacks from ground control, they're pricy, but for me nothing beats arriving at the gtg and being able to drop your car uber low for runs, then raise it back up for the drive home.
and if you're looking to lower you car i would recommend weight jacks from ground control, they're pricy, but for me nothing beats arriving at the gtg and being able to drop your car uber low for runs, then raise it back up for the drive home.
I don't know what I'm doing about springs yet. Someone I believe to know what they are talking about that has been doing autocross for a while told me not to do anything with the springs yet, just do the shocks and struts for now. Worry about springs later when I get better at driving, and get my shocks and struts revalved for the spring rate that I get then.
Speaking of the shocks and struts, I just ordered some Koni yellows. If anyone else is looking tirerack.com has them on sale for 20% off right now. 162 dollars cheaper than their normal price for a set of 4. They are on sale until sometime in May according to the site, but who knows how stock will be.
EDIT:
Question about LCAs, is there any real reason to have adjustable LCAs, or would I be fine with non adjustables, if I even replace them?
Last edited by Steven6282; 03-03-2012 at 11:25 PM.
Trending Topics
03-04-2012, 07:41 AM
#8
Supreme Member
iTrader: (14)
Join Date: Aug 2006
Location: Central NJ
Posts: 12,650
Likes: 0
Received 44 Likes
on
42 Posts
Car: 86 Trans Am, 92 Firebird
Engine: 408 sbc, 3.1L of raw power
Transmission: TKO600, T5
Axle/Gears: Moser 9", 3:70 trutac, 3:23 torsion
Re: autocross suspension setup suggestions?
If you do rear control arms DO NOT get non adjustable ones with poly.bushings, that's a huge step backwards. Use rod ends if you don't mind some noise. Like Pable said you can piece together your own and save some money.
Start with wheels tires and shocks struts. Koni yellows were a god choice. Get the largest wheel and tire you can fit, and some good tires. With large tires a wonderbar is some good cheap insurance to keep the front frame from moving, and using strut mounts with bearings instead of tbe stock rubber will help noticable.
Take care of that first, see what you think after the next season, and upgrade parts.from therd as needed.
Start with wheels tires and shocks struts. Koni yellows were a god choice. Get the largest wheel and tire you can fit, and some good tires. With large tires a wonderbar is some good cheap insurance to keep the front frame from moving, and using strut mounts with bearings instead of tbe stock rubber will help noticable.
Take care of that first, see what you think after the next season, and upgrade parts.from therd as needed.
03-04-2012, 11:03 AM
#9
Member
Thread Starter
Join Date: Aug 2004
Location: Lexington, SC
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1986 Z28 Camaro
Engine: 350 with .440" lopey cam
Transmission: 6spd T56
Axle/Gears: Detroit Truetrac with 3.73 gears
Re: autocross suspension setup suggestions?
If you do rear control arms DO NOT get non adjustable ones with poly.bushings, that's a huge step backwards. Use rod ends if you don't mind some noise. Like Pable said you can piece together your own and save some money.
Start with wheels tires and shocks struts. Koni yellows were a god choice. Get the largest wheel and tire you can fit, and some good tires. With large tires a wonderbar is some good cheap insurance to keep the front frame from moving, and using strut mounts with bearings instead of tbe stock rubber will help noticable.
Take care of that first, see what you think after the next season, and upgrade parts.from therd as needed.
Start with wheels tires and shocks struts. Koni yellows were a god choice. Get the largest wheel and tire you can fit, and some good tires. With large tires a wonderbar is some good cheap insurance to keep the front frame from moving, and using strut mounts with bearings instead of tbe stock rubber will help noticable.
Take care of that first, see what you think after the next season, and upgrade parts.from therd as needed.
http://www.umiperformance.com/catalo...e2b2ba4fb3d08a
And yeah I already have a wonder bar on the car, that is the only suspension upgrade I have done on the car before this lol.
Also can you explain to me how non adjustable ones with poly bushings is a step backwards from stock? I'm not really too concerned with replacing them right now since I'm not lowering the car, but to put new bushings on them is 55 dollars at Spohn, half the price of a new set of non adjustable ones from UMI. Figured it would be smarter to just go ahead and replace them than spend the money on bushings now and then replace them again in the not to distant future. Not sure if the bushings are available anywhere else for a better price or not, I probably need to replace a lot of my bushings, but I can't find anywhere that sales a complete set. The sets on summit for example don't have A-arm bushings in them and I think there were one or two other that I didn't see in the set.
EDIT: or how about these for strut mounts? Just found them, and they look to be about the same as UMI's but a lot cheaper:
http://www.foundersperformance.com/p...er-Plates.html
And actually they look to have a few things that look just as good as UMI stuff but for a lot cheaper. Bolt in LCA relocation brackets at half the cost of UMIs. Adjustable Panhard and LCA packages for 50 dollars cheaper... Anyone used these guys? Their parts are described as being the same as UMI stuff so I see no reason to pay more for UMI if they are good.
Last edited by Steven6282; 03-04-2012 at 11:51 AM.
03-04-2012, 12:24 PM
#10
Senior Member
Join Date: Jun 2009
Location: Evansville, IN
Posts: 511
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1983 Z28
Engine: Forged 355
Transmission: 700r4
Axle/Gears: 2.73
Re: autocross suspension setup suggestions?
I personally would go with those adjustable founders plates, and you can't beat that price!
Last edited by TheMonster; 03-04-2012 at 01:04 PM.
03-04-2012, 12:38 PM
#11
Senior Member
Join Date: Jun 2009
Location: Evansville, IN
Posts: 511
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1983 Z28
Engine: Forged 355
Transmission: 700r4
Axle/Gears: 2.73
Re: autocross suspension setup suggestions?
Trip post, stupid android phone! 
Last edited by TheMonster; 03-04-2012 at 01:04 PM.
03-04-2012, 12:39 PM
#12
Senior Member
Join Date: Jun 2009
Location: Evansville, IN
Posts: 511
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1983 Z28
Engine: Forged 355
Transmission: 700r4
Axle/Gears: 2.73
Re: autocross suspension setup suggestions?
trip post
Last edited by TheMonster; 03-04-2012 at 01:03 PM.
03-04-2012, 12:41 PM
#13
Member
Thread Starter
Join Date: Aug 2004
Location: Lexington, SC
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1986 Z28 Camaro
Engine: 350 with .440" lopey cam
Transmission: 6spd T56
Axle/Gears: Detroit Truetrac with 3.73 gears
Re: autocross suspension setup suggestions?
Yeah I did some searching and found some reviews the majority of which said founders where just as good of quality as UMI. So I just ordered from them. Also read they got subframe connectors coming out soon that are similarly priced cheap, if so I'll probably pick those up when they come out too 
So I think the majority of my suspension stuff is taken care of for now. Might still need to get a few bushings, about to go outside and change my oil and inspect the old bushings to see how bad of shape they are in now.
One other question about the camber plates. I know the alignment works off these, should I just have an alignment shop install these for me so they are aligned right then, or is it possible for me to install them and then get the car to a shop to have the alignment done? I've never done alignment myself to know how to do that part of it lol.
So I think the majority of my suspension stuff is taken care of for now. Might still need to get a few bushings, about to go outside and change my oil and inspect the old bushings to see how bad of shape they are in now.
One other question about the camber plates. I know the alignment works off these, should I just have an alignment shop install these for me so they are aligned right then, or is it possible for me to install them and then get the car to a shop to have the alignment done? I've never done alignment myself to know how to do that part of it lol.
03-04-2012, 02:43 PM
#14
Supreme Member
iTrader: (14)
Join Date: Aug 2006
Location: Central NJ
Posts: 12,650
Likes: 0
Received 44 Likes
on
42 Posts
Car: 86 Trans Am, 92 Firebird
Engine: 408 sbc, 3.1L of raw power
Transmission: TKO600, T5
Axle/Gears: Moser 9", 3:70 trutac, 3:23 torsion
Re: autocross suspension setup suggestions?
you can install them yourself, just try to eyeball it somewhat close to where it was before, then have it aligned. I would not drive it much till it gets aligned, dont want to wear the tires out.
03-04-2012, 03:00 PM
#15
Re: autocross suspension setup suggestions?
Pay no attention to the watts link business, that is not going to make you fast unless the weight of your wallet is slowing you down. Do some research on lowering your rear panhard bar, look into building your own panhard bar (tip, coleman racing and aluminum stock, qa1 rod ends...) and then you will need more rear spring rate to compensate
Coleman racing has swedged tubes... is that what I should be making rear LCA's out of?
http://www.colemanracing.com/Trailin...eel-P4054.aspx
Or is this better:
http://www.colemanracing.com/Trailin...eel-P4052.aspx
I can measure the length of my rear LCA's pretty easy, but how much room for adjustment should I give for my rod ends? How much space does a rod end take up on each end of the rod? In short... how can I figure out how long I need my tubing?
And I could get 4 of these rod ends:
http://www.colemanracing.com/Rod-End...uty-P4337.aspx
But I think I still need the inner sleeve bushing things for them which I cant seem to find, but either way that means it'll probably cost around...$150 or so for a home made pair of rear LCA's.
This seems like an excellent idea, but I see why people dont do this all the time.
Last edited by InfernalVortex; 03-04-2012 at 03:13 PM.
03-04-2012, 03:22 PM
#16
Supreme Member
iTrader: (14)
Join Date: Aug 2006
Location: Central NJ
Posts: 12,650
Likes: 0
Received 44 Likes
on
42 Posts
Car: 86 Trans Am, 92 Firebird
Engine: 408 sbc, 3.1L of raw power
Transmission: TKO600, T5
Axle/Gears: Moser 9", 3:70 trutac, 3:23 torsion
Re: autocross suspension setup suggestions?
you would want a 3/4" rod end with a 3/4 bore, then a sleave to reduce it to 12mm or 1/2, spacers to take up the slack.
a typical 3/4 rod end and nut will add 1.5" to the end of the tubing.
Heavy wall (.095 or better) swedged tubing will work, and solid threaded aluminum will work too.
People do it, been done for years. A lot of people just dont know where or how to build these parts or where to find good parts, or what good parts even are.
Some parts you just cant find in a generic catalog though, so sometimes its easier to just buy a premade piece, bolt on and go.
a typical 3/4 rod end and nut will add 1.5" to the end of the tubing.
Heavy wall (.095 or better) swedged tubing will work, and solid threaded aluminum will work too.
People do it, been done for years. A lot of people just dont know where or how to build these parts or where to find good parts, or what good parts even are.
Some parts you just cant find in a generic catalog though, so sometimes its easier to just buy a premade piece, bolt on and go.
03-04-2012, 05:46 PM
#17
Member
Thread Starter
Join Date: Aug 2004
Location: Lexington, SC
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1986 Z28 Camaro
Engine: 350 with .440" lopey cam
Transmission: 6spd T56
Axle/Gears: Detroit Truetrac with 3.73 gears
Re: autocross suspension setup suggestions?
I need one more thing cleared up if anyone could please. Are the Front Control Arm Bushings the same thing as the A Arm bushings?
When I was under the car earlier I don't remember seeing any other control arms up front with bushings, but I could've missed it. Summit has Front Control Arm bushings, but no A Arm bushings. Spohn is the opposite, they list A Arm bushings but no front control arm bushings lol. The Bushing set at hawks only lists Front and Rear Control Arms as well with no mention of A Arms.
When I was under the car earlier I don't remember seeing any other control arms up front with bushings, but I could've missed it. Summit has Front Control Arm bushings, but no A Arm bushings. Spohn is the opposite, they list A Arm bushings but no front control arm bushings lol. The Bushing set at hawks only lists Front and Rear Control Arms as well with no mention of A Arms.
03-04-2012, 05:50 PM
#18
Supreme Member
iTrader: (14)
Join Date: Aug 2006
Location: Central NJ
Posts: 12,650
Likes: 0
Received 44 Likes
on
42 Posts
Car: 86 Trans Am, 92 Firebird
Engine: 408 sbc, 3.1L of raw power
Transmission: TKO600, T5
Axle/Gears: Moser 9", 3:70 trutac, 3:23 torsion
Re: autocross suspension setup suggestions?
I need one more thing cleared up if anyone could please. Are the Front Control Arm Bushings the same thing as the A Arm bushings?
When I was under the car earlier I don't remember seeing any other control arms up front with bushings, but I could've missed it. Summit has Front Control Arm bushings, but no A Arm bushings. Spohn is the opposite, they list A Arm bushings but no front control arm bushings lol. The Bushing set at hawks only lists Front and Rear Control Arms as well with no mention of A Arms.
When I was under the car earlier I don't remember seeing any other control arms up front with bushings, but I could've missed it. Summit has Front Control Arm bushings, but no A Arm bushings. Spohn is the opposite, they list A Arm bushings but no front control arm bushings lol. The Bushing set at hawks only lists Front and Rear Control Arms as well with no mention of A Arms.
03-04-2012, 08:23 PM
#19
Senior Member
Join Date: Jul 2008
Location: Ft Wayne, IN
Posts: 808
Likes: 0
Received 2 Likes
on
2 Posts
Car: 2003 F-150
Engine: 4.6L Modular V8
Transmission: 4R70W
Axle/Gears: Ford 8.8"/3.55 LSD
Re: autocross suspension setup suggestions?
Don't worry about brake size for autoX, your stock brakes are fine. What you will need is an adjustable proportioning valve. Right now your rear brakes are doing almost nothing to slow down your car. You will need to tune this proportioning valve so that your rears lock just after your front tires do.
Its just really too much to just spell out for you, making a car fast is an iterative process. You first have to know what your suspension is doing and how changes will affect it, and then you have to be able to identify what you want to change during each track outing. That is how you make your car fast, no one will ever nail a perfectly balanced race car their first time on the track.
Chassis
Wheels & Tires
Suspension
Brakes
Powertrain
First thing is torsional stiffness. Second is getting the power to the ground in a useable form. Third is reducing suspension bind. Fourth is stopping. Fifth is having a proper powerplant & drivetrain that matches the car. This is a bit academic, but its a huge step in the right direction.
Getting the Center of Gravity (CG) of the car closer to the ground is always a good thing, but doing this with drop springs is less help than you think. The roll centers will all still be in the same places in relation to each other & the CG, while closer to the ground will still be in the same place in the chassis. You'd also need drop spindles up front to maintain proper steering geometry. I'd stick with stock height replacement Moog springs for now until you can afford to reduce the topside weight of the car.
A good middle of the road choice. Better than stock, allows for weight jacks if you ever want to go to those, and they are adjustable. But Koni's Yellows, while expensive, are the best shock you can buy.
Plus UMI adjustable LCAs adjustable Panhardbar, LCA relocation brackets, caster and camber plates, and a 22mm rear sway bar (I didn't see any front sway bars on UMIs website, although I've already put a wonderbar on the car, is that the same thing as the front sway bar?). And then doing some new poly bushings on the parts that I'm not replacing.
If you are just getting into AX, I highly recommend that you do not get LCA relocation brackets just yet. They change how your Instant Center moves under braking & acceleration. I've talked to Ramey @ UMI and these are a very drag race oriented part. They change the LCA angle so that the IC is moved farther to the rear for improved traction. While this is good, it also limits how far forward your IC can go under brakeing which is terrible. What you'd gain on corner exit would be lost brakeing for corner entry.
The Wonderbar is a front chassis stiffener, not a suspension piece. All it does is tie together the front subframe at the steering box area. While UMI makes a good sway bar, Spohn makes a solid sway bar kit. Solid bars, while heavier, are far stiffer than hollow bars.
Do not under any circumstances get poly bushings for anything other than the front control arms. Poly bushings are far stiffer and bind far faster than the stock rubber bushings do. Bind is a killer in AX. At the bare minimum, since you are going with all adjustable parts, get rod ends as they are cheap to replace and will never bind. Poly bushings are a great cheap way to make your car go fast in a straight line, not go fast round turns.
If your asking what Bind is, its the point at which the bushing deflection rate changes. This causes the suspension to not travel smoothly throughout its range of motion. Heres a great link on what bind is and how to eliminate it:
http://www.elephantracing.com/techtopic/binding.htm
Like I said it's not a specific autocross setup, but I think that will give the car better handling and make it more enjoyable not having to fight the steering so much. I'll probably also see about getting my steering box itself tightened up, and if needed replace the tie rods and such.
I also noticed that you left out an adjustable torque arm. This will help out alot as well. It'll allow you to dial in your pinion angle, remove the mounting point from the transmission
So, for a good $1500-$2000 parts list, this is what you'll need (from most to least important):
1.) UMI Sub-Frame Connectors $210 http://www.umiperformance.com/catalo...roducts_id=127
2.) 16x8 IROC wheels $450 http://www.hawksthirdgenparts.com/ca...wheelsset.aspx
3.) Tires for the IROC wheels $850 http://www.summitracing.com/parts/HOO-17325/
4.) Tokico Illuminas all round ($175 ea front, $120 ea rear) $590 http://www.spohn.net/shop/1982-1992-...Shocks-Struts/
5.) Moog Springs all round ($85/pair front, $90/pair rear) $175 http://www.spohn.net/shop/1982-1992-...s-Accessories/
6.) Spohn Front End rebuild kit (with ball joints) $350 http://www.spohn.net/shop/1982-1992-...GM-F-Body.html
7.) UMI adjustable RLCA's & PHB Package (Rod Ends) $365 http://www.umiperformance.com/catalo...roducts_id=142 Same package with Roto Joints $405
7.) Spohn Adjustable TQA (with Rod End on front mount) $410 http://www.spohn.net/shop/1982-1992-...nsmission.html
8.) Spohn Sway Bar set $349 http://www.spohn.net/shop/1982-1992-...rome-Moly.html
9.) Hawks 1LE Brake Kit $850 http://www.hawksthirdgenparts.com/1l...kepackage.aspx
10.) Hawks Rear Disc Brake Kit with Parking Brake $475 http://www.hawksthirdgenparts.com/82...ersionkit.aspx
11.) Adjustable proportioning valve about $100 from Summit/Jegs
12.) Caster Camber Plates about $220 from UMI, Hot Part, or Racecraft
13.) Strut tower brace about $150 depending on what you get
14.) Limited Slip Differential $150-$500 depending on what kind of LSD you choose.
The first 3 items will run $1510 + shipping and these will give you the greatest bang for the buck and these will get you about 60-70% of the performance for AX you need. The next 3 items will cost you another $1115 + shipping get you another 10-15% of the performance for AX. The remaining 15% of your AX performance will come from the remaining part of the list. So for $2600 you get a solid base for either Drag racing or AX and great AX performance.
For some good reading on the pros & cons of a PHB compared to a Watts link, search this forum & read this for more info:
http://www.stranoparts.com/partdetai...D=65&ModelID=9
$650 for a watts link, but it completely changes your rear end kinematics for the better.
Last edited by 89_RS; 03-04-2012 at 08:28 PM.
03-04-2012, 09:03 PM
#20
Member
Thread Starter
Join Date: Aug 2004
Location: Lexington, SC
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1986 Z28 Camaro
Engine: 350 with .440" lopey cam
Transmission: 6spd T56
Axle/Gears: Detroit Truetrac with 3.73 gears
Re: autocross suspension setup suggestions?
A watts link is a serious upgrade over the panhard bar. It locates the rear roll center in relation to the chassis. With a PHB, the roll center is free to change based on how much the axle tracks, which creates a jacking effect making the rear feel like its all over the place. However; given his budget, an adjustable rod end/ball & socket panhard bar is preferable.
Stock brakes are not adequate for AutoX. I had my brakes replaced about a month before I went to my first AX, and they had at most 200 miles on them. In 6 runs, I warped my rotors and destroyed my pads. At a bare minimum, I'd suggest a 1LE kit from Hawks with an adjustable prop valve. If he had some more budget, a Hawks rear disc brake kit as well.
Making a car faster is an iterative process, but its not hard to figure out. All the guys who do ALMS racing that I've talked to say that it goes in this order:
Chassis
Wheels & Tires
Suspension
Brakes
Powertrain
First thing is torsional stiffness. Second is getting the power to the ground in a useable form. Third is reducing suspension bind. Fourth is stopping. Fifth is having a proper powerplant & drivetrain that matches the car. This is a bit academic, but its a huge step in the right direction.
Its good you have a budget in mind, that will greatly help in parts selection. The age of your suspension is the killer here, not the parts currently on it. Its in the it needs one of everything stage. From the factory, these cars were great for AX, but age takes a toll on everything. My car has the exact same problem. My springs, shocks, and bushings are all wore out so the car just rolls like a bourbon barrel.
Getting the Center of Gravity (CG) of the car closer to the ground is always a good thing, but doing this with drop springs is less help than you think. The roll centers will all still be in the same places in relation to each other & the CG, while closer to the ground will still be in the same place in the chassis. You'd also need drop spindles up front to maintain proper steering geometry. I'd stick with stock height replacement Moog springs for now until you can afford to reduce the topside weight of the car.
A good middle of the road choice. Better than stock, allows for weight jacks if you ever want to go to those, and they are adjustable. But Koni's Yellows, while expensive, are the best shock you can buy.
UMI Adjustable RLCA's, PHB, C&C Plates, are great choices for getting going on AX. If you want to run on the street more, I suggest you get the Roto Joint version of the RLCA's & PHB as they have Delrin bushings to limit road noise. Rod ends are cheaper, easier to replace, but cause more noise. C&C plates can be added later if you want more AX performance.
If you are just getting into AX, I highly recommend that you do not get LCA relocation brackets just yet. They change how your Instant Center moves under braking & acceleration. I've talked to Ramey @ UMI and these are a very drag race oriented part. They change the LCA angle so that the IC is moved farther to the rear for improved traction. While this is good, it also limits how far forward your IC can go under brakeing which is terrible. What you'd gain on corner exit would be lost brakeing for corner entry.
The Wonderbar is a front chassis stiffener, not a suspension piece. All it does is tie together the front subframe at the steering box area. While UMI makes a good sway bar, Spohn makes a solid sway bar kit. Solid bars, while heavier, are far stiffer than hollow bars.
Do not under any circumstances get poly bushings for anything other than the front control arms. Poly bushings are far stiffer and bind far faster than the stock rubber bushings do. Bind is a killer in AX. At the bare minimum, since you are going with all adjustable parts, get rod ends as they are cheap to replace and will never bind. Poly bushings are a great cheap way to make your car go fast in a straight line, not go fast round turns.
If your asking what Bind is, its the point at which the bushing deflection rate changes. This causes the suspension to not travel smoothly throughout its range of motion. Heres a great link on what bind is and how to eliminate it:
http://www.elephantracing.com/techtopic/binding.htm
Getting the steering system rebuilt will help a ton. A front end rebuild kit & a rebuilt steering box are a must.
It depends. I'm not current on the SM wheel & tire rules as I'm setting up for CXP (pretty much all out without getting into F-Mod). If you can find a set of Aluminum 16x8 IROC wheels and some decent Hoosier tires, you should be good. Hawks has a set of those wheels for $450, but you might luck out at your local pick-a-part place.
I also noticed that you left out an adjustable torque arm. This will help out alot as well. It'll allow you to dial in your pinion angle, remove the mounting point from the transmission
It already is enjoyable as you are wanting to go back & do it again. If your car isn't a rust bucket like mine is, I'd suggest you keep driving your stock car for now. You'll learn a ton about recovering from bad situations that way. Also, as Pablo has said, us rookies do overdrive our cars. My first lap was an 88.4s, second was 72.5s, next was 70s and after that I was pretty consistent around 70s. Just getting a feel for the course & learning how to drive your car will make you a faster driver. Then, when you have all those go fast goodies, you'll begin to see where you can cut even more time.
So, for a good $1500-$2000 parts list, this is what you'll need (from most to least important):
1.) UMI Sub-Frame Connectors $210 http://www.umiperformance.com/catalo...roducts_id=127
2.) 16x8 IROC wheels $450 http://www.hawksthirdgenparts.com/ca...wheelsset.aspx
3.) Tires for the IROC wheels $850 http://www.summitracing.com/parts/HOO-17325/
4.) Tokico Illuminas all round ($175 ea front, $120 ea rear) $590 http://www.spohn.net/shop/1982-1992-...Shocks-Struts/
5.) Moog Springs all round ($85/pair front, $90/pair rear) $175 http://www.spohn.net/shop/1982-1992-...s-Accessories/
6.) Spohn Front End rebuild kit (with ball joints) $350 http://www.spohn.net/shop/1982-1992-...GM-F-Body.html
7.) UMI adjustable RLCA's & PHB Package (Rod Ends) $365 http://www.umiperformance.com/catalo...roducts_id=142 Same package with Roto Joints $405
7.) Spohn Adjustable TQA (with Rod End on front mount) $410 http://www.spohn.net/shop/1982-1992-...nsmission.html
8.) Spohn Sway Bar set $349 http://www.spohn.net/shop/1982-1992-...rome-Moly.html
9.) Hawks 1LE Brake Kit $850 http://www.hawksthirdgenparts.com/1l...kepackage.aspx
10.) Hawks Rear Disc Brake Kit with Parking Brake $475 http://www.hawksthirdgenparts.com/82...ersionkit.aspx
11.) Adjustable proportioning valve about $100 from Summit/Jegs
12.) Caster Camber Plates about $220 from UMI, Hot Part, or Racecraft
13.) Strut tower brace about $150 depending on what you get
14.) Limited Slip Differential $150-$500 depending on what kind of LSD you choose.
The first 3 items will run $1510 + shipping and these will give you the greatest bang for the buck and these will get you about 60-70% of the performance for AX you need. The next 3 items will cost you another $1115 + shipping get you another 10-15% of the performance for AX. The remaining 15% of your AX performance will come from the remaining part of the list. So for $2600 you get a solid base for either Drag racing or AX and great AX performance.
For some good reading on the pros & cons of a PHB compared to a Watts link, search this forum & read this for more info:
http://www.stranoparts.com/partdetai...D=65&ModelID=9
$650 for a watts link, but it completely changes your rear end kinematics for the better.
Stock brakes are not adequate for AutoX. I had my brakes replaced about a month before I went to my first AX, and they had at most 200 miles on them. In 6 runs, I warped my rotors and destroyed my pads. At a bare minimum, I'd suggest a 1LE kit from Hawks with an adjustable prop valve. If he had some more budget, a Hawks rear disc brake kit as well.
Making a car faster is an iterative process, but its not hard to figure out. All the guys who do ALMS racing that I've talked to say that it goes in this order:
Chassis
Wheels & Tires
Suspension
Brakes
Powertrain
First thing is torsional stiffness. Second is getting the power to the ground in a useable form. Third is reducing suspension bind. Fourth is stopping. Fifth is having a proper powerplant & drivetrain that matches the car. This is a bit academic, but its a huge step in the right direction.
Its good you have a budget in mind, that will greatly help in parts selection. The age of your suspension is the killer here, not the parts currently on it. Its in the it needs one of everything stage. From the factory, these cars were great for AX, but age takes a toll on everything. My car has the exact same problem. My springs, shocks, and bushings are all wore out so the car just rolls like a bourbon barrel.
Getting the Center of Gravity (CG) of the car closer to the ground is always a good thing, but doing this with drop springs is less help than you think. The roll centers will all still be in the same places in relation to each other & the CG, while closer to the ground will still be in the same place in the chassis. You'd also need drop spindles up front to maintain proper steering geometry. I'd stick with stock height replacement Moog springs for now until you can afford to reduce the topside weight of the car.
A good middle of the road choice. Better than stock, allows for weight jacks if you ever want to go to those, and they are adjustable. But Koni's Yellows, while expensive, are the best shock you can buy.
UMI Adjustable RLCA's, PHB, C&C Plates, are great choices for getting going on AX. If you want to run on the street more, I suggest you get the Roto Joint version of the RLCA's & PHB as they have Delrin bushings to limit road noise. Rod ends are cheaper, easier to replace, but cause more noise. C&C plates can be added later if you want more AX performance.
If you are just getting into AX, I highly recommend that you do not get LCA relocation brackets just yet. They change how your Instant Center moves under braking & acceleration. I've talked to Ramey @ UMI and these are a very drag race oriented part. They change the LCA angle so that the IC is moved farther to the rear for improved traction. While this is good, it also limits how far forward your IC can go under brakeing which is terrible. What you'd gain on corner exit would be lost brakeing for corner entry.
The Wonderbar is a front chassis stiffener, not a suspension piece. All it does is tie together the front subframe at the steering box area. While UMI makes a good sway bar, Spohn makes a solid sway bar kit. Solid bars, while heavier, are far stiffer than hollow bars.
Do not under any circumstances get poly bushings for anything other than the front control arms. Poly bushings are far stiffer and bind far faster than the stock rubber bushings do. Bind is a killer in AX. At the bare minimum, since you are going with all adjustable parts, get rod ends as they are cheap to replace and will never bind. Poly bushings are a great cheap way to make your car go fast in a straight line, not go fast round turns.
If your asking what Bind is, its the point at which the bushing deflection rate changes. This causes the suspension to not travel smoothly throughout its range of motion. Heres a great link on what bind is and how to eliminate it:
http://www.elephantracing.com/techtopic/binding.htm
Getting the steering system rebuilt will help a ton. A front end rebuild kit & a rebuilt steering box are a must.
It depends. I'm not current on the SM wheel & tire rules as I'm setting up for CXP (pretty much all out without getting into F-Mod). If you can find a set of Aluminum 16x8 IROC wheels and some decent Hoosier tires, you should be good. Hawks has a set of those wheels for $450, but you might luck out at your local pick-a-part place.
I also noticed that you left out an adjustable torque arm. This will help out alot as well. It'll allow you to dial in your pinion angle, remove the mounting point from the transmission
It already is enjoyable as you are wanting to go back & do it again. If your car isn't a rust bucket like mine is, I'd suggest you keep driving your stock car for now. You'll learn a ton about recovering from bad situations that way. Also, as Pablo has said, us rookies do overdrive our cars. My first lap was an 88.4s, second was 72.5s, next was 70s and after that I was pretty consistent around 70s. Just getting a feel for the course & learning how to drive your car will make you a faster driver. Then, when you have all those go fast goodies, you'll begin to see where you can cut even more time.
So, for a good $1500-$2000 parts list, this is what you'll need (from most to least important):
1.) UMI Sub-Frame Connectors $210 http://www.umiperformance.com/catalo...roducts_id=127
2.) 16x8 IROC wheels $450 http://www.hawksthirdgenparts.com/ca...wheelsset.aspx
3.) Tires for the IROC wheels $850 http://www.summitracing.com/parts/HOO-17325/
4.) Tokico Illuminas all round ($175 ea front, $120 ea rear) $590 http://www.spohn.net/shop/1982-1992-...Shocks-Struts/
5.) Moog Springs all round ($85/pair front, $90/pair rear) $175 http://www.spohn.net/shop/1982-1992-...s-Accessories/
6.) Spohn Front End rebuild kit (with ball joints) $350 http://www.spohn.net/shop/1982-1992-...GM-F-Body.html
7.) UMI adjustable RLCA's & PHB Package (Rod Ends) $365 http://www.umiperformance.com/catalo...roducts_id=142 Same package with Roto Joints $405
7.) Spohn Adjustable TQA (with Rod End on front mount) $410 http://www.spohn.net/shop/1982-1992-...nsmission.html
8.) Spohn Sway Bar set $349 http://www.spohn.net/shop/1982-1992-...rome-Moly.html
9.) Hawks 1LE Brake Kit $850 http://www.hawksthirdgenparts.com/1l...kepackage.aspx
10.) Hawks Rear Disc Brake Kit with Parking Brake $475 http://www.hawksthirdgenparts.com/82...ersionkit.aspx
11.) Adjustable proportioning valve about $100 from Summit/Jegs
12.) Caster Camber Plates about $220 from UMI, Hot Part, or Racecraft
13.) Strut tower brace about $150 depending on what you get
14.) Limited Slip Differential $150-$500 depending on what kind of LSD you choose.
The first 3 items will run $1510 + shipping and these will give you the greatest bang for the buck and these will get you about 60-70% of the performance for AX you need. The next 3 items will cost you another $1115 + shipping get you another 10-15% of the performance for AX. The remaining 15% of your AX performance will come from the remaining part of the list. So for $2600 you get a solid base for either Drag racing or AX and great AX performance.
For some good reading on the pros & cons of a PHB compared to a Watts link, search this forum & read this for more info:
http://www.stranoparts.com/partdetai...D=65&ModelID=9
$650 for a watts link, but it completely changes your rear end kinematics for the better.
However, I'm sure you can imagine how annoying it is to be told so many different things. Some of what you say I've had people tell me the exact opposite of. For example bushings... I've had other pro auto crossers tell me poly bushings where the way to go. I've had some tell me poly in the front but something softer in the rear.
And it's not just bushings but everything lol. I think I've been told about every option there is to work on the car as being the right way to do it and the way to do it first =p. I've had others tell me LCA relocation brackets are great for autocross to reduce any wheel hop in corners.
Also, just to point out, if you are listing stuff from Hawks I can likely find it elsewhere for half the price. Hawks is so overpriced on just about everything they sale that it's laughable. The only things they don't overprice are items that are mass produced and sold at a lot of other places too (like headliners), they tend to price match on those.
I've already ordered most of the stuff that I'm going to be using for now until I get more competitive.
Koni Yellows all the way around
Founders Caster / Camber Plates
Spohns Sway Bar set
And replacement bushings (and yes I went with poly bushings).
I've still got to:
Find someone locally that can rebuild my steering box
Find some sort of Posi rear end.
Get another set of wheels and tires for use in racing only
Subframe connectors
Not sure what I'm going to do on the rear end yet. I've been told a torsen tr2+ in my stock rear end would be good, but I don't want to spend the money on one of those and then swap the rear end later for a 9 bolt and it not fit. I eventually want to get a 9 bolt because I'll need bolt in axles for some stuff I'll be doing in the future. I thought about going with a Ford 9 inch but I don't think my Iroc Wheels (already have a set of Iroc wheels btw) will fit that. Not so much concerned with the Iroc Wheels for racing applications, but for street. This car will not be a dedicated race car. I'll still drive it on the street sometimes.
That brings me to the wheels and tires. This will be one of the things I'm keeping an eye out for. For now I'm just gonna run my Irocs with my street tires (Firehawk Wide Oval Indy 500s) on them, until I can find a good deal on another set of wheels. Once I find some wheels then I'll look into tires for them.
Subframe connectors, I'll wait until Founders releases theirs. They are so much cheaper than UMI and all the reviews I find say the quality is about the same. So not gonna dump the money into UMI stuff.
So anyway, maybe you are right and the others that have told me were wrong and the poly bushings aren't ideal for auto crossing. They can't be any worse than my worn out dry rotted rubber crap on there now. So I'll make do with them until I get more competitive and learn exactly what I need
As for the enjoyable part, I did say more enjoyable
Yes the car is fun enough now that it got me hooked. I just want it to be a little more fun and a little less fighting the worn out steering. I think what I've picked up so far and the couple things I have left planned to do will take care of that.EDIT: Oh yeah, I'm gonna fab my own Strut tower brace. I can build one of those for about 40 dollars. As for the front end rebuild kit, I'm gonna wait until I can have a mechanic look at my steering for that. I inspected the parts today and currently there isn't any play in the steering components. It's all tight and looks relatively in good condition considering the age. If a mechanic tells me I need to replace the stuff to fix steering then I will, but I think most of my steering issues is coming from the suspension. Even the steering wheel itself is fairly responsive if I'm going in a straight line, there isn't a lot of play in it. It's when I'm cornering and trying to go back the other way that it really begins to have problems. As for brakes, that ultimately depends on what I end up doing with my rear end. I'll be more concerned with brakes when I'm going fast enough to make the ones I have now hold me back
EDIT2: I do wonder if I should replace my ball joints on my control arms as well? Guess I may as well. Doing the bushings might as well do the ball joints to just to be sure.
Last edited by Steven6282; 03-04-2012 at 09:42 PM.
03-04-2012, 10:15 PM
#21
Senior Member
Join Date: Jul 2008
Location: Ft Wayne, IN
Posts: 808
Likes: 0
Received 2 Likes
on
2 Posts
Car: 2003 F-150
Engine: 4.6L Modular V8
Transmission: 4R70W
Axle/Gears: Ford 8.8"/3.55 LSD
Re: autocross suspension setup suggestions?
Some of what you say I've had people tell me the exact opposite of. For example bushings... I've had other pro auto crossers tell me poly bushings where the way to go. I've had some tell me poly in the front but something softer in the rear.
And it's not just bushings but everything lol. I think I've been told about every option there is to work on the car as being the right way to do it and the way to do it first =p. I've had others tell me LCA relocation brackets are great for autocross to reduce any wheel hop in corners.
And it's not just bushings but everything lol. I think I've been told about every option there is to work on the car as being the right way to do it and the way to do it first =p. I've had others tell me LCA relocation brackets are great for autocross to reduce any wheel hop in corners.
For me, all that I learned about suspension for AX/RR came from 3 years of building suspensions for Formula SAE cars. The guy that taught me what I know about suspension professionally raced (read, made a living that fed him and paid his bills) for 2 years in Formula Mazda & Formula 3 out at Sears Point in CA (Infineon Raceway if you follow NASCAR). So I tend to put more stock in what he taught me than what I hear at the track.
Also, just to point out, if you are listing stuff from Hawks I can likely find it elsewhere for half the price. Hawks is so overpriced on just about everything they sale that it's laughable. The only things they don't overprice are items that are mass produced and sold at a lot of other places too (like headliners), they tend to price match on those.
This will cause the car to become "twitchy". As the suspension moves through its range of motion, the load required to make the bushing deflect follows a quadratic curve, which means its not a linear relationship:
http://en.wikipedia.org/wiki/Quadratic_equation
Other words, the farther thru its range of motion the suspension travels, the greater the resistance the bushing puts on the suspension. Eventually, you'll hit a point in the range of motion where the suspension stops traveling and the need to travel keeps increasing. This is called bind. Eventually the suspension gets loaded up to the point that the bushing will continue to deflect, causing a snap change in the suspension kinematics. This is a very grave thing to have happen when performing multiple quick maneuvers in rapid succession. This isn't something that I'm making up, any serious AX person who has actually done there homework will tell you this.
http://www.elephantracing.com/techtopic/binding.htm
Not sure what I'm going to do on the rear end yet. I've been told a torsen tr2+ in my stock rear end would be good, but I don't want to spend the money on one of those and then swap the rear end later for a 9 bolt and it not fit. I eventually want to get a 9 bolt because I'll need bolt in axles for some stuff I'll be doing in the future.
Tech article on the 10-Bolt:
https://www.thirdgen.org/beefinguprear
That brings me to the wheels and tires. This will be one of the things I'm keeping an eye out for. For now I'm just gonna run my Irocs with my street tires (Firehawk Wide Oval Indy 500s) on them, until I can find a good deal on another set of wheels. Once I find some wheels then I'll look into tires for them.
So anyway, maybe you are right and the others that have told me were wrong and the poly bushings aren't ideal for auto crossing. They can't be any worse than my worn out dry rotted rubber crap on there now. So I'll make do with them until I get more competitive and learn exactly what I need
EDIT: Oh yeah, I'm gonna fab my own Strut tower brace. I can build one of those for about 40 dollars. As for the front end rebuild kit, I'm gonna wait until I can have a mechanic look at my steering for that. I inspected the parts today and currently there isn't any play in the steering components. It's all tight and looks relatively in good condition considering the age. If a mechanic tells me I need to replace the stuff to fix steering then I will, but I think most of my steering issues is coming from the suspension. Even the steering wheel itself is fairly responsive if I'm going in a straight line, there isn't a lot of play in it. It's when I'm cornering and trying to go back the other way that it really begins to have problems. As for brakes, that ultimately depends on what I end up doing with my rear end. I'll be more concerned with brakes when I'm going fast enough to make the ones I have now hold me back
Your current brakes won't hold you back, they'll just eat your wallet up in repairs.
I'm not trying to be argumentative here, just trying to save you money by not paying for the same performance upgrade twice.
03-04-2012, 11:03 PM
#22
Member
Thread Starter
Join Date: Aug 2004
Location: Lexington, SC
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1986 Z28 Camaro
Engine: 350 with .440" lopey cam
Transmission: 6spd T56
Axle/Gears: Detroit Truetrac with 3.73 gears
Re: autocross suspension setup suggestions?
What are you needing a 9-bolt for that a 10-bolt won't do? If its a power issue, both are limited to the same power level (both fail around 450ft/lbs) because the ring gears are all in the same size range 7.5" to 7.75". LSD's are differential specific, so a 10-bolt diff won't fit a 9-bolt. Also, TORSEN's aren't the only geared LSD option. Eaton sells the Detroit Truetrac for $350 and its on par with the TORSEN.
Tech article on the 10-Bolt:
https://www.thirdgen.org/beefinguprear
Tech article on the 10-Bolt:
https://www.thirdgen.org/beefinguprear
I wouldn't bet on it. Their 4th gen SFC's are dirt cheap because the 4th gen is a different chassis with only one real SFC mounting area. Thirdgens have two areas, outboard by the rockers & inboard along the trans tunnel. Spohn/UMI/BRM all make perimeter style SFC's while Alston & MAC make inboard SFC's. The cheapest thridgen SFC's are MAC's @ $160.
Nothing wrong with not shelling out for new wheels & tires. But, if you do get serious, your best bang for the buck in improving the suspension is sinking all the money you can afford to into wheels & tires.
Driving down the road & taking turns really hard are two different animals. Yes, the suspension is a bit of a problem here, but you'll get alot out of a rebuilt box, new pump, and at the bare minimum an alignment. I'd strongly suggest a rebuild kit because who knows how many miles are on those linkages. They do wear out and need to be replaced sometime.
New ball joints in the A-Arms will help alot. And poly bushings in the A-Arms won't hurt them as the A-Arm only rotates about that point. Poly bushings being used in places where two axis need to move & the third needs to remain fixed is a problem.
I'm not trying to be argumentative here, just trying to save you money by not paying for the same performance upgrade twice.
But that is one reason I ultimately decided to go with Koni Yellows. When I get competitive enough to get set springs with a set rebound rate, I can get them revalved to match as needed, where as tokico illumina's I would not have been able to do that. Also I got the koni yellows at 20% off
Last edited by Steven6282; 03-04-2012 at 11:07 PM.
03-04-2012, 11:29 PM
#23
Senior Member
Join Date: Jul 2008
Location: Ft Wayne, IN
Posts: 808
Likes: 0
Received 2 Likes
on
2 Posts
Car: 2003 F-150
Engine: 4.6L Modular V8
Transmission: 4R70W
Axle/Gears: Ford 8.8"/3.55 LSD
Re: autocross suspension setup suggestions?
It's not about the strength, it's about bolt in axles. I've been told some road course and track events which I also plan to do some of, require bolt in axles to even get on their track. 10 bolts don't have bolt ins, 9 bolts do, and a 9 bolt from a 88 to 92 camaro or firebird, will have 28 spline axles for a little added strength, and have the larger diameter disc brakes (11.3 inch I think).
We'll see when they come out. They are a cheaper on everything else, if they aren't cheaper on the SFC that will be the first item they aren't. Look at Founders LCA relocation brackets, 50 dollars for bolt ins vs UMIs 100 dollars. Adjustable Panhard bars and adjustable LCAs set 180 dollars vs UMI 285. Their Caster / Camber plates were 170 where UMis were 220.
I'm not trying to be argumentative either, I really appreciate the feedback. I've already made a few purchases and if I have to repurchase the same item 6 months down the road so be it. I'll chalk it up to a learning fee. Yeah I'm a little annoyed that I may have purchased the wrong stuff based on wrong information given, but oh well, I'll get over it.
But that is one reason I ultimately decided to go with Koni Yellows. When I get competitive enough to get set springs with a set rebound rate, I can get them revalved to match as needed, where as tokico illumina's I would not have been able to do that. Also I got the koni yellows at 20% off
But that is one reason I ultimately decided to go with Koni Yellows. When I get competitive enough to get set springs with a set rebound rate, I can get them revalved to match as needed, where as tokico illumina's I would not have been able to do that. Also I got the koni yellows at 20% off
03-04-2012, 11:43 PM
#24
Re: autocross suspension setup suggestions?
What do you guys think of putting rubber bushings into tubular rear LCA's? You get hte benefit of stiff, strong control arms for hard launches, and the tendency to bind would, I imagine, be greatly reduced. Will a stock style rubber bushing fit in the average aftermarket rear LCA?
03-05-2012, 03:44 AM
#25
Supreme Member
iTrader: (1)
Join Date: Jul 1999
Posts: 3,257
Likes: 0
Received 5 Likes
on
3 Posts
Car: Turbo Buick
Engine: 3.8 V6
Re: autocross suspension setup suggestions?
Hah. Doogie Howser showed up to tell me all about what he learned in school.
Doogie, at these autoX events you have attended, how did you stack up against the competition?
I have the American car track record for Adams motorsports park, which includes a faster lap time than Mary Pozzi's 73 Camaro (which you will drive in the next Gran Turismo video game), how about you?
Tell me more about this panhard bar jacking, and feeling of "all over the place". I will be sure to relay the information to the back of my car so it knows how it should behave. Be sure to let Ford know that their Boss 302 should not be utterly destroying the M3 on the track, after all, they run a panhard bar and the M3 has IRS
Got news for you, the lcas "jack" too, and so does the torque arm.. better just dump the whole setup.
The PHB is long, and when level jacking is minimized, more so when you have good control of the chassis. The goal is to transmit force in the same plane as the bar laterally.
There's a saying a wise engineer (who worked on the thirdgen f body) once said "excellence is not so much about type as it is about execution"
Now I see you are telling me all about brakes. I understand you "had your brakes replaced" after some autoX. First off, changing pads is part of the game so your best bet it to learn how to do this stuff yourself. Brake pads will wear quickly, parts store pads are not designed to handle the heat, the binder breaks down and the friction material cracks. Second, here is a pro tip for you: When coming off the course, don't use your e brake, or sit on your brakes for any reason. In fact, don't sit stopped with hot brakes engaged ever. You can send me the money you were paying people to do your brakes as a thanks.
That said, I have stock brakes with an adjustable proportioning valve, parts store dot 4, and I have never experienced brake fade. Even after multiple hot laps in riverside CA in 100 degree ambient temps. This is at auto x speeds. If you want to go run the nurburgring, by all means get some ZR1 carbon whiz bang brakes or scale accordingly, but the guy asked about auto x. You don't need much heat capacity for autoX. You would have a heart attack if you saw what some Miata guys do to their brake rotors for autoX. Re-defines "cross drilled"
Torsional rigidity, please tell me more... I am all ears. I take it you have measured this on a thirdgen (which would be a first on this forum, and possibly outside of gm) or, on any chassis? Tell me how this is done (quick, google). Might want to quantify if if you want to play engineer.
Now for the rest of it, I didn't go through line by line but a couple of things stood out:
"Getting the Center of Gravity (CG) of the car closer to the ground is always a good thing, but doing this with drop springs is less help than you think. The roll centers will all still be in the same places in relation to each other & the CG, while closer to the ground will still be in the same place in the chassis. You'd also need drop spindles up front to maintain proper steering geometry. I'd stick with stock height replacement Moog springs for now until you can afford to reduce the topside weight of the car."
There are several incorrect statements here, roll centers are not in the same places in relation to eachother, the front roll center drops drastically while the rear does not. It would be great if they didn't and you could just drop the cg as you described, but this isn't what happens. This is why I recommend taller ball joints and lowering the phb. This reduces the roll axis inclination. Drop spindles accomplish the same thing, as that is their primary purpose. They do not "correct" steering geometry.
Now lets look at the list you provided
So, for a good $1500-$2000 parts list, this is what you'll need (from most to least important):
1.) UMI Sub-Frame Connectors $210 http://www.umiperformance.com/catalo...roducts_id=127
2.) 16x8 IROC wheels $450 http://www.hawksthirdgenparts.com/ca...wheelsset.aspx
3.) Tires for the IROC wheels $850 http://www.summitracing.com/parts/HOO-17325/
4.) Tokico Illuminas all round ($175 ea front, $120 ea rear) $590 http://www.spohn.net/shop/1982-1992-...Shocks-Struts/
5.) Moog Springs all round ($85/pair front, $90/pair rear) $175 http://www.spohn.net/shop/1982-1992-...s-Accessories/
6.) Spohn Front End rebuild kit (with ball joints) $350 http://www.spohn.net/shop/1982-1992-...GM-F-Body.html
7.) UMI adjustable RLCA's & PHB Package (Rod Ends) $365 http://www.umiperformance.com/catalo...roducts_id=142 Same package with Roto Joints $405
7.) Spohn Adjustable TQA (with Rod End on front mount) $410 http://www.spohn.net/shop/1982-1992-...nsmission.html
8.) Spohn Sway Bar set $349 http://www.spohn.net/shop/1982-1992-...rome-Moly.html
9.) Hawks 1LE Brake Kit $850 http://www.hawksthirdgenparts.com/1l...kepackage.aspx
10.) Hawks Rear Disc Brake Kit with Parking Brake $475 http://www.hawksthirdgenparts.com/82...ersionkit.aspx
11.) Adjustable proportioning valve about $100 from Summit/Jegs
12.) Caster Camber Plates about $220 from UMI, Hot Part, or Racecraft
13.) Strut tower brace about $150 depending on what you get
14.) Limited Slip Differential $150-$500 depending on what kind of LSD you choose.
Steven, if you follow this list and in this order, you are going to be out of a lot of money without much in return.
Wheels and tires, very important
good shocks, spring combo, very important
adj prop valve, very important
Limited slip, very important
SFCs, not a bad idea but not required. Several thirdgens managed to win ESP nationals for years without sfcs. And they aren't that far behind CP times.
aftermarket sway bars, total waste of money. Stock stuff is more than adequate, in fact, the 24 is too big for 95% of people.
Spohn tq arm... no. You do not want this. The tq arm is designed to move fore and aft in addition to rotating about a lateral axis. Having it fixed to a point at the front introduces bind which is what Doogie was ranting about. It should also pose minimal restriction of rotation about its longitudinal axis. just an fyi. Look at how the GW track link mounts the nose of the torque arm for an example. That leaves only one direction the torque arm must be stiff in. Think about it.
I run a stock torque arm. Can you gain something with a tq arm upgrade? Maybe. It's far enough down my list that I have a GW track link that I have never installed. I'm not in a rush to discover more brake hop if it's there to be found.
big brakes, don't need em for autox. 4 wheel disks, pbr rears is adequate. Get some better brake fluid, and might be a good idea to get some auto x pads. I ran as fast as I did on parts store pads though, fwiw.
Strut tower brace. Way down the list. I don't have one. You need to be generating some cornering force in order to be concerned about the outside strut tower pulling outward and reducing camber. You aren't going to have that condition if you are on puny tires. Strut tower stiffness is quoted at 30,000 lbs per inch which they tested with a hydraulic ram. Maybe Doogie can whip out his TI-83 and figure out the cornering force to deflection numbers. They didn't say if that was between the strut towers or individually so maybe work out for 15,000 lb/inch too. That's going to be lateral outward load from the outside tire levering the strut outward.
Caster camber plate, good idea, helps get more camber and caster. That said, get one that has a good bearing retention design. Spohn for example, uses a snap ring which is terrible because the bearing pounds itself loose against the ring and knocks like crazy.
With the money you saved on that list, buy konis, and bigger wheels/tires
Doogie, at these autoX events you have attended, how did you stack up against the competition?
I have the American car track record for Adams motorsports park, which includes a faster lap time than Mary Pozzi's 73 Camaro (which you will drive in the next Gran Turismo video game), how about you?
Tell me more about this panhard bar jacking, and feeling of "all over the place". I will be sure to relay the information to the back of my car so it knows how it should behave. Be sure to let Ford know that their Boss 302 should not be utterly destroying the M3 on the track, after all, they run a panhard bar and the M3 has IRS
Got news for you, the lcas "jack" too, and so does the torque arm.. better just dump the whole setup.
The PHB is long, and when level jacking is minimized, more so when you have good control of the chassis. The goal is to transmit force in the same plane as the bar laterally.
There's a saying a wise engineer (who worked on the thirdgen f body) once said "excellence is not so much about type as it is about execution"
Now I see you are telling me all about brakes. I understand you "had your brakes replaced" after some autoX. First off, changing pads is part of the game so your best bet it to learn how to do this stuff yourself. Brake pads will wear quickly, parts store pads are not designed to handle the heat, the binder breaks down and the friction material cracks. Second, here is a pro tip for you: When coming off the course, don't use your e brake, or sit on your brakes for any reason. In fact, don't sit stopped with hot brakes engaged ever. You can send me the money you were paying people to do your brakes as a thanks.
That said, I have stock brakes with an adjustable proportioning valve, parts store dot 4, and I have never experienced brake fade. Even after multiple hot laps in riverside CA in 100 degree ambient temps. This is at auto x speeds. If you want to go run the nurburgring, by all means get some ZR1 carbon whiz bang brakes or scale accordingly, but the guy asked about auto x. You don't need much heat capacity for autoX. You would have a heart attack if you saw what some Miata guys do to their brake rotors for autoX. Re-defines "cross drilled"
Torsional rigidity, please tell me more... I am all ears. I take it you have measured this on a thirdgen (which would be a first on this forum, and possibly outside of gm) or, on any chassis? Tell me how this is done (quick, google). Might want to quantify if if you want to play engineer.
Now for the rest of it, I didn't go through line by line but a couple of things stood out:
"Getting the Center of Gravity (CG) of the car closer to the ground is always a good thing, but doing this with drop springs is less help than you think. The roll centers will all still be in the same places in relation to each other & the CG, while closer to the ground will still be in the same place in the chassis. You'd also need drop spindles up front to maintain proper steering geometry. I'd stick with stock height replacement Moog springs for now until you can afford to reduce the topside weight of the car."
There are several incorrect statements here, roll centers are not in the same places in relation to eachother, the front roll center drops drastically while the rear does not. It would be great if they didn't and you could just drop the cg as you described, but this isn't what happens. This is why I recommend taller ball joints and lowering the phb. This reduces the roll axis inclination. Drop spindles accomplish the same thing, as that is their primary purpose. They do not "correct" steering geometry.
Now lets look at the list you provided
So, for a good $1500-$2000 parts list, this is what you'll need (from most to least important):
1.) UMI Sub-Frame Connectors $210 http://www.umiperformance.com/catalo...roducts_id=127
2.) 16x8 IROC wheels $450 http://www.hawksthirdgenparts.com/ca...wheelsset.aspx
3.) Tires for the IROC wheels $850 http://www.summitracing.com/parts/HOO-17325/
4.) Tokico Illuminas all round ($175 ea front, $120 ea rear) $590 http://www.spohn.net/shop/1982-1992-...Shocks-Struts/
5.) Moog Springs all round ($85/pair front, $90/pair rear) $175 http://www.spohn.net/shop/1982-1992-...s-Accessories/
6.) Spohn Front End rebuild kit (with ball joints) $350 http://www.spohn.net/shop/1982-1992-...GM-F-Body.html
7.) UMI adjustable RLCA's & PHB Package (Rod Ends) $365 http://www.umiperformance.com/catalo...roducts_id=142 Same package with Roto Joints $405
7.) Spohn Adjustable TQA (with Rod End on front mount) $410 http://www.spohn.net/shop/1982-1992-...nsmission.html
8.) Spohn Sway Bar set $349 http://www.spohn.net/shop/1982-1992-...rome-Moly.html
9.) Hawks 1LE Brake Kit $850 http://www.hawksthirdgenparts.com/1l...kepackage.aspx
10.) Hawks Rear Disc Brake Kit with Parking Brake $475 http://www.hawksthirdgenparts.com/82...ersionkit.aspx
11.) Adjustable proportioning valve about $100 from Summit/Jegs
12.) Caster Camber Plates about $220 from UMI, Hot Part, or Racecraft
13.) Strut tower brace about $150 depending on what you get
14.) Limited Slip Differential $150-$500 depending on what kind of LSD you choose.
Steven, if you follow this list and in this order, you are going to be out of a lot of money without much in return.
Wheels and tires, very important
good shocks, spring combo, very important
adj prop valve, very important
Limited slip, very important
SFCs, not a bad idea but not required. Several thirdgens managed to win ESP nationals for years without sfcs. And they aren't that far behind CP times.
aftermarket sway bars, total waste of money. Stock stuff is more than adequate, in fact, the 24 is too big for 95% of people.
Spohn tq arm... no. You do not want this. The tq arm is designed to move fore and aft in addition to rotating about a lateral axis. Having it fixed to a point at the front introduces bind which is what Doogie was ranting about. It should also pose minimal restriction of rotation about its longitudinal axis. just an fyi. Look at how the GW track link mounts the nose of the torque arm for an example. That leaves only one direction the torque arm must be stiff in. Think about it.
I run a stock torque arm. Can you gain something with a tq arm upgrade? Maybe. It's far enough down my list that I have a GW track link that I have never installed. I'm not in a rush to discover more brake hop if it's there to be found.
big brakes, don't need em for autox. 4 wheel disks, pbr rears is adequate. Get some better brake fluid, and might be a good idea to get some auto x pads. I ran as fast as I did on parts store pads though, fwiw.
Strut tower brace. Way down the list. I don't have one. You need to be generating some cornering force in order to be concerned about the outside strut tower pulling outward and reducing camber. You aren't going to have that condition if you are on puny tires. Strut tower stiffness is quoted at 30,000 lbs per inch which they tested with a hydraulic ram. Maybe Doogie can whip out his TI-83 and figure out the cornering force to deflection numbers
. They didn't say if that was between the strut towers or individually so maybe work out for 15,000 lb/inch too. That's going to be lateral outward load from the outside tire levering the strut outward.Caster camber plate, good idea, helps get more camber and caster. That said, get one that has a good bearing retention design. Spohn for example, uses a snap ring which is terrible because the bearing pounds itself loose against the ring and knocks like crazy.
With the money you saved on that list, buy konis, and bigger wheels/tires
Last edited by Pablo; 03-05-2012 at 01:35 PM.
03-05-2012, 06:16 PM
#26
Senior Member
Join Date: Jul 2008
Location: Ft Wayne, IN
Posts: 808
Likes: 0
Received 2 Likes
on
2 Posts
Car: 2003 F-150
Engine: 4.6L Modular V8
Transmission: 4R70W
Axle/Gears: Ford 8.8"/3.55 LSD
Re: autocross suspension setup suggestions?
Fine Pablo, explain in graphic visceral detail why your setup is superior to all others and why we should listen solely to you and you alone when it comes to suspension. To me, you're just someone on the internet with a distinct hate for people with different points of view, be they right or wrong.
So please, enlighten me and all others in this thread so that we may walk the true path of righteousness when suspensions are involved.
So please, enlighten me and all others in this thread so that we may walk the true path of righteousness when suspensions are involved.
03-05-2012, 07:32 PM
#27
Re: autocross suspension setup suggestions?
Pablo, how do you feel about a the stock torque arm for lowered cars? Is the whole pinion angle thing not a very big deal?
Also, curious, I know LCARBS are GREAT for drag racing and launches, but how important is it for autocross? Is it a detriment?
Also, curious, I know LCARBS are GREAT for drag racing and launches, but how important is it for autocross? Is it a detriment?
Last edited by InfernalVortex; 03-05-2012 at 07:36 PM.
03-06-2012, 08:12 AM
#28
Supreme Member
iTrader: (1)
Join Date: Jul 1999
Posts: 3,257
Likes: 0
Received 5 Likes
on
3 Posts
Car: Turbo Buick
Engine: 3.8 V6
Re: autocross suspension setup suggestions?
Fine Pablo, explain in graphic visceral detail why your setup is superior to all others and why we should listen solely to you and you alone when it comes to suspension. To me, you're just someone on the internet with a distinct hate for people with different points of view, be they right or wrong.
So please, enlighten me and all others in this thread so that we may walk the true path of righteousness when suspensions are involved.
So please, enlighten me and all others in this thread so that we may walk the true path of righteousness when suspensions are involved.
Last edited by Pablo; 03-06-2012 at 09:28 AM.
03-06-2012, 08:37 AM
#29
Supreme Member
iTrader: (1)
Join Date: Jul 1999
Posts: 3,257
Likes: 0
Received 5 Likes
on
3 Posts
Car: Turbo Buick
Engine: 3.8 V6
Re: autocross suspension setup suggestions?
I have not measured the pinion angle with the stock torque arm. That said, I do not think it is a big deal.
Practically speaking the only reason to worry about pinion angle is to prevent a driveshaft imbalance. You want the u joints moving in phase and at the same amplitude so their imbalance cancels each other out.
A secondary reason is to help the U joints live longer. That's it.
I actually ate some crow on this topic myself not too long ago, there are some interesting articles online about it
If the pinion angle is set to 0 stock, and you lower the car, this is going to give you a slightly negative angle. Many drag racing people suggest going 2 negative so that under acceleration you end up with zero.
I think the change will be minimal since the tq arm is so long. Whatever angle change in the torque arm is going to be roughly the change in your pinion angle.
Anyway, pinion angle in and of itself is independent of your suspension and has no bearing on how your car handles. Just vibration and longevity.
LCARB, they are important because you want your lcas at about level to minimize these jacking effects or whatever you want to call them. If you lower the car much you are going to end up with arms angled upward. Any angle away from the direction forces are imparted is going to want to make the LCA rotate toward that direction.
Accelerate with those angled up and the rear is going to want to move up toward the body, this is a loss of traction. Angled down can lead to funny business like brake hop. Another thing that happens is that you will get some rear steering as one arm gets effectively shorter and one gets longer if you don't start out from level. Dean talked about this in one of his posts where he argued in favor of rear steer to the inside of the turn. Starting from level if you lean to one side of the car that arm goes up roughly the same amount the other goes down so both sides of the rear end will move forward the same amount. This is one reason you don't want a fixed mount at the front of the tq arm.
03-06-2012, 07:24 PM
#30
Senior Member
Join Date: Jul 2008
Location: Ft Wayne, IN
Posts: 808
Likes: 0
Received 2 Likes
on
2 Posts
Car: 2003 F-150
Engine: 4.6L Modular V8
Transmission: 4R70W
Axle/Gears: Ford 8.8"/3.55 LSD
Re: autocross suspension setup suggestions?
Before you edited your post, I had a chance to read it. I'll try to reply to your comments as you wrote them.
First off, I wasn't saying or implying in any way that you were full of ****. If I had, I would have said it. I don't beat around the bush or sugar coat things. You stated emphatically that stock brakes were more than enough, and in your particular situation that is true. In my situation, the reverse is true. My setup was a completely factory setup with new parts that had 200 miles on them. The only difference I can come up with for warping the rotors in a single AX event was that when I started my first lap, it was 45* out with rain falling & 2" of standing water on the track. By my third lap, it was sunny & 75* and the track was still wet. At the end of my sixth lap, it was 80+ & bone dry. Track temp measured well over a 100 at that point. Its possible the thermal shock of freezing water on a 1000* rotor warped them, but even my mechanic had his doubts about that. FWIW, my stock brakes are 10.5"x1.1" solid vented rotors with a two piston caliper up front & drum brakes in the rear with a stock proportioning valve. I posted up about this and several others replied that the stock brakes aren't all that alot of people make them out to be. Am I being a leming, maybe. But my experience was far different from yours and I had listened to you and other guys specifically say that stock brakes were just fine for AX prior to going.
The Lesson learned here: Take everything you read on the internet with a huge grain of salt.
Secondly, I'm not studying engineering at all. Graduated college a year ago. I have two degrees, one in architectural design & one in construction management. What I learned about suspension came from spending 3 years in the mechanical engineering machine shop while in college designing, fabricating, & assembling suspension parts for Purdue's Formula SAE team. I was taught how to machine & weld by two life long machinists, both with 30+ years experience in custom machining & fabricating. The flip side of this hands on work was being taught how to design the suspension itself from someone who had raced professionally & for a living before going to college to become an ME for a race team. The guy who taught me about the principles & theories of suspension design raced full time in Formula Mazda & on occasion Formula 3 at Sears Point raceway for 2 years. The more advanced stuff I learned from talking with the judges at Formula SAE competitions, specifically Steve Fox & Claude Rouelle. In case you are unfamiliar with FSAE, its a program that was established by the Big 3 to produce solid vehicle designers in college so that they can hit the ground running in the real world without spending years developing theoretical teachings into practical real world knowledge & skills. I decided to join FSAE because I wanted to learn about cars. I put anywhere from 40-60hrs a week into that in addition to taking 15-18 credits every semester in construction & building design. And I did design a quite interesting part while in FSAE: an integrated CV Housing/Output shaft machined from a single billet of Aermet 340. The part weighed just under 2lbs, but it could handle 150hp. In fact, several of the ME students I showed it to told me it would fail. When it came to destructive testing of this part, the CV tripod & solid 1" diameter Titanium halfshaft were the parts that failed. Now, thats not to say I've not had my fair share or more of failures (it took an awful lot of screw ups to come up with a working CV Housing/Output shaft) but I learned from my mistakes and improved because of them.
Lesson here, never assume that the person your slamming your fist down on has absolutely no knowledge & experience in the subject. Clearly, something got taken the wrong way here by both of us, so its clear there is a communication problem of some kind.
Finally, I'm not some "but the math says" TI-83 wielding know it all engineer. I'm a project manager who spends his days solving problems that rarely involve math, rather they involve critical thinking, sorta like playing chess but in this game all the choices matter. The most complicated math I do on a regular basis involves static analysis of simple bridge structures that carry 80000lb or more loads. Occasionally, I'm asked to evaluate the effects of 75+ ton machines moving on those bridges or do ground pressure/ground hydraulic pressure calculations to determine if building will sink into or manholes will float out of ground using my TI-92 Plus (and this is because I do simple integrations to find a likely range of outcomes). Clearly, manholes don't float in dirt, but I still have to prove to a civil engineer that it won't happen, so I know quite well that math isn't the end all be all of life. However; a tiny portion (big emphasis on tiny) of the math I learned applies to designing a suspension. As you can tell, I'm not the strongest in mechanical engineering math, but having a good working understanding of the parts involved & their relationships with one another greatly helps. It also helps to have a good sense of intuition. I can't mathematically prove something will or won't work, but past experiences and current knowledge often get me to the right answer. Often times, I'm accused of overdesigning & overbuilding things because I really don't want them to fail.
As for your statement that I'm going to get someone killed with my suggestions, you bear that same burden as well. Same goes for all of us who make suggestions to people here when it involves suggesting that a person does X or Y because we had a good experience when we did X or Y. If they go out & do X, but not X the way you did it (and this is generally because we all are guilty of leaving out that one critical detail because its common sense to us and not someone else), and incur a serious injury or fatally wound themselves, their blood is on your hands. And I'm not just saying this from an academic perspective, I've had more near death experiences than I care to count because of the what people have said I should or shouldn't do.
Last edited by 89_RS; 03-06-2012 at 08:16 PM.
04-01-2012, 06:18 AM
#31
Supreme Member
Join Date: Aug 2011
Location: Aloha, Oregon
Posts: 1,178
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1991 Christine Z28
Engine: RV Cam and Intake 350 SBC
Transmission: 5speed
Axle/Gears: 3.08 ls Posi
Re: autocross suspension setup suggestions?
I'm going to stand behind the advice of getting new wheels and new tires, if not wheels then tires. New tires make a WORLD of difference, even on the stock suspension. I went from being able to slide into ditches in the twisties to being able to take them at 5 and 10 over the recommended speeds.
07-06-2014, 07:35 PM
#32
Junior Member
Re: autocross suspension setup suggestions?
I'm going to stand behind the advice of getting new wheels and new tires, if not wheels then tires. New tires make a WORLD of difference, even on the stock suspension. I went from being able to slide into ditches in the twisties to being able to take them at 5 and 10 over the recommended speeds.
07-07-2014, 03:00 PM
#33
Senior Member
Join Date: Jun 2003
Location: Rockville, MD
Posts: 828
Likes: 0
Received 2 Likes
on
2 Posts
Car: 1989 Camaro RS
Engine: Ellis Juan
Transmission: t-56
Re: autocross suspension setup suggestions?
So you can build your own rear LCA's then?
Coleman racing has swedged tubes... is that what I should be making rear LCA's out of?
http://www.colemanracing.com/Trailin...eel-P4054.aspx
Or is this better:
http://www.colemanracing.com/Trailin...eel-P4052.aspx
I can measure the length of my rear LCA's pretty easy, but how much room for adjustment should I give for my rod ends? How much space does a rod end take up on each end of the rod? In short... how can I figure out how long I need my tubing?
And I could get 4 of these rod ends:
http://www.colemanracing.com/Rod-End...uty-P4337.aspx
But I think I still need the inner sleeve bushing things for them which I cant seem to find, but either way that means it'll probably cost around...$150 or so for a home made pair of rear LCA's.
This seems like an excellent idea, but I see why people dont do this all the time.
Coleman racing has swedged tubes... is that what I should be making rear LCA's out of?
http://www.colemanracing.com/Trailin...eel-P4054.aspx
Or is this better:
http://www.colemanracing.com/Trailin...eel-P4052.aspx
I can measure the length of my rear LCA's pretty easy, but how much room for adjustment should I give for my rod ends? How much space does a rod end take up on each end of the rod? In short... how can I figure out how long I need my tubing?
And I could get 4 of these rod ends:
http://www.colemanracing.com/Rod-End...uty-P4337.aspx
But I think I still need the inner sleeve bushing things for them which I cant seem to find, but either way that means it'll probably cost around...$150 or so for a home made pair of rear LCA's.
This seems like an excellent idea, but I see why people dont do this all the time.
Thread
Thread Starter
Forum
Replies
Last Post
1Aauto
Sponsored Vendors
0
09-02-2015 01:35 PM
