Suspension / ChassisQuestions about your suspension? Need chassis advice?
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Was wondering if i could get some help... Tryin to find the best deal on a setup like this....
Need some input on where i could find this setup (but for stock springs) up for a descent price... N minus the spindles... I know Racecraft/Spohn/Hawks, has stuff similar... I just need to know of peoples experiences with the different companies/products, N where i could get the most bang for my buck... I just dont wanna order every single piece from 10 different sites... So let me know.. Thanks...
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It looks like that kit is for use with stock springs, or available that way, at least on the passenger side... .
Its not one side stock the other coil over... Their just showin both options... The other thing i dont know is this... Does power have any effect on it.... Forgive my lack of knowledge.... But as far as switchin from gear box to rack n pinion... Will horse power effect that change in anyway... Im assuming it doesnt.... But i figured id ask..
__________________ if it aint broke..then break it and fix it...how else you gonna learn.
But as far as switchin from gear box to rack n pinion... Will horse power effect that change in anyway... Im assuming it doesnt.... But i figured id ask..
I'm not sure about what you're asking... but increased horsepower will not effect a power steering pump (RPM's will though). Engine swaps will always be easier with manual steering, even if you still use a steering box.
but increased horsepower will not effect a power steering pump (RPM's will though)
Thats the little things i was askin about... Y would RPM's effect it? I figured id just get a rack n pinion setup... Then i wouldn't need a gear box..Right?
__________________ if it aint broke..then break it and fix it...how else you gonna learn.
That is correct, no gear box or power steering pump is needed with a manual rack.
You can prevent any RPM associated problems with power steering with an underdrive pulley. Instead of me explaining it: "The second noise is caused by cavitation. As you increase pump speed, more and more fluid is forced through the ports per unit time. There comes a velocity where the fluid just doesn't want to move that fast, and the vanes inside the pump will cause a vacuum, which is instantly filled with oil vapor. When the vane reaches the high pressure port, this vacuum cell is opened into a high pressure cell, and oil rushes to fill the void. A little 'sonic boom' results. These individual 'booms' are virtually microscopic, but they add up. What they translate into is a sound that sounds suspiciously like a whine. Now every pump cavitates. It's in the nature of moving fluid. By smoothing the radius of the ports, and relocating supercharge holes (I'm not going into that), engineers can reduce cavitation or push the frequency spectrum of the whine to a less noticable frequency. It is, in fact, where the bulk of pump engineering hours are spent.
Anyway, that funny high pitched whining that Mike Martin is hearing after his autocross run is the third type of noise. This type of whine is from the oil being aerated. When the pump is really screaming, the oil in the resivoir really gets churned up. This allows the occasional air bubble to pass into the pump, where it is totally pulverised into smaller bubbles. Eventually, the oil gets enough of these bubbles in it that you begin to hear it. If you want to really experience aeration, just run your pump low on oil!" -from: http://www.thirdgen.org/noises-power-steering-pump
Wow... Thats crazy... I think my brain started to aerate just trying to read that (LOL)... Thanks for the explanation though... I figure doin a rack and pinion vs a pump and box will save me weight... right? Is there a disadvantage to having a setup like this... more so with a higher horsepower engine vs a 2-300 HP one? Kinda off topic, but i figured id ask. Plus i wouldn't need a PS pump/Gear box/ or a kit like this... Right?
If thats the case then i figure both setups would cost about the same, but R n P would be less of a hassle. Is there a disadvantage to Rack and Pinion???
Last edited by weaz4200; 10-09-2009 at 02:06 PM.
Reason: add pic (reference)
A manual rack will save you at least 25-30lbs, and you won't be losing any power turning a power steering pump. But, steering effort will be increased, steering ratio will decrease, and your turning radius will increase.
That is correct, with manual rack and pinion, you won't need a gearbox, PS pump, or a kit like that ^^
Steering effort will be increased, steering ratio will decrease, and your turning radius will increase.
Like power brakes, right? So basically no gear box and running a rack will be like getting rid of the brake booster, hence more effort to brake the car. So whats the benefit of this setup? Other than less weight.
Like power brakes, right? So basically no gear box and running a rack will be like getting rid of the brake booster, hence more effort to brake the car. So whats the benefit of this setup? Other than less weight.
less weight is the only benefit. And the brake booster has nothing to do with steering. THe other thing is this setup is 3.75 turns lock to lock, thats a very slow ratio, not the best idea for steer driving.
And the brake booster has nothing to do with steering.
Thats not what i was sayin... I was trying to compare the 2... Like GREGSZ-28 said...
Quote:
steering effort will be increased, steering ratio will decrease, and your turning radius will increase.
What i was sayin is.... That switchin over to a rack setup from PS/gearbox is the same general outcome as switchin from a brake booster to no booster... Be it the steering or the brakes.... goin to those setups will change the control... Like no booster will mean that i will have to push the brake pedal in more...hence not as easy to brake. As with a rack vs a gearbox, with a box turning is a lot less revolution than having the rack setup which will result in me turning the wheel more to get the same outcome if i had the box... Thats what i meant... N e ways.... back to what i was askin... Where i could get the setup i initially asked about for a decent and lower price...If possible.
__________________ if it aint broke..then break it and fix it...how else you gonna learn.
You can go to manual rack & pinion or power rack & pinion. Just like power or manual brakes.
Really.. did not know that.. So how would that setup look like... Where can i get that? I didnt see a power R n P on Spohns site... Unless i didnt see it...
I don't know of any bolt-in power R&P kits. You'd be lucky to save 15 lbs with power R&P. You could save more than twice that weight by buying aluminum heads, gain a little power too, and it would cost much less.
15 lbs? How heavy is the stock steering box? I have a billet appleton rack, which is what was used in one of those 3rd gen R&P conversions i saw here, that rack weighs next to nothing compared to the box and centerlink.
Maybe i shoulda been more detailed as to what im starting with... Nothing... I am not going to use any of the parts i originally took off the car...
Quote:
I don't know of any bolt-in power R&P kits
If i get a tubular k-member like spohns or n e of the other ones out there it should come with the brackets to mount the R & P... Unless im missin something.
Quote:
So swap for an aluminium KRC pump & bracket, they are lightweight.
I could do that... But i wouldnt need it without a Gearbox would I? Also what different between the manual rack & pinion or power rack & pinion???
If you have any type of power steering, with a gearbox or R&P, you need a power steering pump.
So i get a R & P setup and a PS pump... So again i ask... What does a power R & P setup consist of... A PS pump and R & P... Who sells a Power R & P????
__________________ if it aint broke..then break it and fix it...how else you gonna learn.
The manual rack on the spohn site is a ford pinto rack.
if you look around, you should be able to find a power pinto rack.
the other option is to use a 4th gen power rack and use a k-member that will accept a 4th gen rack.
unisteer has power racks
but seriously, do some research on your own.
its more fun and rewarding to figure things out by yourself for a change.
as for my opinion?
if you get a power rack or a manual rack, your turning radius will be increased unless you get modified spindles or you buy racecraft spindles built for rack and pinion.
there is no way around this.
you can have yours shortened by a machine shop for a competitive price i am sure.
next, cost.
starting from scratch, it might be a little bit more worth it, but a power rack-n-pinion setup is big money.
if you want it, do it!
just realize it will be expensive.
a manual rack kit will be cheaper, but as already said, you will have a higher ratio steering setup than your RS box, which is enough to turn me away...
you probably wont notice it driving down the road, but if you are in to driving in the mountains or on twisty roads ect, you definitely will.
if it were my car and your money, i'd have a power r-n-p kit with 2" drop spindles with modified arms. i'd keep my spring boxes so i wouldnt use coilovers, and i would call it a day. the main advantage of a rack and pinion steering setup is NOT reduced weight, but better steering feel and reduced complexity.
look at the kit and what it consists of.
compare the two or three parts to the ten or so linkages in a traditional steering box... big difference.
__________________
Last edited by RED_DRAGON_85; 10-10-2009 at 07:48 AM.
Do some research on your own.
its more fun and rewarding to figure things out by yourself for a change.
Red_Dragon_85... Im all about researchin things myself.... But consider this... I dont know exactly what to look for... As this is my first build... I have little knowledge.
Quote:
i'd have a power r-n-p kit with 2" drop spindles with modified arms. i'd keep my spring boxes so i wouldnt use coilovers, and i would call it a day.
Its things like this statement that i have yet to learn... Thats really y im here, not just to ask what to do and where to get it... but to learn this type of stuff as well as find out whos done it and what they think. So if you'd be so kind as to elaborate a little on a few things so that i could learn how things work, id appreciate it... So first... Y 2" drop spindles... N y Modified arms... u mean a-arms?
Quote:
better steering feel and reduced complexity.
What exactly do u mean by better steering feel??? thanks... The other thing is... So say 2" drop spindles.. i have yet to learn parts that are interchangable... Like would i need to look for them for an 82-92 camaro.. or would different years work?
By 'modified arms', he mean having the steering arms on the spindles shortened to maintain a tighter turning radius, and to increase the steering ratio.
Thanks.. will definitely read that.... n e other threads you could post links to that can teach me a few things so as i could see what my options are.... U know with different setups... That way like Red_Dragon_85 said... I could do the research and learn in the process... Also... u said...
Quote:
there'd be a 2" drop and the steering arms on the spindles are shortened to maintain a tighter turning radius...
What if i dont want it lowered, do they have regular height spindles with just the steering arms shortened???
__________________ if it aint broke..then break it and fix it...how else you gonna learn.
What if i dont want it lowered, do they have regular height spindles with just the steering arms shortened???
Not that I know of. IIRC the racecraft spindles are the only aftermarket spindles for third gens, and they are 2" drop from stock height and have stock length steering arms. Basically, if you want shortened steering arms, you need to have it custom done.
your turning radius will be increased unless you get modified spindles or you buy racecraft spindles built for rack and pinion.
So if i go with a rack and pinion with stock spindles the radius will increase, but getting a 2" drop spindle which has the same length steering arm will basically offset the turning radius??? I dont get it.... Y?
__________________ if it aint broke..then break it and fix it...how else you gonna learn.
What intention of use is the car being modified for?
Daily driver?
AutoX? full time, part time
Drag car? full time, part time
Weekend cruiser/ garage queen?
Show car?
please give me % of the above useage and I will give you my opinion. Sounds like money is not a real issue(for the most part) you want things done right. So we need to hear what the intensions of the build are first in order to really answer your questions.
So the 2" drop will lower the car 2"???? I just dont wanna bottom out the car... Even though it does look pretty mean...
Daily driver?
NO
AutoX? full time, part time
NO
Drag car? full time, part time
15%
Weekend cruiser/ garage queen?
50%
Show car?
35%
Its kinda hard to really know as far as drag... I do know that with as much power as i want, i definitely wanna utilize it... Just dont wanna F something up... My pockets aren't that deep... As this is my first build.. I wanna learn how things work as well, not just build it and be done. It wont be driven other than the summer and spring/fall when its not raining. No winter what so ever... Unless the garage is on fire and i gotta save her. Plus i was also thinking of converting to manual trans... I got a lot ideas... Just hoping i will actually get it put back together...
I wish there were guys like you guys in my neighborhood... The stuff thats involved with cars is insane.... Wish i woulda paid attention in geometry class... Vetruck... Nice thread man (bout the suspension)... I wish i understood half of what ur sayin... Wish i had got into cars earlier, woulda know a lot more by know, had i done that... thanks for the help so far.
look at it this way...
if the rack can move the steering arm 2" of travel and thats it, you want shorter arms to get the most steering you can.
ill try and explain it this way...
the spindle rotates on the axis A-A that i drew (more or less)
the rack end attaches to B
the wheel mounts to C (basically)
when you turn the wheel, the pinion gear moves the rack inside the housing and the end result is that the ends of the rack will move a certain distance... lets assume 3" from center to maximum.
now, knowing that the rack attaches to B, we can see that if the distance from b to the axis (the green line) is longer, you will get more leverage, but less angle. think of it like using a wrench.
you are trying to loosen a sparkplug and the end of the wrench can only move up and down two inches... you want a short wrench so you can get the most "spin" on the sparkplug...
anyway, the wheel attaches to point C
normally, C is lower on the spindle but in the racecraft spindle the spindle has been moved up two inches, shown by the blue line, giving a drop in front end height.
what does this all mean?
if you want rack and pinion, you will either need modified spindles, or rack and pinion spindles.
to have your spindles modified is a simple procedure that any and i mean ANY competent machine shop can do for a lot less than $550. the racecraft spindles are used specifically if you want a lower car AND a rack and pinion
for most people, this is a good idea because it lets you use stock springs but still get a lower car.
you can even use spacers to get the car higher up if you really want, but dont go crazy with this
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Last edited by RED_DRAGON_85; 10-11-2009 at 05:56 PM.
I get it i think.... So as far as steering goes the drop has nothing to do with it, its more so based on the length of the arm... With a longer arm you could turn an 1" but with a shorter arm u get double that or more... but what i dont get is why when switching over to a rack i lose the turning radius?
__________________ if it aint broke..then break it and fix it...how else you gonna learn.
what does this all mean?
if you want rack and pinion, you will either need modified spindles, or rack and pinion spindles.
to have your spindles modified is a simple procedure that any and i mean ANY competent machine shop can do for a lot less than $550.
Care to explain how this is done & what to ask for?
I'm not looking to switch, but others might find the information useful.
Care to explain how this is done & what to ask for?
I'm not looking to switch, but others might find the information useful.
what needs explaining?
take your spindles to a machine shop.
tell them to shorten the arms by 2" 3" 1.5", whatever floats your boat, ect...
they will cut the arms off at the bolt holes, cut however much off you want, then re-weld them together...
pretty basic
you can do some simple geometry and it will be easy to figure out how much you need to shorten the arms for the same max steering angle.
if it were me, i'd set up a simple proportional formula
as for the rack having less turning radius, its just an inherent part of a rack and pinion system.
a typical steering box turns a set amount of degrees which goes directly to the wheels via a bunch of linkages
a rack and pinion system moves a linear distance to get the steering.
its nothing wrong with the rack.
... but what i dont get is why when switching over to a rack i lose the turning radius?
Back to geometry. The stock steering box attaches to a pitman arm of some length...so when that swings left and right it will have lets say 3" each eay of swing.
The rack comes out the side and protrudes so to speak. No leverage arm that has length. Thus, the rack only protudes left and right 2"
each way.
Shortening the spindle steering arms is the recieving end of the geometry which will increase the overall turn radius.
Its like gear ratio's- you have a DRIVE gear and a DRIVEN gear. Increase the drive gear or decrease the drivien gear increases the speed (or in this case throw). The steering box or Rack is like the drive gear, and the spindle steering arm is like the driven gear. Its the lengths each travel in relation to the other.
Keeping the stcok spindles may not be so bad an idea for you. A drag car does not need as quick a steering radius nor do you want twichyness. You want a little more straight line stability so a decrease in steering ratio would not hurt you here.
However, for a weekend crusier you may still be needing to u-turn, but not alot like you would in a daily driver in supermarket parkinglots. You will need to 3pt turn a u-turn in an intersection, but with a manual rack with increased ratio you will have troubled effort turning u-turns not power assisted.
I personally would just try it first, if not then later pull it back down and have them altered shorter.
if you are going to lower the car via drop spindles, just get the shorter ones since they are the same price as the longer ones.
If it were me? I would take the suggestion of a power rack with shorter drop spindles, but that is at the cost of $$$$, and I am more into handling and steering perciseness. In other words though, I would keep the stock heavy duty kmember for handling lateral g's- unlike what you seek for your choice of build. Kmemebers are great for weight savings on a drag car. Good choice.
i disagree.
a car that is no fun to drive because it sucks to turn is no fun at all!
true story:
my girlfriend has a 2003 v6 mustang and the steering is noticeably slower than my camaro IROC.
its no fun to drive it fast because of this...
haha
Hey Vetruck... can u explain this insert from ur thread with pics a little... This is all new to me, and i all about learning this stuff... Though I dont fully understand...
Quote:
RIDE HEIGHT will be based on 3" of travel MAXIMUM. So with Racecraft spindles installed, we want the stagnant chassis height to be "non argueably" set by the front A-arm ear height off the ground to be 1 1/2" higher than the centerline of the balljoint swiivel. This will allow for articlulation 1 1/2" up and down from centerline A-arm length- Spring rate used will ultimately be adjusted so roll in a corner yeilds about 3* and the outside compression travel at that max lateral grip be about 2" without bumpsteer (in other words- on a smooth asphalt surface)
I'd like to understand this before i move on with reading ur thread... So ive read on further and im just confusing myself... I kinda get the concept about the cars CG... but not really...Plus, i more so dont understand the numbers and/or calculations.... Think i might print out the whole thread and take it to school (in the next few days)... Im gonna have suspension class in a few months, but i doubt they'll get this in depth... at least im assuming they wont...Plus id like to get started on the front end..... If u wanna try and explain it a little more im all for it... Thanks for the help so far.
__________________ if it aint broke..then break it and fix it...how else you gonna learn.
Last edited by weaz4200; 10-11-2009 at 11:04 PM.
Reason: add info
I will steal this graph I put on that thread earlier and I rewrote it specifically as an A-arm with the values you quoted me from that post.
-red= A-arm
-blue= balljoint
-gray= spindle
-yellow= strut
-black dot with orange circle= chassis mount point/pivot point of A-arm.
The first of three show the A-arm parallel to the ground. This represents the longest lateral measurement of the A-arm span in articulation. Represented by the thick black arrow at bottom. now compare the next two lateral measurements (black arrows at bottom of each graph)
The center example shows the thick red starting point of the a-arm. 1 1/2" lower on the balljoint side than the chassis pivot. In max articulation, the A-arm will travel 3" MAXIMUM, but a normal travel of 1 1/2" - 2" range. We really ultimately want the spring rate to allow the car to set 1 1/2" compressed to level in a hard set corner (without hitting road imperfections) and allowing for about 3* of body roll. This is your camber curve or camber gain. It alows for camber to increase negatively as the body rolls and produces positive camber. In other words, lets say you start with -0.5 stagnant. Then in a corner with 3* body roll you would have +2.5 camber- however, witrh the A-arm camber curve you gain -4* camber in that 1 1/2" travel so at full set you are now at a combined total of -1.5* camber in lateral grip.
Example 3 shows bad camber loss all the way though articulation.
Example 2 shows gain then loss in extreme travel-however, usually in extreme travel no more body roll is present, only the tire is lifting quickly over a bump in the middle of the corner. the last extreme 1 1/2" travel does not in my book require camber gains if the chassis is set up with the proper travel limit through spring rate choice (spring rate choice depends individually on each car and weights)
REd... What does she have??? What do u have???? Setup wise?
haha, i was mostly kidding about that to make a point, but her car is a base model V6 mustang. its got the "comfort" springs, slow steering box for easy low steering effort, small roll bars so the car doesnt feel harsh over potholes ect...
my camaro has the Z28 suspension package with stiffer springs shocks ect.
ive also got a fast ratio steering box that makes a big difference in steering effort, but is a lot more fun. the other thing is i have a 11"-12" grant steering wheel.
a small steering wheel will make the steering ratio FEEL faster because of the fact that a smaller linear input will translate into a greater steering angle.
VETRUCK
one thing i have always heard is that the ideal angle for an a arm is parallel to the ground.
is this only in a non strut type suspension?
VETRUCK
one thing i have always heard is that the ideal angle for an a arm is parallel to the ground.
is this only in a non strut type suspension?
Yeah, I know this isn't directed at me, but I'll try anyways. With double A-arm suspension, due to the upper A-arm being shorter, you will always have camber gain throughout the range of suspension travel, regardless of lower A-arm starting point, unlike ours, that occurs only before the A-arms are parallel to the ground.
so with a strut suspension you want the arms angled down?
at ride height mine are parallel.
what this says is that i need drop spindles with longer springs to lower the ball joint by 2".
this would also raise the roll center though...
AGH!
So i gots another question.. So say i go with the 2" drop spindle for the front, i'll then still use a stock length spring...Right? So to keep the cars height even id put 2" lowering springs in the back? Does that sound right?
__________________ if it aint broke..then break it and fix it...how else you gonna learn.
Weaz, I hope this helps you, I have an 86 Iroc, I used a Racecraft K-member, A-arms, dropped spindles shorten for rack, bump steer kit, unisteer rack and pinion, Moog 5662 springs in front. PA racing steering shaft kit. I used a 28" tall Mickey Thompson up front. Car handles great, I have no less steering radius than I did factory, and have had zero problems with bottoming out or my lower spoiler hitting anything. I also used Koni yellows, Spohn sway bar and adjustable wonder bar, J and M stut mounts and Edlebrock 3 point strut brace.
In fact I can guarantee that the car handles better now than it ever did factory, and I love the look of the stance of the car. The car goes around corners with no body roll. My car is 100% street car, it is not a daily driver but very enjoyable to drive
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