92RS_Ttop

iTrader: (3)

This past winter I swapped out my V6 in favor of a 350. While I had everything out of the engine bay, I figured I'd upgrade/replace the worn out parts of the front suspension. I replaced all the bushings with poly, the balljoints, and control arm bolts with new parts. I also swapped my 30MM sway bar for a 34MM hollow bar and replaced the coil springs with good used ones from another member's Z28. The struts are KYB's and have less than 6k miles on them so I left them alone. I built my own wonderbar in '07 and it's holding up fine.

Hoping to balance the front upgrade, in the rear I replaced the sway bar bushings with poly and upgraded the bar from the stock 19MM to a 24MM bar I picked up on Ebay. I also swapped in a good used set of WS6 rear coil springs, also from another member here on TGO. Everything else in the rear is stock, including the shocks. They are not worn out or I would have replaced them as well.

I've noticed a few problems and I'm not sure what the best approach is to correct them.

#1 - The car used to be very neutral when it came to taking corners. No over/understeer and once in the corner it was very stable. Now the rear end feels like it wants to come around on me unless I take the corner very gently. I know the car is capable of more than what I am getting from it now, even accounting for the added weight in the front end from the bigger engine.

I have a 36MM sway bar and was thinking of swapping this in to correct the oversteer, but I've seen conflicting advice on this while searching the boards. I've also seen suggestions of upgrading the rear shocks, and I do plan on changing them out for KYB's this winter when I work on the rear end. I will also be replacing the bushings in and boxing or upgrading the LCA's and PHB.

#2 - I swapped out the original steering gear for a quick-ratio one I found at the U-Pull and added the steering cooler as my car didn't have one when I got it. I should probably mention that the PS pump is not original either, it is a U-Pull find as well since my original would not fit the V-belt setup I used on the 350. The steering wheel is now turned to about the 2 o'clock position when the wheels are straight ahead. I didn't think swapping the steering gear would affect the tilt of the wheel. If this is normal, I can fix the wheel easily enough. I just want to make sure this isn't an indication of something I messed up in the front end.

#3 - Also related to the steering gear swap I think. When I turn the steering wheel 45* left or right, I get a loud squeaking/squawking kind of sound from the front end. It only does it as the wheel passes through that 45*point. If I turn it less I get no noise, and I get no noise after that point until I hit the lock where I get the normal whining "that's as far as the wheel goes" noise. I'm wondering if I got a bad box?

#4 - The steering wheel is much harder to turn than the original one was. I did follow the adjustment procedure in my shop manual before I put it on and initially had it adjusted too tight and it was a real bitch to turn. I backed the top adjusting nut off a bit and that seemed to help. Its still tighter than my original box though. If I back it off any more I'm afraid it'll get too loose, but if I have it too tight will it damage the box or the pump?


If you're still with me after that novel, I'd appreciate any advice you guys have to give.

Oh, I should mention the car is not going to see a dragstrip or autocross event, but will be used hard stoplight-stoplight and on the twisty backroads around me.

1988-305-tbi

when you changed springs did the ride height chage at all? did the front drop?

that 34mm hollow bar is a little bit stiffer than the 30mm, but that 24mm is way stiffer than the 19mm, you need more front bar, put on that 36mm bar.

i have a loud growning noise coming from my front end since i swapped in the new steering box, i think the noise is coming from the idler arm.... power steering fluid got on it durring the install, so it may just need to be greased, i have never noticed steering effort change from tightning the box. mine always feel smother to turn after the adjustments.

as far as the wheel being off center i would guess that the steering shaft wasn't put on the input shaft of the box properly, did it my self once and it put the wheel at 2 O'clock

when i installed my new box and pump from AGR,i noticed that steering assist is almost zero at idle, doesn't really work untill 1,000 rpm,

91interceptorZ

iTrader: (3)

I've notice that sometimes people put too much rear spring pressure in....making the rear too stiff, and it can come around easier on you....here is a simple way to check...put you stock rear springs back in, and see how it rides...I bet you the little softer spring rate is a lot more forgiving than the WS-6 springs. Sometime stiffer is not always better.

92RS_Ttop

iTrader: (3)

I don't think the height dropped at all. At least not that I have noticed. Looking back at pics of the car before the swap, I don't see any noticeable difference in height.

The idler arm is brand new as of last summer, had to replace it to pass the inspection. No fluids or anything were spilled on it, and during the swap it spent most of its time on a shelf with the rest of the steering linkage.

I'll check the alignment of the steering shaft, but I always put it back on so the bolt is over the flat face of the input on the steering gear.

I have noticed that it seems to have almost no assist at low RPM. I wasn't sure if it was part of the box's design, or something to do with the increased fluid capacity from adding the cooler or the increased weight of the 350. I have to parallel park it on the street in front of my house every day so I noticed that right away. Kinda getting used to it now though.

92RS_Ttop

iTrader: (3)

I can try that, I still have the old springs. When planning this all out, I figured it would be best to have matching springs front and rear. Also, I forgot earlier that the front springs are not actual OEM Z28 springs, but the equivalent Moog replacements. I don't know if that makes a difference or not, but thought I would throw that out there.

I have the next couple days off, I'll try the springs and see if I can find the correct bushings for the 36MM bar and install it. I didn't put it on initially because I had trouble finding the bushings and when I bought the bar I had already installed the 34MM bar and I HATE changing that bar.

91interceptorZ

iTrader: (3)

I agree with 1988-305-tbi also on bigger front bar....but I road race my camaro and use stiffer front springs with stock spring rate rear springs and seems to work out good....at least that's an easy change and somewhere to start...

1988-305-tbi

the moog springs are much stiffer stock is like 550 and i think the moog are closer to 700, you should have and understeer condition if anything, i would try the 19mm bar again and see if it feels better, might be to much rear bar, i know mthat my car feels like the rear wants to skip over small bumps when theres too much rear bar,

92RS_Ttop

iTrader: (3)

I'll see if I still have the old rear bar bushings and try swapping that out first as its easier to do than the springs. If that doesn't correct it I'll try the springs. I think I'll save trying the bigger bar for last since I'd have to order the bushings and my upgrade budget is gone till next winter.

I'll post up the results after a road test.

92RS_Ttop

iTrader: (3)

I swapped the rear bar and took it for a drive. It's not oversteering anymore, just the opposite. Its understeering now, but its not quite as bad as the oversteer was. I'll try swapping the coil springs tomorrow and see what that does for it. I think right now a 22MM bar would be perfect on it, but I don't have one to try. If the coil springs don't help and the larger bar doesn't I know where I can get a 22MM bar to try.

I straightened out the steering wheel, I just repositioned it on the steering gear input shaft. The wheels were straight and the pitman arm was parallell to the frame rail so the box and linkage should be fine. Not sure why it doesn't line up the same as with my old box, guess its just the difference between the ratios.

Still getting the noise from the front end when I turn the wheel, and noticed something new tonight when I went to test drive it. Until I brought the revs up and pulled out, the steering was very jerky and twitchy when I turned the wheel. Almost felt like the power assist was rapidly cutting in and out. once I started driving and made a few turns it smoothed out to where it has been. I'm guessing there was just still some air in either the steering gear or the cooler pipe.

92RS_Ttop

iTrader: (3)

I don't think makes much of a difference, but I don't want to leave anything out either. When I swapped the original, smaller rear bar back in, I reused the old rubber bushings for the axle mounts and the same poly end links that were on the bigger bar. I did have poly all around on the bigger bar. Like I said, I don't think it would make much of a difference, but wanted to throw that out there just in case.

Swapping in the old springs and taking it for a test drive later today.

92RS_Ttop

iTrader: (3)

Just got back and its not understeering as bad as it was. I also put the bigger bar back in because I felt it would be too soft with the old springs and smaller bar. Its better than it was with just the smaller bar, but the old springs are too soft. The rear doesn't feel as planted to the road as it did with the stiffer springs. Its bouncing higher over bumps and feels like its trying to skip around turns, especially if there is a bump in the turn. A lot more body roll too. I'm gonna leave them in for now till I can get some bushings for the 36MM bar I have.

Can I use 34MM bushings with the 36MM bar, or should I get the 36MM bushings? I was also thinking of getting some new 34MM bushings and trying to open them up somehow to 36MM since they are a lot easier to find and a lot cheaper than the 36MM bushings I found so far. Any ideas on how to do that?

92RS_Ttop

iTrader: (3)

After swapping in the old springs, I did notice that the rear dropped about 1/2"-1" from where it was with the stiffer springs. Front still hasn't changed at all that I have noticed.

91interceptorZ

iTrader: (3)

If your bouncing rear bad in rear, or skipping....check you shocks....maybe a little too soft. You want the back to absorb some stuff....a little squishy per say....to controll the body roll try using different bushings....you will still have a little...the ride height should not have changed with different spring I would think...maybe I'm wrong...should be same ride height with different spring rate....
Are you having body roll in the rear, like squatting when you turn....or in front, like 'plowing' corner down....or is it the whole car body rolling on side??

92RS_Ttop

iTrader: (3)

The shocks are probably not original, but they are older. I plan on replacing them anyhow next winter as part of my work on the rear of the car. I want to upgrade to 3.73's with posi, clean and paint everything, box the LCA's and PHB(or replace) and hopefully upgrade to rear discs.

The rear is shifting over the bumps, its kinda hard to describe. Its almost like bump steer in a FWD car. The rear of the car is rolling more than the front, but the whole car overall is rolling more than with the stiffer springs. I have poly end links and axle mount bushings with the larger bar, poly end links and rubber axle mount bushings with the smaller bar.

I don't get the feeling that the rear is going to break loose like I did initially with the new springs and larger bar. Its hard to describe how it feels in the corners. The best I can do is to say the the front feels like it can handle more turn than the rear. The rear feels like its following the front but only because they are attached to the same car. Kinda like the front is pulling the rear through the turn, not like they are working together like they should. The difference from front to rear feels almost like driving 2 different cars at the same time.

Last summer the car would feel like it settled into the turns. It would give me a little bit of roll, then no more and it was almost like it was saying "Ok, we're in the turn, I can do this no problem." I could feel the point at which it hit its peak in the turn and it didn't feel loose or twitchy like it has this year.

Flip 2

iTrader: (1)

KYB rear shocks are pretty cheap, you might want to try them.
Get some poly bushings for the 36, it should make you happy.
With the 24 rear bar, that should move you ahead.
PS- the KYB Gas-adjusts may be stiff enough themselves, so the softer stock springs work for you.... I assume you have the GR2s on front.
Good Luck, the car will be nice.

91interceptorZ

iTrader: (3)

If your shifting in the rear...you probably need to upgrade the pan hard bar....the stock ones flex and the rubber bushing give a lot....

92RS_Ttop

iTrader: (3)

Yeah, the Gas-A-Justs are what I'm planning on getting. I don't have the $$ for Koni's or Bilsteins. You're right, I do have the GR2's on the front. I get paid in a couple days and I'll be ordering the bushings for the 36 bar then.

92RS_Ttop

iTrader: (3)

Panhard bar is original, and the bushings probably are too so that makes sense. I haven't decided if I want to try boxing it or making my own yet.

RED_DRAGON_85

gas-a-just shocks are pretty good, and transformed my ride in my caprice from literally "a boat in a thunderstorm" to what feels somewhat like a normal car.

if it were me, id pay the little extra for AGX shocks and struts because they are adjustable.
you will be able to play with the stiffness to get the feel you want in the corners.
its not as simple as "stiffer is better/worse"

without getting into too much detail, a turn can be divided into 3 parts:
entry, steady cornering, and exit.

on entry, you want the outside rear tire to compress (roll) faster than the front outer tire so that you will have a bit of understeer.
if your compression is too much faster though, your rebound will be thrown off and the car will oversteer on exit.

on exit, you want the front and rear outer side to come up at the same rate and force so that you dont have any nasty suprises if you hit a bump.

in steady state cornering, your springs and swaybars will tune your ride.
on exit and entry, your shocks almost have more effect than springs and swaybars due to the "instantaneous" nature of what is going on.

RED_DRAGON_85

also, you will want to either get a panhard rod with some kind of spherical bushing (spohn polyball will be great here, so will johnny joints or regular spherical bearings, you choose)

the reason is that the phb is one place where absolutely zero deflection is considered ideal.
some places you want a little deflection, but others you dont.
i would stay away from poly bushings in the LCA's for example in favor of either rubber or spherical bushings.
motor mounts are another place where deflection is good.
PHB though, go for an aftermarket bar that will give you some adjustment and less deflection

92RS_Ttop

iTrader: (3)

Yeah, I've heard about the problem with poly in the LCA's. If I don't box the ones I have and use rubber bushings, I'll probably fab my own with rod ends on one end and bushings on the other. As far as the PHB, I haven't really been looking at the adjustable ones since I don't plan on lowering the car. I Will probably go with rod ends on both ends of that if I fab my own. I doubt either way I'll buy ones from somewhere unless I am running out of time or I get them for almost free. Nothing against any of the site sponsors or parts stores or anything, I've just always preferred to make my own stuff when I can.

1988-305-tbi

as far as the rear shifting over bumps, it the panhard the geometry has changed and the panhard isn't level which will cause the rear to feel loose on sudden lane chages or when you hit a bump during a corner, the panhard bar should be higher on the chasis side than the axle side, if its lower the car wil handle and corner like crap

it takes a while to properly bleed the power steering system, if you don't due it right air will stay in the box and cause intermittent steering effort, this happened on the first 2 boxes i installed

RED_DRAGON_85

it will handle poorly but not due to the PHB letting the car "shift" through a turn.

the amount of left-right travel is less than 1/16 of an inch, so unless you are super sensitive, thats not what you are feeling.
what you are feeling is that the front is rolling differently than the rear.

1988-305-tbi

i am very sensitive, thats how i know what i'm feeling, i can tell 1-2lbs o air pressure per tire or 100lbs of weight being added to the car, if the panhard is too low, during a left hand turn if i hit a bump the rear will lift,t he front will squat and side to side movment will make the car feel like the rear is held on with rubber bands as it first pivots left than right, before it settles down, if you understand how the geometry effects our rear suspensions you will understand what i mean

Guest

I just read this whole thread and must say you need to back WAY up. You guys are getting into things that are trying to bandaid an unfixable problem- at least to the extent he has without major expensive shock valving...WHICH AIN"T NO AGX TOKICO...nor a Koni yellow either.

Your first clue to your problem is the stock Z28 front spring and the ws6 rear spring.

Guys, there is the problem, anything else you touch is a bandaid fix and not to the rrot of the real problem...his roll axis is is terrible.

get sme WS6 springs for the front also so as to balance the car and not have the front compressing while the rear jacks so high in the inclination of the dynamic roll axis under braking and corner entrance.

sorry guys, ain't no larger swaybar gonna fix this one, nor panhard bushings, nor shock upgrade.

Dean

92RS_Ttop

iTrader: (3)

I thought the z28/ws6 used the same components, just different RPO's depending on whether it was a camaro or firebird? Are you saying the spring rates are different between the 2 packages? When researching what parts would be needed for this upgrade, I didn't see anything on here or any of the parts stores I searched or summit that mentioned any differences between the 2 sets of springs. The part numbers are all the same whether I search for a Firebird or a Camaro.

Looking back through my parts records, I have them listed as "Formula Rear Coil Springs" so they may not be ws6 springs if there is a difference between the Formula and ws6 handling packages.

I agree the panhard bushings are probably not the problem and the rear end itself isn't shifting over bumps in turns, its the whole rear of the car being bounced up and the motion of the turn is swinging the car outwards until it settles back down. I don't think its actually going airborne, but that is the feeling of it. With the stiffer springs on it, I didn't have that feeling. I could feel the bumps, but it felt more like a slight tap on the rear than a bump.

If there is a difference between the z28 and ws6 springs, which are better? I'd really rather change out the rear springs than the front, they are so much easier to do.

91interceptorZ

iTrader: (3)

hey there.....
not going to argue with you on this one...I agree.....but I think he has all z28 springs in there now ....about half way down post, I suggest z28 springs back in cars rear end....he said he put them back in already, I may have missed something here....did he put ws6 springs back in...thought were talking about z28 rear springs....so car should be more balanced...said it lowered rear back down level so it's not raked.... then we suggest other items based on his desriptions.......

92RS_Ttop

iTrader: (3)

Sorry, that's mostly my fault for the confusion.

I have 2 sets of rear springs for the car. The original springs are RS springs, NOT Z28 springs. The new ones I purchased on here which are the Formula/WS6 springs.

Remember, the car was originally a V6. It had the FE1 "soft ride" suspension in it.

The front springs I put in are Z28 springs, that's probably where the confusion is coming from.

The rear went up about 1/2"-1" when I put the new springs in. I didn't even notice it until I put the original springs back in and noticed it was lower.

Guest

I do realise he put the z28 spring in the back- I said I read the entire post. He states in doing so he is getting body roll and later states the car is 1 to 1/2" inches lower with those second springs as opposed to the stiiffer 1st ones (The WS6 ones)
1) His roll center is lower- greater leverage on springs
2) his spring rate is lower also- multipliying a decrease probably by 4 now.
Conculsion- I bet big money he is bouncing off the bumpstops the way he discribes how the rear now bobbles through a turn andit feels like two different cars in one- the back is hitting off the bumpstops and not making sense to him(it might now since he knows this)

Anyways, going back to what I wrote above, I will reitterate that he puts the ws6 rears back in (Or what ever the stiffer ones are he has- he says the rear feels better with them, it was just tail happy) and get some fronts that are higher in rate that match the rear in proprtion and do not hit the bumpstops in roll or chassis set laterally.

then he can play with swaybars to fine tune the chassis

ws6 and z28 spring rates? I have no idea other than I have always heard the WS6 springs are the highest rate you can buy in factory springs. They were made for the heavier cars. WS6 spprings are still not a race car catagory spring by any standards unless the car is stripped of body roll weight. These cars are heavy up top with the rear glass,etc, its why they need big swaybars.

Personally, I do not think anyone here is sure what springs he has to be exact and or the condition they are in. It sounds like he might have rates conpatable but heights that are wrong rendering a bad roll axis. I have no idea where his desired ride height is but I do know from his post the rear with stiffer springs sits higher and the rear with the softer springs sits lower...so..if he likes the lower ride hight but the stiffer rear springs, maybe just first try and cut the rear spring to lower the rear that 1 1/2" lowering the rear roll center and thus the roll couple. If the very slight stiffening of the cut makes the roll rate still too stiff then go down to the 19mm rear bar.

Now if you do not want to cut the rear springs to lower the roll couple, then the front needs to be stiffer- hence why I go back to my original assuption of him getting stiffer front springs. I thought my posting would be clear I knew he had the softer rears in by when I said he needs to get WS6 fronts to match the WS6 rears- I just tried to saty it in fewer words- but now there is the novel

Guest

The problem with doing tech like this and coming inbto an already running thread is that most often we are why ahead of ourselves in chassis setup.

I should probably do a long novel post on initail chassis setup but the problem with that is that what it takes to make one of these cars handle they do not adjustment provision on them from the factory and it takes ALOT of work and knowhow to weven get the chassis set at best ride height WITH the best spring rates FOR the componants you are adding AND the chassis weight, engine weight and size, chassis bias, rearend carrier, etc........BUT..

It all boils down to initial chassis 101 that is optimum chassis geometry and stance. What chassis heights are best? That can change with a simple tire circumfrence difference. Not everyone here runs the same height and circumference tire.

What was never asked on this post before I got here? Do you have a picture of the car, or measurements, or tire sizes,etc etc etc. We are just giving ideas up and down in the loose-tight spectrum so he can play wih things rather than going back to basics with balanced front and rear spring rates for that chassis. Generally when we are talking about stock springs whether they are RS, Z28, WS6, Formula, IROC whatever, for the m,ost part on their correct casr they "ARE FINE WITH THEIR INTENDED WEIGHT BIAS AAND OPTION PACKAGES on the car pertaining to weight distribution. WS6 springs are factory engineered for the that car and the bars fine tuine it to slighlly push from the factory. An RS is set with RS springs and fine tuned with bars to slightly push from the factory...and so on. Not all the cars are the same weights and options- SO you start putting WS6 rears and Z28 fronts and god knows whatever bars onto an RS and you have mismatched ride heights and rates and weights pertaining to the chassis dynamics. Then trow in factorys like different shocks and condition of those shocks, different tires and the condition of those tires, etc etc etc and we are fighting loosing battles in suggesting helpful options.

thats why I said originally to back way up and get matching springs- its our best guess to adjust an RS car to other factoiry springs(at least they would match even if they are not designed for that car) and then later we get imput on changing bars to fine tune that chassis in lateral balance at steady state.

92RS_Ttop

iTrader: (3)

Vetruck - I for one appreciate the novel. I think I have a fair grasp of what is going on and needs to be done to correct the problems, I was initially looking for confirmation that I was correct. I have no problems with learning new things either.

Basically, I am looking for now to get the car to be stable and safe in turns. I was trying to emulate the stock Z28/WS6/IROC setup as best as possible for now. I do plan to add things like subframe connectors at some point and will be replacing the wear items in the rear suspension this winter. It all started because I didn't want to drop a 350 on top of the old, worn out V6 springs. If it will help that much, I can grab the specifics on the car when I go to lunch shortly.

As for the springs themselves, they appear to be in good shape. According to the sellers (I know, I know) the front springs I bought have about 5k on them, the rear ws6/formula springs have 50-60k on them. My original rear springs have 105k on them. I have tried to describe them as best I can, but I don't have the equipment to measure the actual rates of them.

With the original(softer) springs in the rear, yes, the rear is hitting the bump stops. If it's not, its very close to hitting them. The exhaust tends to swing around over the axle and hit the body so I can't always tell which one the "thunk" in the back is coming from. If it is hitting the bumpstops, its not hitting very hard.

As for ride height, I would prefer to keep it stock height. The roads I drive everyday are typical of PA roads(meaning they suck and have huge holes) and I need as much clearance underneath as I can get. And the height difference is 1/2" to 1", not 1 1/2". Not sure if that was a typo or not, but wanted to make sure we're on the same page. Cutting the springs doesn't bother me at all. Since the stiffer ones are off the car right now anyhow, it won't be hard to do. Any recommendations on how much to cut, or should I just start with 1/2 coil, check the height and go from there?

Since the softer ones are the original springs with 105K+ on them, I suppose its possible they are just sagging and the increase in height would come even if I replaced them with OEM V6 springs?

I appreciate the input, and believe me I know how hard it is to troubleshoot a problem when you're not there. I do Internet and VOIP technical support over the phone for a living.

92RS_Ttop

iTrader: (3)

The car was originally a plain 92 RS with the 3.1 and T5. 15" wheels with 215/65/15 tires with A/C and T-tops. Stock FE1 suspension. Only thing I added was the KYB GR2's(roughly 5K when installed, about 8K now) in the front and I built and installed a wonderbar.

As it sits now, it has a carbed 350/T5 with just power steering and alternator. All A/C stuff has been removed as well as all the emissions stuff. Z28 springs in front with 34MM bar, all poly bushings in front except for motor mounts and new balljoints. Also switched to the quick ratio steering gear. Rear has the 24MM bar with poly bushings and the OEM V6 springs. OEM shocks in back, unknown age, front has the KYB GR2's. Still has the 15" rims on and I plan on keeping them. Once these tires wear out, I'd like to replace them with some 225/65/15's or possible 235/65/15's if I can get them to fit the rim/fenderwell.

Also removed are the spare tire/jack from the back and all the sensor/smog wiring from the front that wasn't needed to run the carbed 350 as well as the rubber coil spring isolators from the front coil springs. I don't know if they will affect the ride height or not, but they were so squished from 17+ years on the road that I couldn't justify putting them back in.