Kennerz

Suspension experts,

I need some help,

I have the eibach pro-kit , bilstien HD's in front, and sports in the back. the factory 23mm rear sway bar and the 1LE 36mm front.

sub frames, wonder bar, stb, iroc G92 bushings, PHB, sphon spehrical bearing steel strut mounts, prothane trans mount
.

anyhow-
the car handles pretty good with the current set up ( just added the shocks and springs)

The car seems to understeer a little with the stiff front springs and heavy 36mm sway bar. Should I put back the stock iroc 34mm sway, or should I put a smaller rear sway bar in to compensate for the added front stiffness? or both a smaller front and rear to bring back some of the handling balance I had before the "upgrade" . as it is the rear is planted in turns, the front will push slightly, which is unerving at higher speeds. I also have 255s in front and 285s in the rear , does this add to the problem? With my current set up I couldn't get a 9" or9.5" wheel only 8" or 10" increments otherwise I would have used a 275 on the front.


What do you guys recommend I can do to restore solid handling balance, (more front end bite) I'll admit I haven't played with tire pressure much yet.

any help is appreciated

CrazyHawaiian

Well I'm no expert but generally speaking a bigger front bar will give more understeer and a bigger rear bar will give more oversteer. So if you did the big front bar then that can help explain the understeering feeling you get. To balance it back out you can either install a bigger rear bar or put the stock one back on the front. Other things that might be affecting you are the difference in front struts and rear shocks (if I read that right you have HD's in front and Sports in rear) and also possibly the tire pressures.

Souseless

The bars are not likely the source of your problem. That bar combo is more likely to cause oversteer. I would try tire pressure first. Did you get the car aligned after the spring change? Why did you use shocks that are not a match for the struts?

obeymybird

iTrader: (4)

i have the same problem going on with my car with the pro kit i still have a factory style strut and shock combo car handled great till i had the eibachs put on and i had it aligned i was thinking about getting the kyb adjustables or the bilstiens but know im thinking about going back to my stock springs again

Kennerz

everything was aligned immediately after the install. arround 5 deg caster, and .75 deg neg camber - I think 1/16 of toe in.


Bilstien recoomends using the HD front , and sport rear for a lowered car - that shouldn't be the issue.

I'm thinking with the stiffer shocks and springs , now the 36mm could be too much front bar.


Help me out, I thought a larger rear bar can make a car understeer as well as a larger front bar to some extent - on 4th gens people usually run a vary large front with a small rear - but 4th gens are more tail happy than thirdgens.

I'm just trying to get the car handling as balanced as possible, don't get me wrong , the more I drive the car, the more I find that the limits are pretty high , definetly higher than a stock iroc based on feel - I just want more front end bite - the rear will not slide, sticks like glue.. I don't regret the change just want to tune it- I'll play with the tire pressures first - any other suggestions are appreciated

Souseless

Just noticed the difference in tire width; that is a big part of why the car feels like it is understeering. Are they the same model of tire? Perhaps a stickier front tire would help. A 24mm rear bar would help. Stiffer rear springs would be the other option. Going from the 36 to a 34 would be very noticable and with a lowered car you do not want to increase the amount of front body roll. I would work on the rear to get it to balance with the front, if tires are not the answer. But keep the big rear tires becasue they look badazz. It felt so wrong for me to disagree with crazyhawaiian on this, I must have been having an off day.

obeymybird

iTrader: (4)

hey kennerz just checking to see if you made any head way on your handling let me know

ME Leigh

If you increase the stiffness (bigger ) rear sway bar you will gain more oversteer. I would try the 36, 24mm combo, it will probably be just about perfect. Then you can adjust your tire pressures to get it perfect. Are you sure that you have a 23mm rear? I don't know if they ever made one of those, but i may be wrong.

Souseless

I was on the MOOG website and it looks like there was a factory 23mm bar.

ME Leigh

Do you have poly bushings? If not you could put them on the rear bar. This will effectively increase the bars stiffness.

Kennerz

Thanks for the reply's my password was messed up during the upgrade.

I think I will be looking for a very stiff rear bar either a 24, or 25mm I hear there is a 25mm this should return the balance I am looking for.

Plus my sterring gear is just slightly over tightened causing it to be alittle twitchy,


I do have factory control arms, the end-links are poly factory Iroc (very small white/or blue very hard bushings) FE2 I think

still open to ideas, lowere my rear tire pressure which helps , but I think the sway bar is a better solution,

For the record as some other have said, as it stands I don't really like the pro-kit that much and had I to do it agaiin I would have gotten the Koni's over the bilstiens. The stock Iroc springs seem to work better to me, I think Sam Strano would agree- I should have listened to him - however I do like the look and the rake is Ok with me...

I guess coil overs and koni's would be the hot set up if you could get the weights/ride height correct.... I hear it is hard to set up correctly though

LilJayV10

iTrader: (5)

Did you ever get your problem fixed? I am having the same problem but I haven't gotten the front end aligned yet or my good tires on it, so I can't say whats causing my horrible oversteer.

Kennerz

Well yes,


Here's what my problems were,

1. even with the slight lowering in the rear, I had only adjusted my panhard bar to stock length - my rear end was off center at least 3/4 of an inch.

once I centered the rear the problem improved greatly but not all the way - but was about 90% better than where I was before.

2. Adjusted the steering gear over center, then the over pitman adjustment per a post I read a couple of weeks ago - got rid of 90% of the play at the wheel I had about a 1/4 inch of play now it's like an 1/8 - I still need to look into where the play is from ( Steering wheel joint inthe colum is not tight, (those hex head /torqx bolts have never been tightened) or could be wheel bearings, or maybe my box) anyhow is better - not quite perfect but better -

I might break down and go for the complete turn-one steering gear, and pump, along with a flaming river shaft if I can't get it 100% right through all the investigation of steering components.

I want the steering to be fully restored and feel right, it's okay because I'm used to it after owning the car for 16yrs, but not 100%

3. Added a suspension techniques 7/8 or is it 1"? rear bar - car feels tight now- helped get the rest of the understeer out. better balance for the stiff 1LE 36mm front bar, along with the pro-kit front sping rate.

overall the low speed handling is very sticky say on 40~60mph turns (like glue), high speed stability is improved. can't really tell until I get the steering 100%

I rate the handling as good overall - the only thing is the rear spring rate of the pro-kit , or the ability of the bilstien shocks to control the spring is not that great in my opinion. on sharp edges the rear get's rocked even at low speeds. I like the bilstiens, but wish I would have bought the Koni's when I had the chance. I was afraid the ride would be too rough with Koni's , but now realize that a Koni SA does the best job of controling the springs for practically the same money.

I have koni's on my SS, and they are alittle harsh at low speeds but their handling more than makes up for it. Maybe I shouldn't compare a 4th to a 3rd gen Koni, but Koni's are the stuff.

Overall I'm happy with it, not trying to sound like I'm complaining about it, just if it helps someone make a better descision than I did,then this info is good.

I'm not the only one who is out to lunch on the handling of the pro-kit. Just I would say do your homework and figure out what you want. I really like the look on my car, totally satified- period. but the handling is a little confused in some situations - even with the best off the shelf parts. (car tracks off line really easy with bumps, and I'm not talking about bump-steer, on the other hand smooth roads are like heaven)

With 18"s and 35 series tires it would be horrible in my opinion, just make sure you never hit a bump..

I will listen to the autocross guys closer in the future, you never hear them raving on about the handling of the pro-kit. Strano had recommended stock Iroc springs and koni's- probably would be the best bet for street handling IMHO

Zepher

iTrader: (1)

Good that you got it to handle a bit better.

I have the tracking problem as well on grooved roads, where the car will pull left to right and vice versa depending on the road. this is due to tire width, at least it is on my car, 245/45/17 track fine, 245/50/16 track fine, 275/35/18 wander, 275/40/17 also wander.

I am running sportlines with KYB shocks and my car sits higher than most people with sportlines that I've noticed.

sully91rs

On tracking, has anyone ever drove over metal grating, such as on bridges, and feel like the car is bouncing and jittering all over? I'm not talking about the metal expansion joints on bridges, I'm talking about a 100 or 200 feet stretch of metal grated surface. My car rides great on regular roads, but as soon as it hits those metal grates, I feel like too strong on the wheel and I'm going to lose it.

LilJayV10

iTrader: (5)

I got my tires and GTA rims put on a few days ago. Tires are Pep Boy's Ultra Z's(which they don't make anymore)245/50 up front and 255/50 out back. The car handles a lot better. I still haven't gotten it aligned. The car tracks straight. I guess there is more to an alingment than just that. My problem is when i go into a corner, and get to turn sharp, the rear of the car snaps out really fast. The car doesn't roll, none than I can tell anyway, but the rearend doesn't feel glued to the road at all. I am going to get it alinged this weekend. I have aligned the rear end the best I can, can the alingment shop do the rear also? Thanks. I am not meaning to high jack your thread. If I keep having problems I will start my own. Thanks again.

Zepher

iTrader: (1)

Are you in any way braking or letting off the gas when you turn sharp?
doing either of these will cause the front to drop and the rear to get light (weight shift) causeing you to over steer.
Rear tires that are too hard, or not "grippy" enough can cause this as well.

here you can see that I turned too soon and then turned a bit too hard and started to slide out.
http://www.transamws6.com/video/spinout.wmv

LilJayV10

iTrader: (5)

I know it's comparing apples to oranges, but I just got done with EVO, emergency vehicle operations at work, and I can drive a crown vic harder, faster, and safer than I can my bird. to answer your question, the rear end snaps out when I turn sharp, yes it's worse if I give it gas, regardless of how much. The car feels very unpredictable, the car holds then just jumps out, I am scared to try to drive the car harder cause I am going to put it into a tree.

I have relocation brackets on the rear. what hole are they supposed to be in? I tried to read the sticky thread on it but it's over my head and I was lost.

LilJayV10

iTrader: (5)

I got the car aligned this morning. It drives alot better. I also checked the tire pressure, it was at 40psi. thats what the shop put in them when I had them mounted. Whats everyone running as far as psi? I dropped them down to 30psi. I am going to do a search and see if i can find something.

Souseless

liljayv10
Tire pressure is going to be different for different model tires. For street driving I would start at 38 front and 34 rear. The rear is always going to be lower.
LCA RLB the goal here is to have the lca level for most people. If you ar racing there are certain improvements from being a little up or a little down. I cant use them due to SCCA class rules so I have not memorized that info.

Your snap oversteer can be fixed with either swaybars or springs. I did not see any info about your suspension so I can not really be very direct. In general terms your rear suspension is too stiff with relation to the front. The fix is to either stiffen the front or soften the rear. My car is not quite what I want but it has 800# front springs and 175# rear springs with the 36mm front bar and a 19mm rear bar. I had a 24mm rear bar on the car and it had an unpleasant oversteer now I have a pretty good balance.

LilJayV10

iTrader: (5)

https://www.thirdgen.org/forums/susp...-rear-end.html

I started my own thread, sorry about high jacking Kennerz.

Kennerz

No problem...

Don't mind, I just wanted to state that I don't have any tracking problems and the rear feels pretty planted . However the rear spring rate is alittle soft in my opinion, or the bilstiens don't do a very good job of dampening them over sharp bumps.

My car is squirley over anything that involes bunps strait or curves, and only in the rear.. I blame the shock spring combo. A koni would do better I think. Smooth road handling is very good, with just a tinge of understeer.

San diego has crappy roads so anything with a solid axle is not so good, our money goes into politicians pockets not our roads out here..

oh yeah , the bilstien pro-kit combo is great in front, just not so sure about the rear