i have an 86 camaro, i'm running eibach pro-kit springs and tokico illuminas on all 4 corners, the whole suspension has been rebuilt, poly bushings everywhere, i've put in 36mm/24mm sway bars, my problem is, when i enter let say an s curve, it feels like the front wants to dive in to the turn like it's steering more than me, is that oversteer? how would i correct that?

 

86Z-
Generally, that would be oversteer....BUT...classic oversteer is NOT the front end tucking. It is the rear walking out on you.... going in OR coming out. Power oversteer is the most commonly encountered... give it a bunch of gas, and the tail swings wide.

From what you have you should NOT have oversteer.
Is your alignment set right? Too much toe in will make it steer funny.
How are your shocks set? Maybe you are compressing so quickly, you are overwhelming your front end and causing it to tuck. Try cranking some more shock into your struts.
Post how you do. I have been curious about the Illuminas myself. My 19 year old Formula GPs are starting to go.

 

i'm running all the shocks on #4 setting which is firm, i think there is a 5 setting which is max firmness

 

Loosen your rear shocks to one or two.
Post if that helps.

 

When the front just pushes like you are describing that is called understeer. You might want to try turning the wheel a little less. Sometimes people just crank the wheel all the way over because they think it will turn faster the more the wheel is turned. Also, instead of turning it really fast just try turning slow at first to get the weight of the car on the outside front wheel then once the weight has been transfered start turning the wheel faster. Then again, maybe you were simply going to fast. Slowing down a little will reduce the cars tendency to dive into the turn causing understeer. Trust me, it may sound dumb but slowing down actually improved my times for autocross. If you are intent on keeping your foot through the floor, try playing with the shocks like Flip 2 said. If there is a firmer setting up front, put it there.

Mike

A little off topic, but...
How do the springs feel? Is the lowered ride height noticable? Do they feel soft at all? I just ordered the Eibach Pro-kit, Koni Yellows, and Hotpart strut mounts yesterday and can't wait to get them on the car.

 

i'm not turning too much, this is normal driving on the street, i go in to the turn and it feels "heavy" in the front

 

You just threw me for a lop with that "heavy front" comment being opposite of what you first wrote about tail happy but I think I am interpeting what you really mean. I will assume by a heavy front you mean it stays planted and the rear is dancing. (Note: a heavy front usually means the car is tight and will not turn- genearlly, too much spring rate) but sounds to me that you do not have enough front spring rate and you are interpeting the front rolling over as heavy.....? Hope we are on the same page, otherwise, you will have to correct me.

The best basic adjustment you can do is what Flip2 suggested already to reduce the rear shock damper settings. The Tokicos are single knobbed so the compression and rebound will adjust together. Click it down in the rear and it will dynamically load the font outside tire quicker than the rear outside tire going INTO the corner, but you will still hurt on steady state and the corner exit will be a tad better. Shock adjustment in the rear will only semi help your problems. You really need to get rid of that heavy rear swaybar and or increase your front spring rate. Too much rate will make the car loose mechanical grip, too little spring rate will allow too much steady state body roll asnd also loose mechanical grip on the inside tires. Too little sping rate can be controlled through increasing reound settings, but you do not have separate dampoer adjustments from compression to rebound. you need a balance of sping rate front and rear for a good steady state balance.

The worse thing most people do is to have soft springs, heavy asre swaybars, and inaddequate valved shocks to control the chassis. This is very common in most lowered "performance cars" you see on the street where people have tried to upgrade the handling of a car. They often handle worse and may just seem better because they feel more locked up from roll. Problem lays where the suspension skips accross the ground rather than mechanically conforming to it with front and rear balance in proportion.

 

Pro-kit springs are 714lb/in linear front and 109-177 progressive rear.

Did you put poly bushings in the stock rear lower control arms? That does weird things with the roll stiffness.

 

yes i have spohn tubular lower control arms, poly bushings all around, lca relocation brackets, etc.. i'm going to try a 21mm rear bar and see

 

The rear lcas with polyurathane can lead to problems when they bind and then release. Might want to look into replacing those.

 

I've been autocrossing for a while with rod/poly LCA's without a problem. Am I just lucky, or am I correct in thinking the rod end is reducing all the bind I get with the poly.

 

Correct. The problem arises when there is a poly bushing in each end, which will cause a bind. What usually happens with poly bushings in each end is that they are stiff enough that the LCA bends before the bushing deforms, and does so rather suddenly when it gets enough load on it. It creates a "false
" initial roll stiffness that goes away all of a sudden. The natural motion of the suspension puts the LCA in twist, and it needs to be able to move. The rod/poly combination is the best for anything short of an all-out race car. A poly bushing in one end and a new rubber bushing in the other is better than a poly bushing in each end.

 

I had a set of poly/poly LCAs on my car, and encountered the same thing on several occasions. I build the LCAs you can see on my CarDomain. Heavy duty rubber on the body and rod end on the axle.... which need replacing.

 

how can you tell when the rod end needs to be replaced?

 

You can start to hear them from in side the car. Also, you can take the end without the rod end loose and move the linkage while looking for any movement in the rod end. I'm actually thinking about replacing all the rod ends with the HD rubber ends.

 

Rod ends have a wide range of quality....
One way they fail is to get loose.... that will give you the clunk TPI describes.
Another way is, they will bind, and eventually freeze (especially the cheap ones).
Never use aluminum, even though they may have a high burst rate, they WILL fatique and fail.
The longest lasting, BY FAR, I have seen are the Teflon Series from Rod End Supply (in Kansas, I think). They have wide square-ish bodies, so are not very good for any app where mis-alignment is an issue. Otherwise, they seem impervious. They would probably fare well at they front end of our trailing arms. TPI, they could be an option for you.

 

Rod end quality....
The large ones are what I have on my Camaro- They aren't cheap, but they are pretty much bulletproof. I also run them on my front upper control arms on my Chev truck (I custom built the front suspension on the truck)

http://www.cardomain.com/member_page...2_155_full.jpg

 

The ones on my car are the nicer QA1s (before they sent their manufacture to China). I think they are what Spohn uses and what Vetruck has on his.
I was poking around on FRRAX a while back and found the ones I think I'll use if I go back to rod ends. I'll also look into the ones Flip mentioned.

 

Just in case anyone was wondering, i set the struts and shocks to 2 and the car handles like a dream now.

 

Out of curiosity, were you at least originally using the lower holes in your LCA relo brackets? If your LCAs were running 'uphill' from the axle toward the chassis, that also tends to make a torque arm car loose.


Norm