LilJayV10

iTrader: (5)

I feel bad because I ended up highjacking the other thread and didn't mean to. so I will start my own here.

Mods are as follows.

Spohn SFC's, LCA's, wonderbar, adjustable panhard bar, relocation brackets
Eibach Sportlines, Bilstein HD struts, sports in the back
36mm/24mm sway bars, poly endlinks, bushings
Energy suspension control arms bushings, trans mount, tourqe arm mount
Pep Boy 245/50/16's front, 255/50/16 back

I will try the 38/34 psi to start out with.

As mentioned in the other thread, in a sharp turn, the rearend will snap out, car feels flighty.

CrazyHawaiian

What kind of tires are those? Sorry, not familiar with the brand.

coolram62

iTrader: (2)

If the tires are hard compound they will break away(loose traction)much sooner than a softer compound tire.Why the lower tire pressure in the rear?The tires will flex more and react slower to axle movements.Just curious what are the max pressures on the tires you have now?

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.

I brought this over from the other thread.

The reason for lower pressure in the back is to increase traction. With a solid rear axle you need all of the help you can get. The tires are a problem here but they are the same all around the car so changing the rear tires would only serve to mask the existing problem.

LilJayV10

iTrader: (5)

The tires, they are Futura Ultra Z. I have used them before, I could cut a 1.86 60 foot on them at the track for whatever thats worth. Max pressure is 44psi.

Souseless, I listed the suspension mods in the first post which I am sure you saw.

Dewey316

There are a lot of pontential issues.

Are you hitting the rear bump stops in a sharp turn? Are all of your LCA bushing poly? if they are, you could be binding and the roll restance spikes, and you go to snap oversteer.

Does this only do it, in low-speed, sharp turns?

LilJayV10

iTrader: (5)

I don't think i am hitting the bump stops, it doesn't feel like it. Yes all the bushings on the car are poly.

niceroc

iTrader: (2)

could be that the rear sway bar is too stiff... or front not stiff enough... its a balance to get a car to handle good

LilJayV10

iTrader: (5)

The front bar is the biggest one they make. I have a 34mm also, and I think I have a 21mm rear laying around too.

matt_p

Start with the process of elimination. If your LCA's are very low in your brackets, raise them back to stock to see if you are getting roll-oversteer from them. Also, put rubber bushings back in your LCA's to see if the poly bushings are binding.

Two very simple things to start off with.

Souseless

Throw in the 21mm rear bar and if that doesn't fix it sell it to me Like already mentioned poly bushings are for drag racing. For cornering you want either rubber or rod ends. With the sportlines you may be hitting the rear bumpstops; how far from the ground to the top of your fender well? I wound up removing my front stops to gain more suspension travel and I had to raise the rear of my car a bit to stay off of the rears.

LilJayV10

iTrader: (5)

The LCA are spohn. I don't think I can put rubber bushings in them. I will see have the 21mm bar. The car feels good at higher speeds.
Poly bushings are used for drag racing? Do autocross guys use rubber then?
thanks.

DJP87Z28

In a sharp turn your best solution will be to let up on the gas. Thats one thing about a Camaro it will snap loose on you if dont let up, Its nothing to do with suspension parts but your driving.

LilJayV10

iTrader: (5)

I have considered that too. I am getting use to it. It's alot different than what I am use to.

Norm Peterson

Poly can be made to work fairly well in an auto-X environment, but you can't just stop at simply plugging the poly into the LCAs. You should also either back off on the rear roll stiffness by using a smaller sta-bar/lighter springs or mod the bushings in such a way as to remove roll 'bind' without compromising the fore/aft location too much. BTDT.

Norm

LilJayV10

iTrader: (5)

I am going to first change were the LCA's are in the brackets. Then I will try the smaller rear sway bar. The more I drive the car, the more I think it's the setup more than me. It's tough to explain on here. I will post a few pics of the car to show how low it is. I don't think it's that low.

LilJayV10

iTrader: (5)

I haven't had a chance to work on the car yet. The more I drive it the more I realize that there is something wrong. A friend of mine rode with me and made a good statment. when you get in a turn, just when the car should sit down and pull out of the turn, the rear comes out.

I was going through a sharp turn a week or so ago and someone came over in my lane, i jerked the wheel to avoid being hit, the rear came around, i countersteered and it snapped back and the rear came around the other way and went off road.

there seems to be a lot of people on this board with this combo, and no one else seems to have this problem.

Norm Peterson

Even the rear wheel width has something to do with this (it really should be half an inch wider than whatever width you have the 245's on). Softer lateral support means greater tire deflection while cornering, which translates to slightly less grip).

It's worth the minute it takes to check that both front endlinks are intact and that they are snug (no gaps or loose sleeves).

It really does sound like you've got too much rear roll stiffness, at least relative to the front. I don't know what the rear Sportlines' rate is, but I'll bet that it's enough stiffer than the OE springs that were engineered in combination with the 24mm bar to noticeably loosen things up.

I also have suspicions concerning the damping. One concerns the front to rear balance (HD vs Sports), and the other is that you may have bottomed out the rears and damaged them internally. A dead rear shock will produce sudden corner exit oversteer, at least that's one of Carroll Smith's diagnoses for this condition ("Tune to Win").


Norm

LilJayV10

iTrader: (5)

The reason i went with the sports on the rear is, everyone said, including bilstien, if the car is lowered, then go with the sports. the difference is supposed to be it has a shorter piston inside so it won't bottom out.

edited to try and explain it better