Neep some help, front tire chatter how do I fix it??, Second day on track tomorrow Options

[trackbird]

My car does this in Autocross on low speed tight corners. I am also curious about this issue. It feels like the front end is hopping in my car.

Usually that's due to castor "picking up" the contact patch and the trick (as unnatural as it feels to do it) is to straighten the wheel some until the car turns as it should.

[FASTFATBOY]

My car does this in Autocross on low speed tight corners. I am also curious about this issue. It feels like the front end is hopping in my car.

Usually that's due to castor "picking up" the contact patch and the trick (as unnatural as it feels to do it) is to straighten the wheel some until the car turns as it should.

Opening the wheel and or getting on the gas makes mine go away.

[FASTFATBOY]

I took my spring rubbers out of the rear, it dropped the rear an inch(at least). Made the rear have MUCH more grip.

My axle snubbers have been trimmed about an inch, I can push the car down in the rear with my hands about 1.5 inches and you can feel them hit.

How much "free travel" should the rear have sitting still should they have? How far should I be able to push the rear down with my hands before they touch?

This post has been edited by FASTFATBOY: Dec 4 2013, 10:51 PM

[ReEntryRacer]

I took my spring rubbers out of the rear, it dropped the rear an inch(at least). Made the rear have MUCH more grip.

My axle snubbers have been trimmed about a half an inch, I can push the car down in the rear with my hands about 1.5 inches and you can feel them hit.

How much "free travel" should the rear have sitting still should they have? How far should I be able to push the rear down with my hands before they touch?

My 3rd gen has most of a turn removed from the 1LE springs, but I still use the upper spacer/isolator with the rear lowered to about the same as yours is.
I have cut about 1/2 the rubber from the limiters for the axle, but almost never hit them, and certainly can't do it using my considerable weight on my hands. It simple won't bounce that much with my DA Koni's set to give me the best cornering. I suggest heavier damping (and rebound in you have DA shocks) and maybe heavier springs too. JMHO

[FASTFATBOY]

I put the Detroit TrueTrac in the car, trimmed the axle snubbers and the car feels amazing. I have more grip on cold tires and damp streets than I did at the track. You get on the gas now and it drives out of the corner with grip, planted.

Unreal, wow!


On that test drive the rear was 3/8 lower than the front, I came back and put a length of heater hose on the top of the springs. The ride height now is 26.5 on all corners.


Now I want to get back to the track and see whats up.

[Blainefab]

I can push the car down in the rear with my hands about 1.5 inches

If you can do this with shocks installed then the shocks are shot.

With no shocks you can bounce the back of the car pretty good - hitting the bumps stops I think would be easy, but not a good metric for ride or bump stop height.

[FASTFATBOY]

I can push the car down in the rear with my hands about 1.5 inches

If you can do this with shocks installed then the shocks are shot.

With no shocks you can bounce the back of the car pretty good - hitting the bumps stops I think would be easy, but not a good metric for ride or bump stop height.

What about zero rake in the car?

I drove it again today with the rear raised even with the front, still good rear grip just not as good as it was (it seems).

No longer touching the bump stops on the street.

[mr.beachcomber]

No longer touching the bump stops on the street.

I may have missed it, but did you trim the bump stops when you lowered the vehicle? My rule of thumb was that the bump stops were trimmed to allow additional shock piston travel, but prevent the shocks from bottoming out at full compression of the suspension.

[FASTFATBOY]

No longer touching the bump stops on the street.

I may have missed it, but did you trim the bump stops when you lowered the vehicle? My rule of thumb was that the bump stops were trimmed to allow additional shock piston travel, but prevent the shocks from bottoming out at full compression of the suspension.

I at first had the black SLP stops on with the spacer and the car was all over them. I put the white Z28 stops on with no spacer, at the track the ass of the car was all over the place so I removed the rear spring rubbers.

This helped a BUNCH with rear grip but never got time to trim the stops at the track.

I just got around to trimming them.

Also installed a new diff in the car.

Big difference overall on the street.

[FASTFATBOY]

I can push the car down in the rear with my hands about 1.5 inches

If you can do this with shocks installed then the shocks are shot.

With no shocks you can bounce the back of the car pretty good - hitting the bumps stops I think would be easy, but not a good metric for ride or bump stop height.

I had a brain fart of sorts, the rack legs were under the car when I was bouncing it and this is what I felt hitting.