[supraguru05]

for refernce i drive a mk3 na supra. ive been autocrossing for 1.5 years now and just this year have started to understeer quite a bit. the cars setup last year was koni yellows soft on front and med on back. with eibac progressive springs. personally the setup comepltly sucks but it didnt push. this year i have changed all the shocks to full stiff and have put on a set of st sway bars. i also insalled spring rubber in the front and back. now the car pushes really really bad. i belive the issue is the front springs being to soft/the front shocks being to stiff. is this a right assumption. the front of the car loads really hard it just compresses the spring alsmost all the way

 

[bwill]

You end up driving the "stiffest" end of the car. You might therefore need more front spring. Softening you front shock relative to the rear might help. More camber up front might help. Driving style can contribute to understeer which is another possibility. Monkeying with tire pressures using a pyrometer and tire pressure gauge can be a nice tuning tool as well.

Barry H.

 

[supraguru05]

thanks for the advice. i have taken full responsibiity for the poor handeling of the car however that being said the eibac rate in the front is 330-650 with the stock ones being 460. so there lies the problem i belive. i plan on dialing in a little more cmaber in the front and taking some out of the rear because i am chewing tires. thanks for the reply ill keep you all informed

 

[nils]

in a nutshell, soften the front & stiffen the rear.

also, if your springs are compressing all the way to your bumpstop, well then you are F'ed.

n

 

[Rafferty]

The easiest change(s) would be to soften the front shocks, add toe-out in the front (as much as 1/8" per side - don't drive it too much on the street this way!) and loosen the front sway bar mounting bolts so you get some turn-in before the big bar hooks up. If the car completely washes out on corner entry, I'd suspect that you have too big a bar on the front and need to go to something smaller. Try disconnecting the front bar completely for one run just to see how it works - I bet you'll be surprised.

Btw, the Koni/Eibach combo -while not ideal - is not a bad setup for autox. I ran a similar setup for years before I went to coilovers.

Kent Rafferty
93--GT35R

 

[prsrcokr]

FWIW, I've got a similar setup on my mk3 (Eibach w/ Tokico Tems shocks and ST bars F&R) I'm also not using the rubber bushings any longer.
I haven't noticed the car push unless it's due to my corner entry. Oversteer has been the biggest issue to date and this was increased with the stiffer bushings. What kind of tires are you using? I've got -1 front (max available) and -2.1 rear camber, caster and toe per specs. I'll dial out some camber and aim for 1.5 this weekend to try that.
HTH,
Brian

 

[mifesto]

yeah i would slightly increase pressure in the rear, get the -1 camber in the front. i bet just that would make a noticable difference.

as for driving, have u ever tried left foot or trail braking? those techniques will help u rotate your car alil better.... often used in FWD and AWD cars but this may help u too.

 

[prsrcokr]

I just thought of another thing along the lines of Ken's response (I have nowhere near his experience so listen to him first )
I thought it could be possible one of the endlink tabs has broken on the rear sway bar (these are known to commonly break on the mk3) or even the link itself. Just an idea.
Brian

 

[supraguru05]

ok heres the sugestions ive been given

soften front shocks
decrease front sway bar
more camber in the front
more pressure in the rear
decrese and increase spring in the front

o these i plan to soften the front shocks and actually run rubbers in the front to make them a little stiffer to stop me from rubbing. im going to dial in -1 camber in the front and in the back i already have a lot of camber. konis are a completly differnt monster then tokicos. my car rotated fine last season thats why i belive the shocks on full stiff are causeing the problems. ill post some new pictures and videos possibly from the 11th