a little car set up help

[DelSolBurrow]

As you can tell by my name I drive a del sol and i am sure you have seen me at the events. I was looking for a little help with fine tuning my set-up so here is the vehicle...

Full coil - overs with 12k front spring rate and 6k rear. they are 15 way damping adjustable. I have strut bars front and rear as well as a roll bar, A 22-mm rear sway bar that is non adjustable, Slotted front rotors with Endless vita nuova brake pads, Upgraded blank rear rotors with hawk pads, Stainless steel brake lines all around with a very high boiling point DOT 4 brake fluid, and I am running on 205/55R14 Avon tech - R tires.

the current set- up i run is 2 clicks of 15 for front damping and 11 clicks of 15 for rear damping. tire psi is 30 front 35 rear.

car feels really good through high speed corners and slaloms with this set up but i have really noticed that under braking it gets a lot of oversteer and seems rather unstable. If i lower the rear damping will this help correct this sensation? lowering rear tire psi? any of your many season guidance would awesome!

[woodrufj]

What does the adjustment do on the shocks? compression, re-bound or combined?

Off hand, looks like a big rear bar. Just for giggles, disable it for a run see what happens.

Jay W
505/287 Dakota

[MX5bob]

car feels really good through high speed corners and slaloms with this set up but i have really noticed that under braking it gets a lot of oversteer and seems rather unstable. If i lower the rear damping will this help correct this sensation? lowering rear tire psi? any of your many season guidance would awesome!

Sounds like too much rear brake bias. You might try a less aggressive pad in the back and something with more bite up front.

[Steve35]

I agree with Bob on the brakes, but according to Carroll Smith’s “Engineer in a Pocket” booklet the additional problem(s) may be:

Insufficient rear droop travel
Wildly uneven corner weight
Excessive rear damper rebound force
Unbalanced ride/roll resistance-too much rear
Insufficient rear camber (usually in combination with one or more of the above)

Good luck!
Steve Coe
www.C2Racers.com

[DelSolBurrow]

the damping is combined and if i disable my rear bar i have horrible understeer, it's not just for giggles.

as far as the pads go front and rear i was certain my Endless pads were way better than the hawk, at least they better be, i spent 120 on just the front pads. lol But i will look into what i should maybe run in the rear. Normaly the way my car wears brake pads is about 2 sets of front pads per every 1 rear set. Ever since i upgraded the system they have been wearing perfectly evenly. Would that be a sign of to much rear bias?

should i lower my rear tire PSI to 30 as well?

for the list that steve mentioned...
1.Insufficient rear droop travel
2.Wildly uneven corner weight
3.Excessive rear damper rebound force
4.Unbalanced ride/roll resistance-too much rear
5.Insufficient rear camber (usually in combination with one or more of the above)

I would say 1 & 3 are most likley my problems

would raising the damping to a stiffer setting (since compression and re-bound are combined) help item # 3? cause it would keep the tire from coming down as quick? or do i have it backwards and it should be a softer setting?

Steve, does C2 do corner weighting? i have been wanting to do that but have no idea where to go.

Thank you guys for your help, I now have a lot to test on the 22nd.

[Steve35]

Steve, does C2 do corner weighting? i have been wanting to do that but have no idea where to go.

We sure do! Call me.
(858) 495-9200

Steve Coe
www.C2Racers.com

[Mazda_Gremlyn]

Have you thought of adding a larger front bar? If your diving on turn-in, the back end will come around much easier due to the rapid weight shift. I would also try dialing back a little on the rear shocks. Its easy enough to test and adjust, especially if you do a practice event (like the one of the 22nd).