Suspension Improvements - F-Body Road Racing and Autocross Forums

Over the weekend I took the Camaro out to the Midwest Musclecar Challenge (www.midwestmusclecarchallenge.com/).

I had a blast, however I now am much more humble about my driving ability.

I have the power, I have the brakes, now I am ready to begin improving the suspension on the Z.

This, is where you guys come in.

Usage
Street - 1-2 times a month to work or cruises
Track - 3 or 4 track day events per year
Autocross - occasionally

Details about the car:
1991 Z28 hardtop

LS1/T56 Stock rear with 3.42 posi
C5 corvette front brakes, factory 91 z rear disks (HP+ pads and ATE superblue fluid)
weld in subframe connectors
Spohn tubular K-member

Suspension
boxed rear control arms
solid panhard bar
Factory 91 Z28 front and rear swaybars (not sure of size)
Eibach sportline springs (fronts cut 1 coil to level ride height after LS1 transplant)
no name shocks and struts from prior to 2003 when I bought the car.

Wheels/ tires
18X8 (245/40/18) front 18X9.5 (285/35/18) rear street tires. 200 treadwear

Be aware, I am not a rich man. changes only come slowly when I can scrape together extra cash. I need a priority list to tackle for best bang for the buck.

Questions:
1) I know I should replace the shocks/struts. should I jump straight to double adjustable or is there a less expensive option that will help?
2) Have I totally screwed myself up by cutting the coils on the Sportlines? What rates should I target?
3) Should I skip coils and struts and convert to coil overs?
4) Can I have a good setup for both track day and autocross without changes?

TrakCar View Member Profile	May 5 2014, 12:56 PM Post #1
Member Group: Advanced Members Posts: 37 Joined: 13-May 05 From: Louisville, Ky Member No.: 743	Over the weekend I took the Camaro out to the Midwest Musclecar Challenge (www.midwestmusclecarchallenge.com/). I had a blast, however I now am much more humble about my driving ability. I have the power, I have the brakes, now I am ready to begin improving the suspension on the Z. This, is where you guys come in. Usage Street - 1-2 times a month to work or cruises Track - 3 or 4 track day events per year Autocross - occasionally Details about the car: 1991 Z28 hardtop LS1/T56 Stock rear with 3.42 posi C5 corvette front brakes, factory 91 z rear disks (HP+ pads and ATE superblue fluid) weld in subframe connectors Spohn tubular K-member Suspension boxed rear control arms solid panhard bar Factory 91 Z28 front and rear swaybars (not sure of size) Eibach sportline springs (fronts cut 1 coil to level ride height after LS1 transplant) no name shocks and struts from prior to 2003 when I bought the car. Wheels/ tires 18X8 (245/40/18) front 18X9.5 (285/35/18) rear street tires. 200 treadwear Be aware, I am not a rich man. changes only come slowly when I can scrape together extra cash. I need a priority list to tackle for best bang for the buck. Questions: 1) I know I should replace the shocks/struts. should I jump straight to double adjustable or is there a less expensive option that will help? 2) Have I totally screwed myself up by cutting the coils on the Sportlines? What rates should I target? 3) Should I skip coils and struts and convert to coil overs? 4) Can I have a good setup for both track day and autocross without changes?

nape View Member Profile	May 6 2014, 05:41 AM Post #2
Veteran Member Group: Advanced Members Posts: 2,511 Joined: 14-November 04 From: Homer Glen, IL Member No.: 540	If you want to get serious about the street tire events, you'll want to upgrade to 18x11 all around so you can stuff 315s under there. That'd be your quickest upgrade. Here's my suggestion for suspension setup for 200TW tires: -800-900lb/in front springs, 150-225lb/in rear springs, 34-36mm front bar, 19-21mm rear bar. -Koni Yellow struts/shocks. -Unbalanced Engineering PHB relocation brackets (to lower the roll center, this will necessitate higher spring rates, probably 250-350 for STs.) Coilovers don't work very well on the front without longer A-arms, you end up very camber limited.