Need advice spring rates for 968 PCA E class car
01-25-2009, 03:13 PM
#1
Rennlist Member
Thread Starter
Need advice spring rates for 968 PCA E class car
I ran my 1st race with PCA at Roebling Road in December, had a lot of fun!!! My fastest lap was 120.915, finished 3rd in E class in the feature race.
The event was 3 days, all told 10 sessions, mostly 30 minutes each, with the feature race 40 minutes.
I started with new Hoosier R6s, 18 in 245x35 front and 285x30 rear. There was some rain the 1st day and I ran Toyo R888s on stock 17 in wheels for 2 sessions. By the end of the wkend, my L front Hoosier was corded on the outside edge only, otherwise I could probably get 2 DE wkends out of the tires.
My suspension is a Racers Edge setup with spherical bearings, RE front A arms and Billet hubs, Leda shocks, front springs 800 lbs, rear springs 700 lbs, rear torsion bars turned down to 10mm.
My prior alignment specs were: front camber -3.2, caster 7, toe -0.10; rear camber -2.7, toe 0.
I had my alignment rechecked after the race: LFront camber 3.6, RFront 3.0, front toe 1/4 in toe-out; LRear camber -3.2, RRear camber -2.6. I know that is too much toe out in the front, and plan to get the car re-aligned.
I have had different opinions on the wear of the L front outside edge of the tire, both suggesting too much front understeer, with 2 different recommendations:
1- change rear springs to 1000 lbs, 2- change front springs to 550 lbs
I am concerned that 550 lbs for my car wt will be too soft in the front, or that 100 lbs is too hard in the rear.
I remember reading some posts in the past for 968s, having equal spring wts front and rear will move the car from understeer to more neutral, having heavier springs in the rear than than the front towards oversteer.
So, any advice on spring rates for my 968???
Thanks
Dave
The event was 3 days, all told 10 sessions, mostly 30 minutes each, with the feature race 40 minutes.
I started with new Hoosier R6s, 18 in 245x35 front and 285x30 rear. There was some rain the 1st day and I ran Toyo R888s on stock 17 in wheels for 2 sessions. By the end of the wkend, my L front Hoosier was corded on the outside edge only, otherwise I could probably get 2 DE wkends out of the tires.
My suspension is a Racers Edge setup with spherical bearings, RE front A arms and Billet hubs, Leda shocks, front springs 800 lbs, rear springs 700 lbs, rear torsion bars turned down to 10mm.
My prior alignment specs were: front camber -3.2, caster 7, toe -0.10; rear camber -2.7, toe 0.
I had my alignment rechecked after the race: LFront camber 3.6, RFront 3.0, front toe 1/4 in toe-out; LRear camber -3.2, RRear camber -2.6. I know that is too much toe out in the front, and plan to get the car re-aligned.
I have had different opinions on the wear of the L front outside edge of the tire, both suggesting too much front understeer, with 2 different recommendations:
1- change rear springs to 1000 lbs, 2- change front springs to 550 lbs
I am concerned that 550 lbs for my car wt will be too soft in the front, or that 100 lbs is too hard in the rear.
I remember reading some posts in the past for 968s, having equal spring wts front and rear will move the car from understeer to more neutral, having heavier springs in the rear than than the front towards oversteer.
So, any advice on spring rates for my 968???
Thanks
Dave
01-25-2009, 04:01 PM
#2
Rennlist Member
it really depends on how you drive and the shocks you are running but 800f and 1000 r is more like what seems works well. less rear camber as well
Mike
Mike
01-25-2009, 05:24 PM
#4
Rennlist Member
People have different styles...some like more oversteer while some like to toss it into the corner. It also depends on the track as well. a 968 will be doing some sliding (very controlled) to be really fast. Also, I have found as my skill improves I can control a looser car and avoid some of the inherent understeer that a 968 can exhibit.
Mike
Mike
