So, Evan and I are getting closer and closer to dialing in the car, but it still is a bit rear traction limited. We saw an improvement in predictability, but maybe not more absolute grip when moving from 225lb to 300lb springs. We certainly carried the inside front wheel less and it never snap oversteered...

I'm already very low in the rear, but could use some more camber I think. The Hoosier A7's love camber... I'm also considering a hair more toe in. I'm currently at about 1/8" total toe in and probably get a bit more.

Current basic setup:
Raised spindles - 19mm
Rebel Racing Front and Rear (teflon) bushings
Camber plates
21 mm torsion bars
21 mm front sway bar (set fairly stiff)
300lb rear springs
Koni Yellow rear shocks
Bilstein front shocks

Alignment:
Front:
2.2 degrees camber
6 degrees caster
0.13 degrees toe OUT
Rear:
2.4 degrees camber
0.13 degrees toe IN

I know this is a fairly unconventional set up, but it has been slowly built up and has proven itself to be VERY FAST in the rather large POC/PCA courses we have down here.

For example:


https://www.youtube.com/watch?v=WM72u_fqmX8


Is there anything I'm missing short of an LSD for picking up some rear grip?

Hey Aaron, your running just about the same set up as I am. I run a little more toe than you ( in and out). I have less rear spring with a bar and Quaf. The back end is planted but I have a little push. I found less front camber and I would like to run a little less air in the front. I worked all of that out in El Toro. They really didn't like the car. I have to be back in OC is n July. I'll have to check the OCR calendar. In case you haven't noticed I am putting wings on Carerror. When I started the project I thought she needed a little weight up front.

Joe's comment actually points to the best route probably: Work at taking away front grip incrementally, without adding enough roll stiffness to pick up the inside wheel. In other words, work with the tires.

The 300lb springs got the front, inside wheel more-or-less down on the ground again. I had a few things I was thinking of trying.

* Less toe out in front, less caster in front, soften the front bar, and add slightly more rear toe in. Leave static front camber in the 2.0-2.2 range (this is my likely first step).

* I have a 275lb set of springs. One school of thought is softer = more grip, but I think that only works if you aren't already getting roll over oversteer...

* Add yet more rear spring (400lb??) to keep the rear from rolling over as much and maintain camber.

I don't think a rear bar will help without an LSD and that's simply not an option due to the expense. After the 300lb spring update, I'm no longer spinning up the inside rear tire as badly (or really at all).

Joe, PCA OCR basically imploded. All of us are now running with the newly minted POC Autocross series.

https://www.motorsportreg.com/orgs/porsche-owners-club

Doesn't really fit into the "budget" but I think a good set of custom valved shocks for the rear would help a lot. (front shocks are custom valved Bilsteins from Erik Madsen's 914-6 EP car before he went to Ohlins).

Running off the shelf Koni Sports just can't provide enough rebound dampening for 300lb/in springs. Cranking up the knobs on the Koni's the last outing made the rear grip issue worse which says to me that the springs are providing plenty of stiffness but whatever the bump to rebound ratio Koni uses when you turn the knob on the single adjustable shocks isn't working for the stiff springs. Running the shocks on full soft with triple the stock spring rate has me thinking that's an area of improvement.

But the car is fast and fun so maybe we should just keep feeding it tires and keep the bolts tight and focus on the driver mods..... that's where the big gains are anyways.

-Evan

I agree with Evan. Shocks and driver improvement.