1970 Corvette ZR-1
I began running this in the 2 minute warning March challenge at Mugello. It had a very good lap there running a setup with a 49.9% weight bias, springs at 73% and bars @ 14.8 each, 29.6 total. The dampers were at 6.5 rebound and 3.4 bump, rear DF:68 and diffs @ 12/30.
However, I discovered after moving to Suzuka, that this setup was much too 'on-the-edge' for running consistantly and at other tracks. The rear end wanted to jump out under aggressive acceleration so, I knew that I would need to soften the springs to get it to hook up better. The car was also sliding around pretty good so, I lowered the overall amount of bar to 28.9 total. Dampers were softened and diff decel increased in an effort to keep the car from oversteering under high, prolonged cornering forces...
After moving to the third and final track, Sebring, the car got some additional transmission and alignment tweaks but, the biggest difference came from the dampers when I used the default relationship of spring to damper to apply new damper settings to my current spring levels.
The Build
Powertrain: All stock
Platform: Stock driveshaft, sport flywheel and weight, all else race
Aero: Forza race rear wing
Rubber & Rims: Bridgestone 225/45R19 DOTs front & rear on Fiske Profil 5S rims
370HP, 380Tq & 2925lb curb weight, PI700
The Tune:
Tire Pressure:
Front: 29
Rear: 28
Gearing:
Final Drive: 3.93
(1): 2.50
(2): 1.60
(3): 1.10
(4): 0.90
(5): 0.80 ( not used )
(6): 0.75 ( not used )
Alignment:
Camber Front:-0.6
Camber Rear: -0.6
Toe Front:0.2
Toe Rear:-0.2
Caster: 5.8
Anti-Roll Bars:
Front: 12.96
Rear: 15.91
Springs:
Front: 585.7
Rear: 482.4
Ride Height:
Front: 5.2
Rear: 5.1
Dampers:
Rebound Front: 5.6
Rebound Rear: 4.6
Bump Front: 2.8
Bump Rear: 2.3
Aero Adjustment:
Front: n/a
Rear: 66
Brake Bias:
Bias: 48 %
Pressure: 82 %
Differential:
Rear:
Accel: 10%
Decel: 40%
So, the 'final' numbers are 54.8% spring bias ( 49% def )
73% springs ( -2% from def )
ARBs @ 128% of default with a 45/55 split
