I've also written a career walkthrough which includes tuning for the better cars in career mode:
LinkUse the cheat code
unlockallthings
to unlock stage 4 parts for purchase. This works on the unpatched version 1.0 of the game.
Setting gameplay assists to casual will slow down the AI.
Most of the setup parameters have little or no effect on lap times. Lowering tire pressures helps the most. Lower ride height only seems to help the Ford GT, and it doesn't improve grip, it just keeps it from rolling as much. Increasing ride height can help in the bumpy turns at Texas Oval.
Zonda grip. All stage 3 parts. Tuning: tire pressures -10 (all the way left), steering +10 (all the way right), engine and nitrous +10, gears -10, final 0. Note that 911 Turbo has a higher handicap, so you get more points with it.
911 Turbo speed. Stock parts: suspension, brakes.. Stage 3 parts: engine, drivetrain, turbo, nitrous, tires. HKS turbo may be better. Stock suspension keeps car from going airborne over hills. Tuning: both tire pressures +10, engine and nitrous boost values +10, all gears and final 0 (middle).
Camaro SS is the fastest drag car if you can launch into 5th gear at the start (depends on platform, and if you can assign a button for each gear, only need to assign one for 5th). Zonda is next fastest, then the Supra. I don't have a stage 3 Zonda setup.
Camaro SS drag parts: Stock: suspension and brakes: Stage 3: engine, drivetrain, supercharger, tires, nitrous. Use Eaton twin screw charger. Tuning: front tire pressure +10, rear tire pressure -10, both nitrous boost values +10, gears 1->4 +10 (not used), 5th -10, 6th 0, final +10. Launching: hold rpms above green area, hit 5th gear and nitrous at same time to launch. Leave car in 5th gear for 1/4 mile, shift into 6th for 1/2 mile.
Supra drag parts: Stock: brakes. Stage 2: suspension. Stage 3: engine, drivetrain, turbo, tires, nitrous. HKS turbo may be better than others. Tuning: both nitrous boost values +10, all gears and final +10.
Zonda drag parts: Stock: brakes. Stage 4: engine, suspension, drivetrain, turbo, tires, nitrous. HKS turbo may be better than others. Tuning: Front suspension paramters 0, rear suspension parameters +10. Front tire pressure +6, rear tire pressure +10, engine and nirous +10, 1st gear -10, 2nd gear +9, 3rd and 4th gear +10, final +10.
RX7 drift parts: Stock: suspension, tires, brakes. Stage 3 (or 4) parts: engine, drivetrain, turbo, nitrous. Tuning: engine and nitrous +10.
Charger R/T wheelie parts: Stock: brakes. Stage 3: engine, drivetrain, suspension, supercharger, tires, nitrous. Use Eaton twin screw charger. Tuning: front shock compression +10, rear shock compression -10, front shock rebound -10, rear shock rebound +10, front spring +10, rear spring -10, ride height +10, front tire pressure +10, rear tire pressure -10, both nitrous boost +10, gears all 0 (middle).
[Edited by jeffareid, 5/27/2008 4:17:08 PM]