Streetracer780:
Seeing as how you've already finished this race (80'S Beginner), this info may not be as useful. might help others out though.
I jumped in to my Silvia K car (1800, won earlier) grabbed an oil change and added a Semi Racing Suspension, sports brakes, chip, racing Muffler, stage 1 turbo, Racing Intercooler, super slicks (didnt really need), and stage 2 weight reduction.
Bottomed out the Suspension, Auto Setting=24, and went for it.
80s Sports Car cup Beginner
SS Route 5
Mazda RX-7 Inifini 3: +5.263
Skyline GTS-t: +8.455
Silvia K: +10.541
Mazda MX-5: +16.143
Sprinter Trueno: +16.351
Best Lap: 140.030
Tokyo R246 2
Sprinter Trueno: +3.885
Mazda RX-7 Inifini 3: +6.154
Skyline GTS-t: +7.906
Silvia K: +10.199
Mazda MX-5: +13.593
Best Lap: 159.357
Seattle Circuit 2
I absolutely HATE this course (1 & 2), and it shows. I managed to pass the SS after the last turn, on the final straightaway. Had a tough time keeping the back end behind me.
Sprinter Trueno (SS Version): +0.941
Mazda RX-7 Inifini 3: +3.593
Silvia K: +5.340
Sprinter Trueno (AE 86): +8.067
Mazda MX-5: +8.246
Best Lap: 153.828
I pocket a few credits and a Mazda RX-7 Inifini III.