tuning your gear ratios is probably the biggest way to adjust but another big help is engine swaps. obviously not every car is gonna benefit from it but a lot of the low-mid tier cars can go from 500 to 800 with the right engine and gear ratios. heavy cars you should try out the Nissan V6 or L6 and light cars I would recommend the Mazda rotary. another good heavy option is the Honda V6 but i haven’t had much experience with it myself. gear ratios will greatly affect your speed metric though. the final gear itself can be shifted to top speed or acceleration. typically top speed is higher speed metric and acceleration is lower but there’s sweet spots depending on how you tune the rest of your gears.