Forza Motorsports Tuned Cars

How to tune ur car in forza motorsports 2?
how do u tune cars in forza motorsports 2 i dont get it i but all all the right parts then i go to tune car and i get lost from there i am trying to tune an A class galardo
It depends on the course your racing, if its a short twisting course with no long straights then tune the gearbox to have a shorter over-all range so you get better acceleration, and do the same for the spoilers. Likewise, if your on a longer course with more straights, tune them in the opposite direction, to gain better speed, sacrificing acceleration. Generally however you dont need to tune cars much to be succesful, I found tweaking little things here and there was a little helpful but it was more phsycological then anything else
My Datsun 510 (tuned) On Forza Motorsport 3