it was patched
410 MPH? is that even possible on the game?
http://forums.forzamotorsport.net/blogs/turn_10s_forza_motorsport_blog/archive/2007/06/08/230749.aspx
Really it depends. In terms of tuning you really do have to find your own feel to the car. And also it comes down to the car that you have. If you have a Mustang and a Lamborghini, they will need to...
In real life you'd have a high tire pressure and tight suspensions and lower the car so that the aerodynamics help with speed
There are no cheats in Forza 2.