All u gotz to do is open up handling.cfg in the SA directory, should be in data folder. Open using notepad, and turn word wrap off, ok now look for the car you want to speed up. You gonna see the codes, look for the bar at the top, it says A B C D blah blah.. ok, there, look for N and O.. N is rate of acceleration and O is top speed, or its backwards, trust me u'll notice which is which.. If you need more help.. just umm... reply =P