till u reach the limits of the sepention . with my 73 polara i thought it would do 150 but @ 142 it wouldn't steer ( front end was flooting too bsd so i lifted . this was done on a top end track at the chryslrr provif grounds back in tye late 70's-early 80's . mmci went there 2 times i think it was 1979 or 1980? when a 69 daytona tryed it they closed the top end run off to us (they didnt want us to chrash ),or get hurt as wewas guest there