to make this faily simplistic and try and rule out any free standing variables...
all cars manual transmission
all cars with equally skilled drivers
from a 40mph roll
all cars stock
wrx vs rx8 = wrx should get a jump and hold it for a few seconds but then the RX8 will pass you right around 60mph and continue to do so. To pull on an RX8 from 40 to (lets say 90) you would need TBE atleast.
wrx vs rsx-s = same as the RX8 but the rsx wont pull as much towards the end. They trap right around where we do, so it should be a good race for a while, but after 80-90mph the rsx-s will start to have the advantage and may put some ground between you.
rsx-s vs RX8 = quite close at first but near the end of the race the RX8 will pull a car to 2 due its couple mph higher traps.