Originally Posted by Kai
To make it look more sporty, I guess.
On the ITR, the rear wing is part of an overall design.
There are tracks in the United States where you'll be up around 135-140 before having to stand on the brakes to make a turn at the end of a straight. So you're slowing from 140 to 35 using ITR ABS.
It's a very good brake system; however, in this kind of braking there is a brief moment where you'll feel that the rear end of the car is trying to move faster than the front of the car, and the slightest steering wheel input from the driver while this is going on can cause some really scary feelings because almost all the car's weight has been transferred to the front wheels.
The wing of the ITR aids in keeping the rear end planted at the beginning of this kind of manoeuvre, when it's most important and most scary.
Jason Franza, the H2 Honda Challenge champion last year, tried to take his wing off at a driving event a couple of years ago, and he put it right back on after one session without it.
If you're driving the ITR on the track, you really want the wing on, and it really does do something.