Actually we were running a IMSA GTO car in the mid 80's an we were a support race for the GTP cars. At that time I was talking to one of the mechanics on a GTP turbo car and they said that they were running 50 pounds at the time. The turbo was a monster in that it had almost a 8" exducer wheel and a about a 4 1/2 inducer wheel. Never saw such a big turbo on a car.
