i just got my 04 cobra tuned on E85 and it made 693hp and 688tq with a sliping clutch on 19psi
since your in dallas who tuned it hpp or gearheads?
also i wouldnt think about pushing 750 thru rails..
and what kind of turbo is it if it wouldnt make any more boost? could be a wastegate or controller problem?
single 72mm turbo ,twin gt pumps ,kb bap ,8an line,80lb injectors, stock fuel rails the tuner told me that he could have made around 750hp with my fuel system i was at 70%duty cycle but the car would not build any more boost