you can have all the power in the world, if you cant drive it-mrs. hotchkins in the minivan will beat you every time. a big percentage of racing is knowing how to race, as in launching, getting a good 60' time, shifting at the right times. even on road courses, ive seen STOCK civic hatchbacks tear up every muscle/exotic/tuner car on the track.
so its impossible to say what YOU will run with a turbo gsr. it depends on how much boost your running, how well its tuned, the tires your using, suspension setup, weight reduction, and of course YOU the driver...