My car has a PPF fitted and has never felt lacking in any grunt when the bum Dyno has been in use. The 60-100 time of 5.7s was pretty brisk in my consideration, but hey ho, I thought I'd just stick it on a Dyno and see what happened
Stock power is quoted at 335bhp and 500nm for torque. It did 4 runs and went from a lowest of 355.9bhp & 544nm and a 360.1bhp & 551nm which I'm sure you'll agree is quite healthy. We compared with data sheets from tests on the same Dyno of a non-PPF car and the variation was negligible.
Quite pleased with that!