Originally Posted by PR3CI5N
People can say it doesn't add any power but it does from 5500k to red line. The car feels like it can breathe better. Obviously the PE doesn't add 20-30 whp but the power difference is noticeable. I didn't buy my PE for the performance though, I bought it for the sound. I bought my DP's for performance. I bought my PE used for $800 off a member on here so as long as you find a good deal I think the PE is well worth it.
Its not just people who say that its what BMW says, they list max gain of 8 crank horsepower at top end. $100 for 6.8 wheel horsepower for a few hundred RPM is not a very good deal. With a normal system they can make a nice sound but they are of no real value in generating any usable power.
Also the 335 is pretty much all done in by 6300rpm based on any twin turbo dyno runs I have done or seen. In fact the default JB4 shift light setting is at 6K & is what the development cars are shifted at.