I hate to say this, but the bypass valve is necessary at the higher RPMs so that there is faster airflow out of the car. If you are going to be spending money on a exhaust fix you might consider spending the money to just upgrade to an aftermarket exhaust. It will improve your performance a bit and the sound.
A forum community dedicated to Ferrari owners and enthusiasts. Come join the discussion about performance, build specs, production numbers, modifications, classifieds, reviews, troubleshooting, maintenance, and more!