February 20 2013
997 GT3 Noise Problem Solver!
This is a very simple trick that for the GT3, which having lots of noise issues, is worth it's weight in gold.
It involves putting a 6mm vacuum cap on the valve for the exhaust bypass. The effect is that at high RPM you continue to use all 3 silencers rather than the side boxes being switched out. It chokes the top end of the power band noticeably, but it will get you out there at almost all venues - so long as you aren't dreaming of Thruxton it ought to do the job for you.
You can buy them from eBay for nothing at all. Here's one we found. Rubber Vacuum Hose