I used a 1½" holesaw with a 12" extension and removed the end of the secondary chamber, and as it was mentioned my 950 now has a pleasingly low, robust rumble. Compared to the stock sound, the level is now over twice as loud as it was but will not wake up or upset your neighbors. Since the stock exhaust has 2 chambers the primary chamber still gives adequate muffling but man oh!! man the sound you'll get by holesawing that stock exhaust. You won't want to spend $450.00+ dollars on after market pipes after hearing it. I don't think that I'll drill the air box at time, I'm a little leary about a too lean a mixture the ECU won't compensate so I'll do more research on that matter before I modify the air box.