After installing the GEN II cat back system onto Sidw 's M135i we thought we'd do a sound comparison between the Powervalve system in 'Auto' mode - which effectively has the valve closed in the free revving mode, and then with the valve in the 'full time' fully open position, thereby allowing a more direct comparison with the MPE rear silencer....
The Actuator arm mod will enable you to set the valve position exactly where you require it between these two sounds.
Of course this will not affect the boosting position. Sport mode position is also unaffected and will still affect and interact with the Powervalve.
Just to reiterate this sound comparison features the BMW OEM Cat - not the BCS Powervalve cat which will impact further on the sound.
Hope this helps
New sponsor coming soon.............
1 post • Page 1 of 1