Quote:
Originally Posted by kannibul
I also found it interesting that I'm hearing either some kind of backpressure pop or something along those lines, when downshifting the 7AT and engine braking only - kind of a muffled sound...(hit the paddle shifter, syncrho-rev kicks the engine up, tranny enguages, boof...ohmmmmmmmmmmmmmm hit it again...vroom,grab,boof..ohmmmmmm) - I didn't notice it before, but, then again the exhaust was quieter before  |
Exactly! You are hearing something that was already there, just better muffled at the time. (Love the explanation btw vroom,grab,boof..ohmmmmmm).
I used to subscribe to one of those urban legends (for lack of a better term) that stated that if you change to a freer-flowing exhaust, you have to richen the fuel mixture to eliminate the backfire (mostly on deceleration) or else you will damage your exhaust valves from the detonation. Of course like most legends it was all BS.
On my BMW K1200RS, I installed a Staintune full exhaust, which eliminated the cat. It has a sweet, mellow sound, much louder than before (I like that on a bike, since the
cagers can now hear me). But on decel, it backfires quite loudly. Fortunately it comes with an insert that screws into the tailpipe that muffles the backfire nicely while also giving it a sound that to my ears is not unlike a 911.