Originally Posted by N4BSE
cheers guys, yeah i just found some of the insurance companies got confused to what I had done, and either refrained from covering/quoting me or put a silly increase. So without causing upset to some members, what's the best option for a back box? I want something quite loud, but not silly inside as I do a fair few motorway miles. I had Eisenman before and thought it was good?
Check the exhaust stickies:
Except if mistaken, of all available exhausts for the 1M, so far only the Akrapovič has the possibility to either bypass
, at the touch of a button, a part of the exhaust flow through the rear muffler. By opening the butterfly valve with a wireless kit (pressing a button), a part of the exhaust flow bypasses the rear muffler and is guided directly through the outer tailpipes. The rest goes through the rear muffler and is guided through the inner tailpipes. By closing the valve, all the exhaust flow goes through the rear muffler and is guided through the inner tailpipes only (see the picture below).
So, if you spot a 1M with an Akra exhaust and there is smoke coming out of the outer tailpipes, the valve is open (or the blocking plate was removed if the car is not equipped with the optional Akra wireless kit) + you will notice a louder rumble.
A kind of Dr. Jekyll and Mr. Hyde system. Useful if you got to tone down in sound sensitive areas or when you're not in the mood for a more sporty sound.