Quick question concerning Exhaust and muffler.
 

Porsche 928 S4 1987 North America

Do you guys knows the diameter of the exhaust pipe just before the muffler.

I want to change the actual muffler for 2 more muscle car sound performance mufflers.

The RMB is not a good idea here in Quebec, Canada. (Cops are crazy).

I don't have access to my car for the winter and i wanted to order it for the spring.

the RMB is really NOT loud....unless you have it floored and higher RPM. Plus it is easily reversible to put all back to stock. The pipes have bell shaped flares on the end with special couplers...cut them off to roll your own and it never goes back....
If you have no smog emissions tests a proper X pipe will add horsepower and SOUND giving a higher European note rather than sounding like an old Chevy pickup with a rusted off muffler....

The RMB is not loud if compared to a Harley, but it is louder than most cars on the road, but not all. the 89 with RMB is only slightly louder than my sons 944s with a performance muffler. So it can be passed off as factory.

I think it sounds much better than a chevy pickup with a rusted muffler, but that is my taste. My wife doesn't find it unacceptable, however she wishes it was a little quieter on those occasions when she takes it to school, although she tells me know one has ever mentioned the sound, although many have asked about a kindergarten teacher driving a Porsche.

The constabulary are not going to know that it is a RMB, unless they are very familiar with a Porsche 928, in which case they should give you a pass:) .

If they look underneath they will see 2 cats and 2 resonator/mufflers and the RMBs looks factory, which should be enough for a pass.

I don't think that you will have any problems with the RMB. From what I've read the X-pipe adds another level, not yet having installed one I can't comment on if it will be over the top or not.

I believe the stock diameter is 2.25 inches.

Cheers!
Carl

Someone can validate ?

It is actually a little over 2". 2 1/8" is the closest measurement I have.