The weld on the round plate at the front (engine) end of my MBRP 4" muffler blew a 2" leak. This is the second time in 100,000 miles. Both times on the front plate. MBRP replaced the first time- no charge.... said never seen it before??
-Too much pressure from my set up?
-Why front end? Wouldn't the rear plate (rear axle end) take more blast/stress?
-Anyone else had this happen?

Bought a 5" system from Rip that I did not think I really needed... but while figuring how to get the 4" off in reusable condition, discovered the leak. Guess maybe I do need 5"?

RJ

 

definately "need" 5in... zero negative effects with your setup, only positives...

I don't see why it would blow up front either, only thing I can think is maybe vibration is playing a part? (just a WAG)

 

Rip told me a year or so ago that when he was at ~620hp, switching from 5" straight to 4" straight netted him a 10hp loss...but that he really like the decreased noise, so he took it!

Personally, with those twins, a 5" straight should be plenty quiet, and sounds mean with all the whistle!

I think you'll like the 5" RJ As far as the 4" muffler weld breaking, I have no idea!

Chris

 

yup, with twins 5" straight pipe was just downright quiet... if you run a muffler? I'm affraid I'd fall asleep at the wheel!

 

Yeah right...the ride of my truck will still keep me awake

Chris

 

The BD dual turbo down pipe ends just before the transmission cross member. The factory exhaust uses a pin to secure it to the cross member and this pin is missing with the MBRP. Without the exhaust clamped there, when the engine torques over, the down pipe will stress the front of the muffler and crack it. Here is a salty picture of my BD exhaust showing the down pipe where it connects to the pipe before the muffler. The band clamp I used has a pin to engage the rubber factory mount. I decided to make this modification after hearing the exhaust pipe rattle against the frame when accelerating.

 

Thanks Dave.
Got the 5" installed. Surprisingly quiet with a nice 'deep throat' sound.... Just right, IMO.
About the same as my 4" with the leak!

RJ

 

Ain't it great??

I can't wait to get mine built...but I have a while before I do

Chris