2nd Gen JCW Most liked posts in thread: R56 JCW - Build Thread - New Set Of Pipes

Thanks all, for a split second I was thinking 4-1/2", but that would be a little much. The size of each canister will determine how much sound absorption / cancellation will be achieved with the exhaust note. The bigger the "room" so to speak, the better the exhaust gasses will be allowed to expand before exiting the two baffled chambers. I will always be able to make them louder by reducing the chamber size with my inserts, but the two muffler's capacity will always be determined by their initial size.

Rixter, good point on the space between for cleaning. Right now the mockup is at 1/4" space. I'm thinking I'll be able to pull a rag through that and get enough cleaning force to knock off the grime. I could probably open it up to 3/8" space with no problem. I'm trying to leave a little gap on the right and left sides of the muffler so there won't be any contact with the bumper skin, bringing vibrations into the cabin.

With the 4" mockup tips sitting on the kitchen, they look huge, but after attaching them to the MINI for a visual, they look OK.

So I'm settled on 4".

Thanks Guy's.....

Chuck

 

Good suggestion on the angled tips. I'll go ahead and tack weld the mockup together and do an angle cut on the tips, I'll match the same angle as the JCW tips. Then I can flip the mockup..... showing the angled tips or the square cut tips and get your input on which looks the best.

Thanks, you's guy's.

Chuck

 

Well.............
I guess I could make one side bias cut and the other side square cut.

 

Thanks for the kind words.... I've always liked making things with my hands. Coming to work every day never seems to be a choir. I have great employees and loyal customers, what more could someone want?.

The original exhaust will be packaged up and stored back in the corner of the shop for the eventual day I sell my MINI.

 

Just received my SS flex joint from TH Motorsports. Price $34.57

As suggested by Keith Huevo, this design creates less exhaust turbulence than the corrugated flex joint.

Thanks Keith for the suggestion.

Chuck

 

OK.....
I've come to a kind of crossroads with part of the design of my custom exhaust.

At this point I'm currently staying with the stock downpipe during the warranty period. For the most part this experimental exhaust from the cat back will be a straight through exhaust. I'll venture to say the most restrictive part will be the stock downpipe, with cat being the biggest contributor to exhaust back pressure. I chose to go from the stock 2-3/8 tubing size to 2-1/2, in an effort to reduce back pressure and have a muffler design with baffles that can be easily pulled and changed to adjust the sound level. Reduced backpressure should allow the turbo to spool up faster.


So todays question has to do with the effects of exhaust backpressure on a turbo charged engine....

If I had a way to adjust backpressure from say stock to wide open, what might I expect to see in the way of change?

Any thoughts on what might be expected?

Chuck

 

No, everything is still they way it came from the factory.