Side exit project!!

[Lee]

Yep. Thats why they ended up with the separate wastegate as it is easier to fit a 3" and a 1.5".

[Audi_CQ]

@ Audi CQ and all the other folk here - if you're using single 3" in places, you get the same cross section (approx) from a pair of 2-1/8" pipes, shouldn't really need 2-1/2"? Even more clearance and more routing possibilities?!!

Ok, now for a "cat among the pigeons" question: what use (if any) is a separate wastegate exhaust? I can't think of any, but I've seen some Rice Rockets with exactly that sort of installation.

__MDC__

As exhaust travels backwards it cools and "shrinks" so lesser pipe area can be used.
I start with a 3.5" downpipe ("flattened" a bit from where it goes under the driveshaft to get better clerance) with a separate ~2" wg-pipe. (Separate pipe to avoid interference and to get more area.) . This is about the same as a 4" single DP. Splits to 2x2.5" and joins further back to a 3" single pipe with a single 3" silencer at the back. The system does it's job and sounds really nice without anoying resonance (right spelling?)

Cheers,
Roger