Does anyone have a 12a bridgeport with dual piping all the way back? I am considering making my header be uncollected all the way back and over the axle with a couple gaspaks or straght-through muffler of some kind in place of the stock muffler location. The piping would run side by side all the way back.

I have rode in a '80 mod'd engine with uncollected header that had pipes going to a couple motorcycle aftermarket mufflers(for each pipe) and sounded reasonable(not all that loud). He had it so they came out the side of the passanger side with both pipes flush with the rocker panel on the side. It sounded very cool and had good response with a mod'd Nikki carb on it.

THe reason I want this is that backpressure is supposed to be kept low as possible with a bridgeport, and having them collect will cause the scavanging to be tuned in a certain rev range and hurt the other rpm ranges for the most part. Where as a uncollected header should not have any (range) limitations only the restriction of the air pressure outside the pipe as well as pipe diameter are the limiting factors.

Currently I think a single pipe with 2-1/4" is probably a little restrictive and the muffler isn't helping either really.

Thoughts?

 

Anyone?

 

You might want to put several presilencers in there too... no glasspacks either, all-steel only.

 

True dual exhuast tends to be a road race setup.
You'll lose a bit of low end for top end in this setup.

Note: It'll be loud.

 

I thought it was true duals that had a broader powerband than a short-primary setup...

 

Wacky DAMN a single 2 1/4" that is even too restrictive for a smaller port than bridge. I am running 2 2" header primary collecting to a single 2.5" in a stock port 12A.

Wacky the setup you describe I think would be awesome...Search around australian sites. I once read about a street Bridge port setup where a guy was runing true duals with about 6 mufflers or something like that...it sounded ok not to loud and it was non-restrictive at all, very streetable.