Aftermarket mufflers???

[igya]

My '85 has a left muffler that's rusted out on it's tip and rather than run down another, I'd like to install a set of 1200 H-D mufflers that are straight-through with surrounding baffles. I'm wondering if not enough back pressure could be an issue. Anyone done any homework on aftermarket exhaust?

[Gearhead]

A few have adapted other mufflers. something about the angle of the pipe at the header joint is a little unusual. One guy here made his own mufflers from straight pipe which he made some sort of baffle for. I don't think he had to change the carb settings.

 

Jeremy

[igya]

A few have adapted other mufflers. something about the angle of the pipe at the header joint is a little unusual. One guy here made his own mufflers from straight pipe which he made some sort of baffle for. I don't think he had to change the carb settings.

 

Jeremy

 

Yep, that angle is a real bugger bear. I can deal with that though. I know that when I raced with high performance engines, the right amount of exhaust back pressure was essenitial to prevent burned exhaust valves and holes in pistons. I just don't know if straight through pipes could cause that problem with the Ventures.

Thanks for your response!

C.W.

[Gearhead]

Backpressure affects the jetting requirements, but the question is, does the change you want to make SIGNIFICANTLY affect the requirements? In theory, and engine likes as little backpressure as possible. Could the backpressure requirement you are referring to have to do with creating a lean condition?

 

I know that a bunch of guys here have installed Mac pipes, and some have Jardines. I don't think they are straight thru, but probably have a perforated baffle with one diverter plate in the middle. The guy I referred to who made his own - that should be here somewhere, but I couldn't find it in a quick search. We had a big server crash a couple years ago; maybe it was pre-crash and now gone.

 

Jeremy

 

Jeremy