1-in/2-out Muffler input needs alteration, Any advice ? Options

[Literati914]

I have a set of 4 into 1 stainless headers that I want to connect up with an old stainless steel 1in-2out Tangerine muffler. The muffler was obviously not made for this header system but they are not that far off either. Well a little is a lot in this case I guess.

I have a MIG welder and thought I’d buy some self-shielded stainless wire (rather than invest in a whole tank of gas), and try to fix the gap. If nothing else I figured I could tack up a solution and let a real welder finish it (if blowing holes became unavoidable).

I’ve found that the tube exiting the muffler is apparently made up of mild steel at the flange (magnet sticks strongly), then the curved mid-section of the tube is a low carbon steel (magnet sticks BUT NOT strongly), then the very short part is all stainless as is the rest of the muffler (magnet does not stick).

I’m looking for suggestions as to where you guys would cut, maybe good only spots to buy pre-curved stainless or what to search for. General suggestions would be appreciated. Part of wanting to take on this task is that I’d like to add to my welding experience if I can. Here are some pics of the project:

[Literati914]

Sorry but I have to ask, are you not defeating the reason for a header in the first place but choking it off at the muffler inlet pipe? Maybe you could knock a piece of wood into the inlet pipe and run a hole saw to get a bigger hole in the muffler and then weld in a pipe that is closer to the diameter of the header outlet? Just curious about the reduction

I think the pics are accentuating the pipe diameter differences more than the reality. I'm getting a consistent 54mm OD at the muffler-in, and throughout ALL of the stainless curved area... and 64mm OD at the muffler flange area AND the header flange are. So that's 2" and 2.5" ... is that an uncommon reduction? I've always heard a little backpressure was a good thing (IMG:style_emoticons/default/confused24.gif)

Actually, the inexpensive collector is far from optimized. The pipe going into the flange is way too big. Other than trying to make the reducer smoother, I don't think there's much to be gained by enlarging the muffler inlet.

Chris, can you elaborate on what you mean by "inexpensive collector" and how it could be optimized? I figure that comment was not necessarily a slight on the header unit, but I'm confused by the statement and would like clarity. I can change any/all of it .. and now's a good time for it. So if you have a suggestion, I'd like to hear so I can better consider how I handle it. I thought of scrapping the entire curved muffler pipe and starting over with ALL stainless, but honestly if it equals little to no gain, I don't see the point. Also, I was really trying to keep it simple and not buy a whole bottle of special gas for stainless as it's just a small job (was gonna get some Blue Demon self shielding stainless wire). All thoughts appreciated.

[Shivers]

Sorry but I have to ask, are you not defeating the reason for a header in the first place but choking it off at the muffler inlet pipe? Maybe you could knock a piece of wood into the inlet pipe and run a hole saw to get a bigger hole in the muffler and then weld in a pipe that is closer to the diameter of the header outlet? Just curious about the reduction

I think the pics are accentuating the pipe diameter differences more than the reality. I'm getting a consistent 54mm OD at the muffler-in, and throughout ALL of the stainless curved area... and 64mm OD at the muffler flange area AND the header flange are. So that's 2" and 2.5" ... is that an uncommon reduction? I've always heard a little backpressure was a good thing (IMG:style_emoticons/default/confused24.gif)

Actually, the inexpensive collector is far from optimized. The pipe going into the flange is way too big. Other than trying to make the reducer smoother, I don't think there's much to be gained by enlarging the muffler inlet.

Chris, can you elaborate on what you mean by "inexpensive collector" and how it could be optimized? I figure that comment was not necessarily a slight on the header unit, but I'm confused by the statement and would like clarity. I can change any/all of it .. and now's a good time for it. So if you have a suggestion, I'd like to hear so I can better consider how I handle it. I thought of scrapping the entire curved muffler pipe and starting over with ALL stainless, but honestly if it equals little to no gain, I don't see the point. Also, I was really trying to keep it simple and not buy a whole bottle of special gas for stainless as it's just a small job (was gonna get some Blue Demon self shielding stainless wire). All thoughts appreciated.

If Chris says it's fine, I'm no expert. I'm thinking flow:

"The first question is at what cfm do we experience 120ft/s in 2" and 2.5" pipe? We calculate the area of the pipe, convert to sq.ft. & seconds to minutes, and after doing the math we find the answers are 157cfm for 2" pipe and 245cfm for 2.5" pipe (the Engineers will find both air flows at Mach 0.11)."

I had this in my head that loosed my fingers. Sorry (IMG:style_emoticons/default/confused24.gif)