Exhaust advice sought

I would like to tame the sound on my Scorpion. Above the stock muffler I have, where there is a straight pipe with 3-bolt flanges at each end, I want to add a resonator or muffler. I want to reduce overall noise as well as the boominess in the exhaust. On long trips it's still pretty loud and I like to converse with my passengers when I have them. And hear my music when solo.

I have found a couple of options that would work.

Option 1 is a glass-pack style tube item that will fit and not take up much room, 4" dia., 12" body. My worry is that it won't help much as option 2:

Option 2 is an oval muffler with centered inlet and outlet, about 3-1/4" x 7-3/4" x 17" body. I think this would do better at reducing noise but costs more. I have measured carefully and this will fit above the muffler where a CAT normally fits.

My other question is about pipe diameter. The pipe I'm replacing is about 1-5/8" I.D., where the rest of the system is 1-3/4" I.D. Would it be a good idea to use the 1-3/4" version of either of the options vs. the 1-5/8" version?

Would my money and effort be better spent just replacing the stock muffler with new? I am doing the welding myself, thanks to Tony.

My vote would be the more expensive option unless a glass pack is ultra cheap in which case I would creep up to the solution (given that your labor is "free") i.e. you would do the one solution, test and decide if you wanted to move to the next... You can always cut off the flanges and weld them onto the oval muffler. I think you will be surprised by the change.

Another alternative and clearly more expensive is to fit a new catalytic converter. A new one will not be very restrictive, they do a great job of managing noise and given that you are running a fuel injected motor now, it would be able to finish cleaning up the exhaust. Just a thought, I know its anathema to most for performance but it likely wouldn't meddle with it negatively.

I would make the pipe diameter 1.75" consistent throughout.

kmead said:

Another alternative and clearly more expensive is to fit a new catalytic converter. A new one will not be very restrictive, they do a great job of managing noise and given that you are running a fuel injected motor now, it would be able to finish cleaning up the exhaust. Just a thought, I know its anathema to most for performance but it likely wouldn't meddle with it negatively.

I would make the pipe diameter 1.75" consistent throughout.

Click to expand...

I'm considering this as well, I can get a modern aftermarket CAT for $70 or less. I worry that something might go wrong with the F.I. and kill the CAT though, and they're smaller than the oval pre-muffler option I'm leaning toward.

I'm still planning on trying this on my X with header:
http://xwebforums.com/forum/index.php?threads/24703/

I ended up ordering a 4" dia. muffler from Summit that I'll weld into place where the CAT used to be. Arrives today according to UPS.

I drilled holes in the muffler to get the CAT pellets out from when the CAT previously failed. Now that I have a MIG setup I can mend stuff like this, it's fun!

Would it help to cut open the muffler and stuff it with SS shavings (packing)? It sounds to me it's just a hollow shell at this point, with some baffles that support the pipes inside I think. Has a Lancia name and part number on it. I guess my real question is, would this help? Might be hard to say and depend on how it's built.

Results...

OK, I'm no welder, but I'm getting better.


The test drive before retiring to watch Herbie the Love Bug with my daughter sure seemed like it made a small difference, mostly in the boom factor. Sounded more tuned, metallic. I think I'd most happy with a new muffler for this reason.