Free stainless steel sheet + neighbor's new TIG welder + learning how to TIG weld = homebrew muffler time
Vehicle in question is a 7.3 Powerstroke van. I'm doing a 4" turbo-back exhaust. I would just go straight pipes but since the van is a big resonant box I think it will need some help to keep it a little quieter.
How would you go about constructing a muffler that doesn't restrict but cancels at least a bit of the pulses?
You could do a chambered design that reverses the flow. I did that for my racecar and it worked well.
Build a cylinder or any other shape. Find someone with a lathe or mill and see if you can get some stainless turnings or swarth. Pack it in there. Not too tight. Put a tube in and a tube out. Ideally don't line them up directly (or at all). That should cancel out a bunch of the waves and reduce a lot of the resonance.
Find a cutaway picture of a Flowmaster muffler for ideas.
Maybe try a chambered exhaust? Just wrap a length of pipe around the exhaust outlet, bang some dents into the pipe, then weld it on.
I knew a guy who use to build aluminum exhaust's for his cars, (he was also good enough of a welder to weld aluminum cans together) but he would just take a pipe and perforate it then tack 3 or 4 supports to it tack those to sheet aluminum. Make the can and before he seem or plug welded the sheet into a full canister stuff it with stainless steel wool.
DeadSkunk wrote: Find a cutaway picture of a Flowmaster muffler for ideas.
I have... The thing that scares me is that I haven't liked the sound of the Flowmasters I've owned.
mw wrote: Build a cylinder or any other shape. Find someone with a lathe or mill and see if you can get some stainless turnings or swarth. Pack it in there. Not too tight. Put a tube in and a tube out. Ideally don't line them up directly (or at all). That should cancel out a bunch of the waves and reduce a lot of the resonance.
I like it. I was always concerned about "packed" mufflers degrading over time, but stainless lathe "hair" should work great.
can you make your own muffler bearings too?
Sorry, could not resist
mad_machine wrote: can you make your own muffler bearings too? Sorry, could not resist
Naaa I purchas them here 
http://kalecoauto.com/index.php?main_page=product_info&products_id=48
touche'
You'll need to log in to post.
