Exhaust Gurus Please

[audijunky]

the VW does make more of a hissing noise now though when getting on it.

[xschop]

"Three 1/3" holes be significantly more than a single 1" hole."

No, actually 3 x .333" dia. holes will be 1/2 the area as the 1" dia. hole. So we were both confused. I will machine a single 1" hole set and a set with 4ea .5" to match the exit area. I think the butterfly-washer idea is not very acurate like AUDI said there is to much exhaust/sound getting past the outter wall. Could I stuff some fiberglass in there as well?

[audijunky]

I think your supposed to use steel wool??

[xschop]

steel wool?

would make sense, but would rust out quick/easily. I can get stainless wool but not as compact as regular steel wool (00 or 000)....good idea tho.

[Crazcnuk]

If you really want to experiement, I would cut back the inner pipe about 1"-1.5" deeper into the outer pipe. Then put a 4" (or whatever the ID of the outer shell is, and put the holes in that towards the outside of the larger plate.

Sound is controlled by reducing the straight-thru parts, and pressure is controlled by orifice diameter or gas excape routes, which don't have to be straight.

So for this one you would want that inner pipe to come out directly into a solid wall, with enough space as not to restrict, then the holes will allow the gases to escape, just not straight out.

This also gives you a lot more room to try lots of little holes...

Derwat, if he would ever post here, could tell you more. He has a home-made muffler on his BMW 750iL

[audijunky]

check this out
http://www.coneeng.com/mufflers.html

[xschop]

exit tube

Hey Crazy, I was just thinking which tool I can get back there to do just that. I will probably cut four lengths down the outter tube with aviation snips and bend the metal back to add this chamber. Guess since you're a GURU now, I must obey the chambers I originally cut off also alternated like you said, so this is where the sound is muffled. I chose these slashed-curved tips to be able to point it towards the ground to get rid of some of the sound like I did on my S10 with the Vette motor, straight pipe to flowmasters and NO CATS, I love oklahoma, no smog referee here

[Crazcnuk]

If you want to make it like the Flowmaster mufflers, you would make a cone. The cone would point the direction of (exhaust)travel.

You make the wide end of the cone about 1/4-1/2" smaller diameter than the outside tube, then just add some tabs to the cone that allow you to put screws to hold it to the outer tube. Once your satisfied you can rivet it on, and put your down tubes on.

The exhaust then comes out of the inner tube, into the narrow part of the cone and has to do an S turn to go around the outside. This can give you the requisite space after the inner tube without having to cut anything as it sits now.

Flow master mufflers do this, and they put in as many chambers, each with it's own cone, baffle setup, until it gets to your desired quietness.

[xschop]

uhh

I'll have to really think that one over. I am going to cut back that inner tube and then work with the two diff. type spacers and see what's the deal