Ansa, DTM, PIM Mufflers

I have the PI mufflers and like them. Reasonably quiet? but healthy at idle and a nice sound when you open it up. At the time (2 years back) I went the PI because they had the biggest inlets I could find. 2.5 inches. I was able to run 2.5 from the headers (Pi as well, the "big throat" headers on the same link you have a little further down the page) to the mufflers. One of the mufflers in your post is 2.25 inlet and the other has the 2.5 inch inlet. I agreee with the theory that says anything you can do to make the engine breathe better is a good thing.The PI's look good and held up well.

Shotgungrooms has (or had) them on his car as I remember and maybe he will chime in as well.

Ed...

One option is to open up your stock ANSA mufflers. It is low cost solution that works and looks great.

Mike

Yeah the problem with the stock ANSAS is that they still have the little 2 1/4 opening and the smaller outlets. Even if you gut them and redirect the flow they are still limited by that diameter. Plus if I change my mind, I would like the stock mufflers intact and be able to sell them if someone wants that stock look or if I decide I want to go back. Would rather cut up some Ebay specials if need be, and I think that is the route I'm going to take.

I'll let you guys know once I get them mounted and hopefully run a back to back dyno session with them and a few other tweaks.

My ideas on muffler design, now these are my design ideas, but is you can take a stock muffler, have a 2 1/2" pipe made for it. On the inside I would totally remove any baffles, and Installed a perforated screen material to hold a 1/2" mineral wool around the outside perimeter. Instead of baffles you use two "V" shaped pieces of sheet metal half the height of the muffler internals. Place these in front of the muffler inlet, the wide part of the front "V" away from the inlet, the other "V" would be away from the front "V" by say a inch or so.
If you look at some of the mufflers manufactuers websites they will show you cut aways of the re mufflers. This can give you some very helpful ideas on how to design a muffler.
Some of the points for these new designs.
1) The perforated sheeting and mineral wool, will help deaden the sound waves by traping them inside of the muffler and the wool.
2) The "V" shaped "baffles will point the soundwaves into the dead area between the "V"s and help kill sound without seriously hurting the flow of the muffler.
Some of the mufflers I have seen use this design now. The first one I saw had the perforated skin made into a almost reversed hourglass to help bounce the soundwaves inside of the muffler. But remember the shape of the "V" baffles and the shape of the perforated skinning will alter the sound the muffler will make, so a trial and error temp muffler that can be easliy altered would be needed to get to the sound you want.
Now you know my thoughts on the design I had been thinking of building.
Jeff