Do you think it will work if I drill a bunch of holes in a 2.5 OD 1/8" wall thickness pipe, wrap a bunch of stainless steel wool around it, and cover the outside with a 4" diameter pipe? I heard or read somewhere that some people have had success with home made "presilencers" like this. Any thoughts on hole size or spacing? I'd like to use this with my NA 20B.

Magnaflow already make that for you, available from Summit for $50-65, depending on length. All Magnaflow mufflers are stainless-packed.



For a few bucks more, they also have a 6" outside diameter version.



That is inexpensive enough to make it worthwhile to buy instead of build. You'll probably have an entire day in front of the drill press just drilling holes in that pipe.

pack it with lava rock instead

You can buy perforated tube, save you from drilling holes.

I made some before exactly as you were thinking of building yours. They worked very well. Its a lot of work drilling all those holes.

Or you can buy perforated sheet from Mcmaster.com and roll it into a pipe whatever size you want.

I found this easier than finding perforated pipe.

It's hard to roll perforated sheet because it kinks at the weak points where the holes are.



How do I know this? https://www.nopistons.com/forums/pub...1047683561.gif

i love my magnaflow resonator. best exhaust mod i did to my sentra. the one i had was 32" long, 3"in/out and 6" diameter

This topic generated some discussion. https://www.nopistons.com/forums/pub...IR#>/smile.gif



My first choice was the Racing Beat 2.5" presilencer. http://www.racingbeat.com/resultset....rtNumber=16408 Can't afford that right now.



The second choice was to seek out a 2.5" tube style muffler with similar features to mimic the presilencer. Thanks heretic.



Third choice is to attempt to make my own. I have a dead Rotary Engineering glasspack that is hollow inside. All the glass stuff must have blown out years ago. The outer shell is good. The inner pipe has gotten loose. It's only 2.0" and I have no problems with gutting it for a 2.5" pipe. I just need to determine whether my time is worth 50-60 bucks to stand at a drill press all day. Then of course there is the stainless steel wool that must be sourced and purchased. Finally there is the welding.



I'm left wondering how well it will work when finished.



sand121, can you give me some details like hole size, spacing/distance, pipe diameter, what you installed it on, what was the rest of the system like etc? Thank you.

anyone have any good reading about mufflers?