Hollow cat and a Supertrapp?

[thrown_hammer]

What do you think? If I hollow out the cat and go with a 10" Stainless Supertrapp. If I had a muffler weld up a 30 deg bent pipe with a 3 hole flange the muffler would exit in the stock location. Noise isn't an issue with me but what about power? Would it be less restrictive than the stock muffler? It would also weigh MUCH less than the iron hotdog hangin on there now.

[69911e]

Here is a quote from the following link:
Note that supertrapp disks are EVIL! The factory sport muffler is real close to open supertrapps in top end power, and even better for autocrossing (though it is a lot heavier...).

Dyno results are also at the link.

http://www.analogman.com/911/911eng.htm

[Gordo]

69911e makes a very good point. Supertraps are much more restrictive than you would think. When I pull enough disks out to make 90 db noise limit It appreciably chokes down my performance. This is with 2 traps running on 1 5/8 id headers. I would imagine a single supertrap would be VERY restrictive. Weight savings is great but if you are choking the engine it just does not pay off.

Best, Gordo.

[Joe Bob]

To get the best flow, there are going to be a LOT of discs for a single and it will be L O U D ........

I currently run twin traps, with 12 discs in each on my 3.6. It barely 92 dbA........

[thrown_hammer]

Well POOP! What is a noisy low cost alternative that won't be too restrictive? I want to keep my heat exchangers. So it would havr to be either single in/ out or single in / dual out.

[1fastredsc]

Well if noise isn't a problem, why not weld up decent glass pack?

[Joe Bob]

Originally posted by thrown_hammer
Well POOP! What is a noisy low cost alternative that won't be too restrictive? I want to keep my heat exchangers. So it would havr to be either single in/ out or single in / dual out.

Well for better flow, get some SSIs or stock 73 and earlier heat exchangers....bolt dual trapps to them.....

[k9handler]

supertrap

[69911e]

I am almost certain the poor dyno results in the above link were using dual supertraps....

[thrown_hammer]

Mike...Key word..."LOW COST" If I could afford SSI's I wouldn't be looking at $125 mufflers.

[Joe Bob]

Then find some early HEs or some cheap headers,,,,real men don't need heat.....COLD, put on a jacket....

[Joe Bob]

PS....I know a guy with some headers that have Supertrapp flange ends already welded on. All you need are the discs. $100.00.

[1fastredsc]

"Then find some early HEs or some cheap headers,,,,real men don't need heat.....COLD, put on a jacket...."

Well put mikez!

[thrown_hammer]

Mike you have a PM!

[masraum]

you could leave the cat and just add that 30 degree bend to the back, that's what I did. No muffler, just a cat.

[thrown_hammer]

Steve I pulled out all the steel wool already so all thats in there is the ceramic. How does yours sound?

[Hetmann]

Originally posted by mikez
real men don't need heat.....COLD, put on a jacket....

Not every one lives in Santa Barbara.

[PeteBrown]

Here is what you need. It's a cat-bypass pipe that has been cut down in the back so an Edelbrock RPM Series muffler could be attached. A small tail pipe with a 30 degree bend was welded on end with a rubber hanger that attaches to the bumper screw. It's LOUD, weighs 25 pounds less than the cat-sausage muffler combo and is free flowing.

[PeteBrown]

Also, the good doctor, Steve Timmins is now offering a similar combo for $300-400. I forgot the exact price but the pipe is on his website.