Would a 3" diameter inlet/outlet muffler work on a SC?

[oregonmon]

Saw a guy selling two Dynomax Ultraflow Welded SS mufflers that are a straight through design for a good price but they are 4" diameter and 3" inlet/outlet. Total length is 23".
Would something like that work. Actually just thinking about a cat bypass and sport muffler for now for a low budget mod.
Please don't recommend the SSI's, because I know they are a great upgrade, they are so expens

[911Freak]

What kind of setup are you considering attching these to? Stock H/Exchangers?


I'm sure other more knowledgable guys will chime in on this but isn't the ID of these poss. to big, and thus hurt performance?

FWIW I run, for now, stock H/Ex with a Cat by-pass, thru a 1 in 1 out B&B Muffler with a giant 4.5" tip... very happy with the performance gain and the tone..
But as soon as do my 3.0 to 3.2 rebuild I plan on running a set of Euro Headers with custom fab'd twin high flow Cats and a 2 in 2 out muffler...Incl as per Steve's suggestion: cross over pipe as I will come no where near 8000+ rpm's....

[oregonmon]

Thinking a little outside the box, I know it's dangerous. But what about this. Have a exhaust shop fabricate piping coming off the driver's side heat exchanger and the crossover pipe (remove the cat) and run the two mufflers side by side in the space where the cat would go and a some pipe and two muffler tips exiting? Did I make that clear?
Enough room? No smog testing here by the way.

[oregonmon]

Originally Posted by 911Freak

What kind of setup are you considering attching these to? Stock H/Exchangers?


I'm sure other more knowledgable guys will chime in on this but isn't the ID of these poss. to big, and thus hurt performance?

FWIW I run, for now, stock H/Ex with a Cat by-pass, thru a 1 in 1 out B&B Muffler with a giant 4.5" tip... very happy with the performance gain and the tone..
But as soon as do my 3.0 to 3.2 rebuild I plan on running a set of Euro Headers with custom fab'd twin high flow Cats and a 2 in 2 out muffler...Incl as per Steve's suggestion: cross over pipe as I will come no where near 8000+ rpm's....

For now staying with factory HE's.

[oregonmon]

So I've stumped you guys?!

[HarryD]

Ryan,

If I am not mistaken too lagre diameter will kill your bottom end by effectively reducing the scavenings effect.

I think there may be some threads here on exhaust system design. It would pay to take a look. Several have pointed out that it is difficult to improve the factory design, most settle for no lost perfomance in the quest for sound and looks.

[3.2 CAB]

You could have pipes as big as garbage cans, if you have the engine set-up and adjusted for that. Those 1000+HP AA dragsters have short open pipes, but they are designed to be that way. It does not seem to me that you could not adjust some for the difference in back pressures. Just a thought.
I have test run my engine with just the cat, and it did not sound as obnoxious some of the ricers and their fart pipes. Good luck!! Tony.

[porsche930dude]

That would be as loud as a cat delete with a muffler delete. I ran a 2 1/4 glass pack with a cat and it sounded great and ran great too. Then i switched out the cat for a euro pre muffler and the glass pack was way too loud because of the totally straight through design. Iv switchd out the cat for a modified muffler and it sounds much better but i think i may tear into again for a little bit more flow and sound eventualy. Building a custom exhaust for a porsche is very tricky and its easy to not get what you want. I can tell you i doubt youll like that setup