Printable Version of Topic

Posted by: retrotech Dec 14 2004, 08:29 PM

How much performance influence, if any, would the length, and diameter of the 2 exhaust pipes, on 911 Sport muffler? Would increasing from 2" exits to 3" have any effect?

Thanks,

Retro

Posted by: ! Dec 14 2004, 09:51 PM

Depends on the motor......some injected models like back pressure. Carbed models with the right cam will wake up and appreicate a high flow....at the detriment to low end torque.

Posted by: retrotech Dec 14 2004, 11:12 PM

I didn't think by the time exhaust passed through heat exchangers & muffler, that the tail pipes would effect much. The engine is 2.8 carburated 46mm Webers.
So you think it will effect my low end torque?
Thats not what I wanted to hear, I already bought these nice 3" Stainless pipes to weld to Sport muffler.




Retro

Posted by: sixnotfour Dec 15 2004, 01:39 AM

Do like the import guys weld the bigger pipe over the smaller one. Make the inner one at little shorter. Or make it into a cookie cutter. Big stainlees and keep yur torque

Posted by: retrotech Dec 15 2004, 10:58 AM

Thank you for that suggestion, that is exactly what I am going to do! I appreciate the suggestion.

Posted by: ! Dec 15 2004, 11:04 AM

That's one way....

btw, it also depends...like you mentioned on the whether you are running headers, HEs and in what style.

Posted by: retrotech Dec 15 2004, 11:10 AM

Factory 914/6 heater boxes, that I will change to headers in the spring. Does that change the opinions?

Posted by: Eric_Shea Dec 15 2004, 11:49 AM

I went with 2"

I don't think there's a difference between the factory heat exchangers and headers other than they have the heat boxes wrapped around them.

Once you do the Sport Muffler mod, there's not much in the way of baffling to slow you down so back pressure may be an issue.


Attached image(s)

Posted by: retrotech Dec 15 2004, 03:18 PM

That is why cutting the 2" tail, 3" shorter, and install 3" stainless shield over it?

Posted by: retrotech Dec 15 2004, 03:27 PM

Sorta like this, but with deeper rear skirt, and when 2" pipes are cut back 2" they won't show.


Attached image(s)

Posted by: scooter311 Dec 15 2004, 03:46 PM

Hey, anyone here do that to a 2.0 (4cyl) muffler?

Retrotech, that's exactly what I wanna do for mine. I was thinking I need a banana style/Bursch to hack


Hmmmm?

Posted by: J P Stein Dec 15 2004, 03:52 PM

I went with one of these.... because of this. http://www.triadwestperformance.com/images/CRANEY_TXT.htm


Attached thumbnail(s)

Posted by: sixnotfour Dec 15 2004, 05:18 PM

If someone wants a Triad like JP.s I got one For Sale 140.00
Used about 3 months. Been sitting around 2 years.

Posted by: ! Dec 15 2004, 05:21 PM

You have a PM