I'm soon to get my exhaust repiped from the header back. I wanted to use 2 1/4 piping from the catalytic conv. to the resonator and to the muffler. But I was wanting to hide the 4inch round muffler under the car and run 3 inch piping out the muffler to the back of the car.

My question is 3inch piping too big to use from the muffler out on a Dseries. Or should I use 2 1/4 piping and just put on a 3 inch tip at the end. There will be about 2 feet of 3inch piping from the muffler.


Modified by AnToNy at 6:46 PM 6/29/2005

 

2 1/4 is plenty big for a d.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chowmien &raquo;</TD></TR><TR><TD CLASS="quote">2 1/4 is plenty big for a d.</TD></TR></TABLE>

I'm asking if 3inch is too big to come out of the muffler. There will be about 2 feet of 3inch piping from the muffler.

 

There's no real point of having bigger piping from the axleback to the muffler tip. Keep it 2 1/4 all the way back.

 

if u go 3 inch you will lose back pressure which means you will lose power..the only time you should go 3 inch is if your turboing a car...2 1/4 is plenty

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SPNFEDEJ &raquo;</TD></TR><TR><TD CLASS="quote">if u go 3 inch you will lose back pressure which means you will lose power..the only time you should go 3 inch is if your turboing a car...2 1/4 is plenty</TD></TR></TABLE>

2.25 is more than enough for a D series

 

you will need no more information as these two gentlemen are correct. 3 inches is generally over-kill for a lot of 8 cylinders.

 

Yea...2.25 is fine....Don't go with the 3" that in my opinion is paying someone to take horsepower away....

 

3 out of the muffler is fine.... think about it, the only part that benefits from backpressure is the engine. After the headers reduce it to 2.25, the engine can't tell the difference, if the pipe widens out to 3" after that. That is, if we're not counting the muffler in the system. Now the muffler and cat add to backpressure because of turbulence and probably less flow than a 2.25" pipe allows. But after the muffler, there's no reason you couldn't go with 3 inch piping, assuming that's what you like. Be advised that if the 3 inch piping is coming directly out of the muffler (instead of 2.25 out, flared to 3), it will lower backpressure a nominal amount, but *could* also cause you to have a much louder exhaust.

 

Buy a turbo, go 3 inch. problem solved.

NA = 2.25.

Horsecock mufflers suck

 

stay 2.25" all the way through. your exhaust only flows as well as its weakest point. putting a larger tip on it will have sort of a megaphone effect and actually make it louder.

 

Thanks guys, for all the replies. I was almost positive I would lose some backpressure if the piping got too big out of the muffler... I will just use 2.25 out of the muffler and throw on a 2.3-3inch polished tip. Making my own Buddy Club Spec II system, except with muffler to quiet the sound a little bit.

 

stock exhaust+NOS=real horespower!

jk- 2-2 1/4 would be plenty for most any application unless your running 400hp turbo car