S pipe

[longviewbird]

OK i did a search and did not see anything with what i want to know. When ya"ll cahnged your exhaust to a cat back did you change the S pipe and I pipe to 3" or just the I pipe. Thanks

[GregWS6'01]

It depends on the system bought. Most Cat-Backs contain everything from the Exit of the Cat to the muffler. That's the I-pipe, S-pipe to go over the rear axle, and muffler.

Most of the Cat backs have the I-pipe and S-pipe made into one piece....Different systems may be set up different

[Silver2000V6]

It depends on what you are calling the s-pipe. Some people think it is the pipe that goes over the axle, and som think it is the pipe that goes from the cat in two 90 degree bends to the i-pipe. I think all cat-backs are going to have the i-pipe, including the over the axle pipe. Not all of them include the s shaped pipe between the cat and the i-pipe. I have the edelbrock cat-back and I had to have that pipe custom bent at a Midas.

[GregWS6'01]

if it doens't have all the pipes then it's not a true cat-back

[Backfire]

It depends on what car the system is for. I bought an exhaust system off of a 2001 Z28 and because the y pipe for that system ends further downstream in the system than my original s bend section, the catback doesn't have the bend, only the straight section before the axle hump. If that makes sense. If you buy a system for an earlier V8 with a single cat, it should bolt up to the cat.

[96 T-Top Bird]

<blockquote>quote:</font><hr>Originally posted by GregWS6'01:
if it doens't have all the pipes then it's not a true cat-back<hr></blockquote>

My flowmaster cat back came w/ an i-pipe but not s-pipe.

It said it was a catback exhaust. Not sure, i just have the I-pipe that goes over the axle and stuff. The pipe directly out of the cat is still 2 1/4 and it goes into the 3" i-pipe.

I thought all systems consisted of that arrangement.

[shortdog273]

I Agree with 96 T top. Some of the catbacks don't have the "S" shape going into the cat, but some fit directly on the cat. The "S" pipe is NOT the pipe that goes over the axle. For those who wanna get rid of that "S" pipe, order two 45 degree mandrel pipes from jcwhitney. It costs around 40 bucks. The size is up to you.

[longviewbird]

ok now my second question is when i got up under my car and looked today, my pipe is welded to my cat. I can't bolt anything on. What should i do?

[shortdog273]

You most likely gotta get your new pipe welded on, but I'm not sure.

[GregWS6'01]

S-pipe is what goes over the axle. If you ahve another set up then you don't technically have an S-pipe. You just have a fully welded I pipe that goes to your exhaust. There isn't an S-pipe before the Cat. The Y-pipe comes from the Headers and goes to the Cat inlet. Why would you have an S-pipe before the Catalytic Converter????? Can't think of reason why you'd need a pipe bending all over the place there when it'd be just a straight shot through the Y-pipe to the cat. The S pipe, is technically not an S. It's a hump to clear the area of the rear axle.

[HAZ-Matt]

<blockquote>quote:</font><hr>Originally posted by shortdog273:
Some of the catbacks don't have the "S" shape going into the cat.... The "S" pipe is NOT the pipe that goes over the axle.<hr></blockquote>

<blockquote>quote:</font><hr>Originally posted by GregWS6'01:
S-pipe is what goes over the axle.... There isn't an S-pipe before the Cat. The Y-pipe comes from the Headers and goes to the Cat inlet. Why would you have an S-pipe before the Catalytic Converter?????<hr></blockquote>

Greg, you are partly right, nobody calls the pipe before the cat the S-pipe. However, the bends after the cat are called the s-pipe by many people. Secondly, if you re-read shortdog's post, you'll see what he meant by going into the cat... it means the pipe going into the cat from the direction of the muffler.

[black98V6]

<blockquote>quote:</font><hr>Originally posted by GregWS6'01:
S-pipe is what goes over the axle. If you ahve another set up then you don't technically have an S-pipe. You just have a fully welded I pipe that goes to your exhaust. There isn't an S-pipe before the Cat. The Y-pipe comes from the Headers and goes to the Cat inlet. Why would you have an S-pipe before the Catalytic Converter????? Can't think of reason why you'd need a pipe bending all over the place there when it'd be just a straight shot through the Y-pipe to the cat. The S pipe, is technically not an S. It's a hump to clear the area of the rear axle.<hr></blockquote>

naah man, I think you are misunderstanding, they are saying the S-pipe is after the cat, not before. The pipe they are reffering to comes out of the cat toward the rear of the car, makes a 90 degree bend to the driver side then goes about a foot and makes another 90 back to the rear of the car, from there it goes to the rear, over the axle and into the muffler. This S-pipe, (right after the cat) IS welded at least on newer cars but after the second 90 degree bend is a clamp you take off and that is where most aftermarket catbacks start. The reason they do this is so it is a "true" bolt on. to start the aftermarket system after the s-pipe, and not directly after the cat allows anyone with a little time and a few wrenches to install the system. to replace that S-pipe with a larger one requres cutting it at the cat and welding the new pipe on, it also requires you to have a new o2 sensor bungle welded into place right after the cat.

hopefully this clears everything up..

yeah what Haz-matt said too.. ;)

[ February 26, 2002: Message edited by: black98V6 ]</p>

[GregWS6'01]

Thank you Black98V6

[knowledgefreak]

<blockquote>quote:</font><hr>Originally posted by shortdog273:
I Agree with 96 T top. Some of the catbacks don't have the "S" shape going into the cat, but some fit directly on the cat. The "S" pipe is NOT the pipe that goes over the axle. For those who wanna get rid of that "S" pipe, order two 45 degree mandrel pipes from jcwhitney. It costs around 40 bucks. The size is up to you.<hr></blockquote>


uhh no dont do this you dont want an s shape at all that slows down the flow you want it as straight and less bends. No reason to have an s shape coming out of the cat at alll.

Everythign after the cat is the I pipe the s shape is part of the stock I pipe it is not a seperate pipe.

It is usually **** shops that cut your pipe at the end of the s bend and attach the cat back because it is easier to do that instead of welding new pipe to the stock cat.

[shortdog273]

[QUOTE]Originally posted by knowledgefreak:
[QB]


uhh no dont do this you dont want an s shape at all that slows down the flow you want it as straight and less bends. No reason to have an s shape coming out of the cat at alll.

Everythign after the cat is the I pipe the s shape is part of the stock I pipe it is not a seperate pipe.

Ok, but I know this already. I'm getting rid of the small pipe(S shape) the muffler shop left on and replacing it with a 3" custom made pipe.