exhaust help

[ls67]

I posted this in the exhaust section but I guess it is pretty slow over there. So anybody????

I am going to order my exhaust and want opinions on sound and performance on 2.5 or 3 inch exhaust. What would be better on a stock ls1 with mac headers in a 67 camaro. I am looking at flowmaster 40s

thanks

[CHILI442]

I can't see why you would need 3" with a stock LS1

[ls67]

yea thats what I suspected and I even suspect that the ls1 may even be better off with the 2.5 but I dont have any data to back that up but would it sound significantly better with 3 inch?

[rockdogz]

yea thats what I suspected and I even suspect that the ls1 may even be better off with the 2.5 but I dont have any data to back that up but would it sound significantly better with 3 inch?

I think you're going at it from the wrong angle - go with the 2.5 and if you want a different sound change out the muffler.

[CHILI442]

3" pipe will make it sound like 3" pipe.

There's so many variables when it comes to exhaust sound.

Mandrel bent pipe will make it sound louder than crush bent (muffler shop) pipe too.

[rocketman]

I would go head and do a 3inch system,If it needs backpressure change the muffler out.

[FabUThis]

LS1 works very well with a 3'' exhaust and X pipe

[CAMAROBOY69]

If you want it louder go 3" If you want it quiter go 2 1/2" It will have a different tone with 3"

[69ratfed]

Go with a 3'' Dr.Gas x-pipe, 3'' Spintech Sportsman XL and 3'' Torque Tech tail pipes. AWESOME sound at idle and at wot, you just would not believe the sound. Nothing like I have ever heard. I am really satisfied with my choices.

[GIDRDUN]

2 1/2" is good to about 450 hp. 3" is good to about 550 hp. Both in a dual configuration. X-Pipe if you have the room. They work in a wider RPM range than a standard H-Pipe. Hope this helps.

[wickedridz]

for a "stock" LS1 a prefab flowmaster kit will work just fine. the american thunder series from personal experiance on a car i built sounds awsome and except for the header flange fab is a bolt in deal in your driveway.

[Kennymax]

I bought my 67 camaro with a 327 that has a very large cam. My "very young" cousin put a 3" pipe with racing flowmaster mufflers cut at the muffler down ward under the seats. My result was a very loud drone in the car obnoxious to myself and others. I know that loud is the way to go but this was annoying. So went to the muffler shop where the guy is a master at classic cars he went down to a 2.5 inch pipe and some mufflers." Forgot the kind" now it sounds like a POS. I can't stand it. So my question is? Do I keep the 2.5 inch and change my mufflers? If so what's the best to be heard before your seen in a cool classic sound "cam American muscle popping crisp and deep"? Or should I have just kept the 3" and changed the mufflers and ran them out the back? Thanks I'm new to all this