exhaust Question
Thread Starter
Instructor
Joined: Feb 2005
Posts: 140
Likes: 0
From: cookeville tn
exhaust Question
My exhaust is started to rust. I want to build my own out of stainless. I want to start from just behind the the 2 small converters and run 2 pipe's side by side under the drive shaft then spit to the mufflers. I want to do away with the main converter. I work at a fab. shop and get the tube at cost. I have the pipe bender and everything I need. My question is. Will it help or hurt my car. My first thought is it, it should help it breath. But does it need the back pressure. Any thought's. thanks
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Usually people remove the pre-cats (or gut them) and leave the main cat in place. If you are required to do emissions testing, the loss of the main cat will probably cause the car to fail.
You could replace the pre-cats with some high-flow cats that should keep the emissions down. Just make sure the o2 sensors are in the same relative position downstream as the OEM location.
You should consider adding an X-pipe in the middle as that will cut some of the resonance and improve the exhaust flow. If the engine is stock, stay with 2 1/2 to 2 3/4 inch pipe all the way back.
Muffler choice is up to you but without the cats expect an pretty good increase in sound level
You could replace the pre-cats with some high-flow cats that should keep the emissions down. Just make sure the o2 sensors are in the same relative position downstream as the OEM location.
You should consider adding an X-pipe in the middle as that will cut some of the resonance and improve the exhaust flow. If the engine is stock, stay with 2 1/2 to 2 3/4 inch pipe all the way back.
Muffler choice is up to you but without the cats expect an pretty good increase in sound level
Thread Starter
Instructor
Joined: Feb 2005
Posts: 140
Likes: 0
From: cookeville tn
Thanks for the quick reply. I have the 2 1/2 pipe already and was trying to save on the main cat. I live in tn and we don't have inspection or a noise level restriction. The car is bone stock. I have some work ahead of me. It drives and runs very good. This is my first vette and think I got a good deal for it. I paid $3700 for it. Its a 1990 w/ 130,000 on it. It's the car in my avatar. One more question. Why use a x-pipe. Does a x-pipe add back pressure, where the straight pipe lets the exhaust flow straight out. thanks
