Exhaust Pipe Diameter ?
Thread Starter
Melting Slicks
Joined: Mar 2004
Posts: 3,472
Likes: 18
From: Lake Ozark, MO
Exhaust Pipe Diameter ?
Right now my new 454 is running headers thru 2 1/2 inch piping (no cats) to 40 series Flowmasters. My engine is expected to put out around 500HP. Cam makes power from 2500 - 6000.
Is the existing 2 1/2 pipe too small or should I go to 3 inch pipe? I'm considering changing the system because all the pipes have been kinked where they were bent (not mandrel?) and flattened in places by the mom and pop muffler shop to make them fit.
Is the existing 2 1/2 pipe too small or should I go to 3 inch pipe? I'm considering changing the system because all the pipes have been kinked where they were bent (not mandrel?) and flattened in places by the mom and pop muffler shop to make them fit.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I believe in free flowing exhaust. Because drag engines that have only headers with correct length colletor extensions make more power than any full length exhaust system.
I have had 3 inch duals with 3 inch in out mufflers since the 80's
I have had 3 inch duals with 3 inch in out mufflers since the 80's
Thread Starter
Melting Slicks
Joined: Mar 2004
Posts: 3,472
Likes: 18
From: Lake Ozark, MO
Motorhead...good picture. I'll take it to the shop so they can see how It should be done.
I have a 3 inch X pipe I bought off Ebay some time ago. Is that worth installing? Guess it would have to be fitted right behind the cross member?
I have a 3 inch X pipe I bought off Ebay some time ago. Is that worth installing? Guess it would have to be fitted right behind the cross member?
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Motor head you have a nice system! 
I went for the straight back pipes to give me additional speed! I've also found that looks must be intimidating because nobody ever comes up and wants to race me. The chrome tips are 3 1/2 by 12 inches
I went for the straight back pipes to give me additional speed! I've also found that looks must be intimidating because nobody ever comes up and wants to race me. The chrome tips are 3 1/2 by 12 inches
Race Director
Joined: Apr 2000
Posts: 17,676
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
I think it looks a little lower than it really is. There is about 4 inches of clearance there but my rear wheel well lip is at about 29 in. I have never had any problems with it. So if car is lower then you might want to check the clearance with 3 in. pipes 
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Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Motor head how loud is your system? Or do you have a video with sound? I have a 3 inch dia. cross over under the differential. I also had the "no pride" in his work guy at Mienike Mufflers install the custom system. When I came to get my car the output pipe tips were not spaced equal in either the horizontal or verticle directions. I had to get the manager involved in getting them straight and the one lower pipe still came out wrong.
Team Owner
Joined: Apr 1999
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Motorhead do you have a video of how your car sounds?
I also have a 3 inch cross over under the differential. I had my custom pipes put on at Mieneke Mufflers by a guy that didn't take any pride in his work. When I came to get my car the tail pipe tips were off both horizontaly and verticaly. so I had to get the manager involved and they are still uneven underneath
I also have a 3 inch cross over under the differential. I had my custom pipes put on at Mieneke Mufflers by a guy that didn't take any pride in his work. When I came to get my car the tail pipe tips were off both horizontaly and verticaly. so I had to get the manager involved and they are still uneven underneath
Race Director
Joined: Apr 2000
Posts: 17,676
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
George, i only have a video of the Flowmaster 40's on the car. They sounded too tinny, and had a real bad interior resonance. I took them off after 1 week, I put on Super Turbos and don't have a clip, I am going change back to MagnaFlows in the spring The clip is pretty lame but it gives you an idea of why I took them off. Others seemed to like them but if gets embarrassing when cars stop 20 feet behind you at a stop light because the don't want to get too close to the noise
http://media.putfile.com/s-Vette-full-throttle-2
http://media.putfile.com/s-Vette-full-throttle-2
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Flowmasters - That is a dead ringer for my buddys 427 BBC 67 Camero. He thinks it's got the the race car sound. At certian throttle positions and rpm it vibrates the whole car. It's way annoying to drive around in
