Exhaust question
Thread Starter
Le Mans Master
Joined: Jan 2001
Posts: 6,938
Likes: 1
From: San Diego CA
Exhaust question
Monday I'm dropping the 68 off at http://www.edhansonsmuffler.com/ and he's going to put on 3" aluminized pipe with cross-over and flowmasters. Ed plans to leave breaks to allow me to remove the exhaust for maintenance such as removing the tranny, rear end etc. which I coudn't do before due to the fact my current exhaust is one piece from the collectors on back. Given the limited room betwen the header flange and the frame cutouts we have agred to have the breaks after the frame cutouts and H-pipe. This should allow me to disconnect the band clamps and pull the entire rear section in the case of a blown rear end or in the case of a tranny rebuild I can disconnect the breaks and push the forward section back till the pipe to header flanges hit up against the frame cutouts which leaves plenty of room to get in there and work the tranny. Sorry no pictures, it would make my explanation much easier. If you have any pictures of this setup I'm decribing or have better ideas please feel free to post the here.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
3" is way more than that 327 will ever need. A 2 1/2 will feed up to about 500HP. The 2 1/2 will fit much better. I have a system similar to what you are talking about. Mine comes apart very easily. I can take off the whole back half as one unit or split it at the H pipe. My H pipe has a ball and socket that comes apart very easily. Here it is with it unclamped but not apart. You can see the band clamps also. 
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Originally Posted by 7t2vette
Never seen those band clamps before, just the 4" wide ones. Where did you get them? Do they seal okay?
SuperTrapp T-Bolt Exhaust Clamps
Exhaust Clamp, T-bolt, Stainless Steel, 2.5 in. Diameter, Each
You can get them in diff sizes for diff diam pipes.
Instructor
Joined: May 2004
Posts: 167
Likes: 0
From: Pompano Bch Florida
I just had 3" exhaust put about a month ago. I had to notch my trany cross member so the pipe came staight off my headers and tuck up under the car. I had header flanges put on after the x-pipe just under the the rear so I can take down the trany or the rear with out removing the hole thing. I'll send pics later today. My camera is at my shop. The guy did a fantastic job. All mandrel bent. I had a set of 2 chamber flow masters so we put those on. It sounds like a big block. I can also take off the flow masters at the flange and run open headers thru the x-pipe.
I have to agree that a 3" pipe is a little over kill for a 327 unless it's all worked up. Now if your not going with mandrel bent, then the 3" will be ok depending on how many bends there are . Good luck and I'll post pic later of my exhaust. Vince
I have to agree that a 3" pipe is a little over kill for a 327 unless it's all worked up. Now if your not going with mandrel bent, then the 3" will be ok depending on how many bends there are . Good luck and I'll post pic later of my exhaust. Vince
Melting Slicks
Joined: Dec 1999
Posts: 2,116
Likes: 156
From: Mid West
Cruise-In III Veteran
3" is probably too big, but that's what I just put on my 350 ZZ4 that's been worked over some. Have to see how it runs later this spring. 3" can be made to fit thru the factory crossmember if your REALLY careful. Here's some pics of my install with an X-pipe and Borla mufflers. The exhaust goes to 2 1/2" after the X-pipe to fit the mufflers .... so its kinda a 3" but kinda a 2 1/2" also.
Last edited by Jason Staley; Feb 26, 2005 at 04:25 PM.
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Thread Starter
Le Mans Master
Joined: Jan 2001
Posts: 6,938
Likes: 1
From: San Diego CA
Originally Posted by Gordonm
Here is another shot of the exhaust. I have the band clamps and also the 4 inch wide clamps. They are the ones you can see slightly hanging down in this picture.
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Last edited by Cali,68,L-79; Feb 26, 2005 at 09:52 PM.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
I really did not need the H pipe to split but when it is together it is heavy and kind of tough to handle with one person. I have taken it off both ways and it is easier to split it.
Race Director
Joined: Feb 2005
Posts: 16,100
Likes: 17
Bigger isn’t always better. Systems that are too large in diameter can actually hurt performance. Improved flow is what you need.
Ed did my exhaust three weeks ago.But my 78 L-82 has to smog.So I got 2 1/4" thru a 3" Cat,then 2 1/2" split out thru two Dynamax mufflers.Got increased flow and power.
Ed did my exhaust three weeks ago.But my 78 L-82 has to smog.So I got 2 1/4" thru a 3" Cat,then 2 1/2" split out thru two Dynamax mufflers.Got increased flow and power.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Not enough back-pressure is nonsense!
Headers and exh pipes will always provide enough back pressure. 
Why do they run open headers at the strip? Too much torque? 
I doubt it. U will always have too much back pressure with pipes behind the headers. But 3" pipe is a problem to install all the way back and get it right.
Only need some pipe at exh port to prevent vlv from burning - no i can't explain that but that's what i read why dragsters need them. cardo0
Why do they run open headers at the strip? Too much torque? I doubt it. U will always have too much back pressure with pipes behind the headers. But 3" pipe is a problem to install all the way back and get it right.Only need some pipe at exh port to prevent vlv from burning - no i can't explain that but that's what i read why dragsters need them. cardo0
