H-Pipe, X-Pipe specification questions?
Thread Starter
Le Mans Master
Joined: Aug 2000
Posts: 9,662
Likes: 7
From: Semper ubi, sub ubi
Cruise-In VI Veteran
Cruise-In VII Veteran
H-Pipe, X-Pipe specification questions?
I've got a buddy with a 79 and true duals. He is installing headers and a new exhaust to his system and wants to put in a H-Pipe or X-Pipe. We have both heard that to get maximum benefit the crossover pipe needs to be a certain distance back from the header collectors. Is there a formula that determines the best place to put the crossover?
It looks like the only place that truly has the room is behind the crossmember. Where have you guys with them put yours?
Thanks
It looks like the only place that truly has the room is behind the crossmember. Where have you guys with them put yours?
Thanks
Drifting
Joined: Mar 2001
Posts: 1,411
Likes: 2
From: St. Louis, Missouri
Re: H-Pipe, X-Pipe specification questions? (Smokehouse69)
Here's what I read about H pipes when they started becoming the shizit about 17 years ago. The location wasn't super critical but the pipe diameter should be roughly 75% of your main pipe diameter. Some of the better setups I 've seen have a bolt-in crossover pipe so the tranny can be removed without disconnecting the exhaust.
Don't know about X-pipes.
Don't know about X-pipes.
Instructor
Joined: Feb 2002
Posts: 126
Likes: 0
From: Altus OK
Re: H-Pipe, X-Pipe specification questions? (Smokehouse69)
I talked to my muffler guy about this. He said that he uses the crayon trick. Stripe your exhaust with a fat crayon, put the crossover in where the crayon stops burning. Don't use black or you won't be able to see the burn.
Safety Car
Joined: Jul 2001
Posts: 3,921
Likes: 2
From: York PA
Re: H-Pipe, X-Pipe specification questions? (Smokehouse69)
If I remember correctly. For maximum power you want to put the crossover at the hottest point. You can find this by put a line on with a crayon and see where the first place it burn off. If you are just putting the crossover to get rid of some unwanted resonance (sp?) you can put it anywhere before the mufflers. Most people I have heard that put them on c3's put them behind the crossmember because it would drag everywhere if you put it under the tranny :cheers:
Instructor
Joined: Mar 2001
Posts: 192
Likes: 0
Re: H-Pipe, X-Pipe specification questions? (Smokehouse69)
Smokehouse69.
C2 and C3 corvettes are pretty limited as to where the X-pipe can go. I had mine put as close to the crossmember as possible. Ideally it would go where the crossmember is located.
Go with the X-pipe, not the H-pipe. I started out with an H-pipe and switched to an X-pipe. It made a big difference in sound and power. It quieted down my 406 quite a bit and it went from running rich to running just about right. If you look at all of the dyno tests that have been printed, X-pipes get about the same Hp as open headers. They almost always beat H-pipes by around 20 HP on a performance motor.
Mike
C2 and C3 corvettes are pretty limited as to where the X-pipe can go. I had mine put as close to the crossmember as possible. Ideally it would go where the crossmember is located.
Go with the X-pipe, not the H-pipe. I started out with an H-pipe and switched to an X-pipe. It made a big difference in sound and power. It quieted down my 406 quite a bit and it went from running rich to running just about right. If you look at all of the dyno tests that have been printed, X-pipes get about the same Hp as open headers. They almost always beat H-pipes by around 20 HP on a performance motor.
Mike
Drifting
Joined: Jun 2000
Posts: 1,752
Likes: 1
Re: H-Pipe, X-Pipe specification questions? (Fevre)
check out 71roadster's here: http://temp.corvetteforum.net/c3/71roadster/
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Tech Contributor
Joined: Aug 1999
Posts: 15,160
Likes: 3,965
From: Connecticut, USA
Re: H-Pipe, X-Pipe specification questions? (Smokehouse69)
I had the shop install an H pipe with a V bent in it to fit in front of the tranny and behind the bellhousing. They used a 2" pipe the mains are 2.5" chambered. The only problem was I had to cut them square and remove the pipe from the crossmember back when I started rebuilding the rear suspension.
Gary
Gary
