H pipe performance
Burning Brakes
Joined: Jul 2000
Posts: 1,162
Likes: 2
From: Beaverton, OR
big_G, I'm sure that is because they forgot to install the sticker that came with the pipe. 
Hmm, now I wonder if it's worth it to put one in when I redo my exhaust setup. . . Awww, can't hurt, though I think I'll go the X pipe route if I can fit it under there, but the idea's the same.
-dath
Hmm, now I wonder if it's worth it to put one in when I redo my exhaust setup. . . Awww, can't hurt, though I think I'll go the X pipe route if I can fit it under there, but the idea's the same.
-dath
Le Mans Master
Joined: Mar 2004
Posts: 7,470
Likes: 1,492
From: Little Rock AR
The H-Pipe will smooth out the pulses (sound) and increase power below the torque peak. Technicaly, this is not a power increase if you see what I am saying.
Peak HP should stay about the same as was reported but lower RPM performance below the peak is improved. This is what gets lost in the details.
-Mark.
Peak HP should stay about the same as was reported but lower RPM performance below the peak is improved. This is what gets lost in the details.
-Mark.
Racer
Joined: Mar 2005
Posts: 343
Likes: 0
From: San Diego CA
St. Jude Donor '05-'07
Originally Posted by dath
I think I'll go the X pipe route if I can fit it under there, but the idea's the same.
-dath
-dath
I put one in when I redid my exhaust...honestly I don't know how much improvement it gives, I'd guess less than 10 HP, but if you are doing a complete system anyway you may as well get stupid with it!! Go as far as you can.
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
Seems to me that the H pipe equalizes pressure side to side while the X pipe increases the cross section of the exhaust behind the X thus reducing backpressure and improving scavenging.
The X will lower the sound level and raise the sound an octave. Very nice, IMHO....
The X will lower the sound level and raise the sound an octave. Very nice, IMHO....
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Thread Starter
Safety Car
Joined: May 2005
Posts: 4,176
Likes: 7
From: Jennings LA
looks like I should do it
on my 81 both pipes go down the passenger side, so the drivers side pipe has a huge bend in it where it goes around the back of the trans to the passenger side, the passenger side is a straight shot all the way to the rear axle so I am sure they are way out of balance. my pipes are only about 3 inches apart do you think I could get this one to fit?
http://store.summitracing.com/defaul...=egnsearch.asp
are there any others?
http://store.summitracing.com/defaul...=egnsearch.asp
are there any others?
Safety Car
Joined: Jul 2002
Posts: 3,770
Likes: 3
From: St Louis MO
This is what I put on mine:
http://store.summitracing.com/defaul...=egnsearch.asp
<---Video in my briefcase if You want to hear what it sounds like....exhaust is: headers, 2.5" duals, x-pipe under differential, 2 dynomax ultra-flo (# 17219).
Brett
http://store.summitracing.com/defaul...=egnsearch.asp
<---Video in my briefcase if You want to hear what it sounds like....exhaust is: headers, 2.5" duals, x-pipe under differential, 2 dynomax ultra-flo (# 17219).
Brett
Melting Slicks
Joined: Dec 1999
Posts: 2,116
Likes: 156
From: Mid West
Cruise-In III Veteran
Originally Posted by flynhi
Seems to me that the H pipe equalizes pressure side to side while the X pipe increases the cross section of the exhaust behind the X thus reducing backpressure and improving scavenging.
The X will lower the sound level and raise the sound an octave. Very nice, IMHO....
The X will lower the sound level and raise the sound an octave. Very nice, IMHO....
The X pipe I installed definitely raised the sound an octave and removed the resonance. Don't know about any HP gain.
Safety Car
Joined: Jul 2002
Posts: 3,770
Likes: 3
From: St Louis MO
Originally Posted by gator79
Brettmc
sure lets here it, looks like you have big block, mine is a 383, where did you mount your X pipe?
sure lets here it, looks like you have big block, mine is a 383, where did you mount your X pipe?
I goofed. I said the link to my briefcase was to the left but it's really in my sig.
Brett
Racer
Joined: Feb 2005
Posts: 258
Likes: 2
From: Boise ID
I'm planning on doing this too...
I read somewhere that an H - pipe should be a smaller diameter than the exhaust pipe. Can anyone else verify this?? I think I saw it on the corvettefaq H-pipe topic.
Thanks!
Dan
Thanks!
Dan
Drifting
Joined: Jun 2005
Posts: 1,950
Likes: 498
From: Chino Hills CA
When I installed the H pipe on my '72, I expected a big improvement in sound quality of the exhaust, I was a little dissapointed. When I put an H pipe on my '55 shoebox, it made a big difference. I think when the mufflers are closer to the engine, the exhaust has more time to resonate in the pipes before it reaches the tips. On the C3, since the mufflers are at the tips, it makes it sound a littler ratty. The H pipe did smooth out out the sound and did reduce the popping, but not as much as I expected, no performance increase I could feel, (small block, headers, 2 1/2" and flowmasters). I did install a flange in ther middle of the H pipe to make it easy if I ever had to remove the exhaust system in the future.
Safety Car
Joined: Dec 2004
Posts: 4,876
Likes: 1
From: Jersey Shore Exit 98
Before you spend the $$ and do the work. Try this. I was thinking about doing the same thing to my 79 w/dual 2.5 exhaust w/headers & flowmaster mufflers.
My buddy Bobs77vette asked me why was I thinking about changing my setup I said because its an upgrade. Bob who knows more then the average bear said your not going to pickup that much HP's to justifiy the $$. Then he said do you ready what to change the sound?
I just looked at him & he said give me the keys & stand at the end of my driveway. I did & he took 3 passes & man that vette sounds good.
That's what Bob said & I didn't put in the H or X pipe.
Try this before you spent any $$..
My buddy Bobs77vette asked me why was I thinking about changing my setup I said because its an upgrade. Bob who knows more then the average bear said your not going to pickup that much HP's to justifiy the $$. Then he said do you ready what to change the sound?
I just looked at him & he said give me the keys & stand at the end of my driveway. I did & he took 3 passes & man that vette sounds good.
That's what Bob said & I didn't put in the H or X pipe.
Try this before you spent any $$..
Team Owner
Joined: Apr 2002
Posts: 62,198
Likes: 1
From: All humans are vermin in the eyes of Guru VA
Cruise-In IV Veteran
Cruise-In V Veteran
Lingenfelter in his book said make them as big as you can, and its good for some torque down low. Just read it last night.
Sounds like it evens out the exhaust more than anything else.
Sounds like it evens out the exhaust more than anything else.