H pipe results
Thread Starter
Drifting
Joined: Jan 2002
Posts: 1,606
Likes: 1
From: Las Cruces NM
H pipe results
I had to get a few welds re-done that were a little shoddy on the exhaust and while I had it in, I talked to the owner of the shop (with a really nice 78, mildly built motor) about X and H pipes. He mentioned that an X pipe looks cool but on lower hp vehicles isn't really helpful. It's more for very high RPM, high hp motors.
Anyhow, mine's a small block, probably around 350-375hp or so....041 heads and a pretty healthy cam. The exhaust looks like one of those systems you'd get out of mid america or something.
I got the H pipe in and the sound is way, way quieter. I almost can't believe 8 inches of pipe could do that. It does sound less like a big cam race car and more toned down like a muscle car should. Much less rowdy, which I'm ok with. But it's a little too quiet for me.
What i really noticed, though, is the low end torque. Before, with the cam I had, it really didn't come alive till after 2000rpm. Now, it spins up quicker and gets into its power band faster. It jumps off the line. Of course, this is all butt-o-meter, so it may not have made much difference on paper. I'm really happy with it for anyone that was contemplating it.
C
Anyhow, mine's a small block, probably around 350-375hp or so....041 heads and a pretty healthy cam. The exhaust looks like one of those systems you'd get out of mid america or something.
I got the H pipe in and the sound is way, way quieter. I almost can't believe 8 inches of pipe could do that. It does sound less like a big cam race car and more toned down like a muscle car should. Much less rowdy, which I'm ok with. But it's a little too quiet for me.
What i really noticed, though, is the low end torque. Before, with the cam I had, it really didn't come alive till after 2000rpm. Now, it spins up quicker and gets into its power band faster. It jumps off the line. Of course, this is all butt-o-meter, so it may not have made much difference on paper. I'm really happy with it for anyone that was contemplating it.
C
Racer
Joined: Sep 2005
Posts: 453
Likes: 1
From: Austin TX
Do you have to buy the H pipe from somewhere or can the shops usually just make it out of regular pipe? I'm still waiting to put exhaust on my 78 406ci. I ordered the super 40s from jegs wednesday and hope to be in the exhaust shop next week/weekend.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
The shops can make one up very easily. I had mine made up wit ha ball and socket joint. This made for easy removal of the exhaust system. I'm glad I did it 6 years ago because I have had mine off every winter since for upgrades. I can have my exhaust off in a matter of 1/2 hour.
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
The shops can make one up very easily. I had mine made up wit ha ball and socket joint. This made for easy removal of the exhaust system. I'm glad I did it 6 years ago because I have had mine off every winter since for upgrades. I can have my exhaust off in a matter of 1/2 hour.
gordon do you have picture of this? thks bob
Drifting
Joined: Sep 2006
Posts: 1,986
Likes: 21
From: Columbus MN
HOWEVER, a premade balance pipe might look nicer where the cross pipe joins the exhaust pipes. Like these:
http://store.summitracing.com/partde...5&autoview=sku
http://store.summitracing.com/partde...5&autoview=sku
I don't know for sure though because I've never seen one of these. You can also buy just the cross pipe ends, but the exhaust guy still needs to cut the main pipes.:
http://store.summitracing.com/partde...5&autoview=sku
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Drifting
Joined: May 2005
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From: Somers CT
Bill
Safety Car
Joined: Oct 2005
Posts: 3,570
Likes: 1
From: Algonac Michigan
By the way...I heard this from an old tuner. He said when you install a crossover pipe, you need to know where to put it. He suggested that with the old exhaust still intact and the exhaust cold, get under the car and with a wax crayon mark the pipe from collector to axle. Then start the car and watch where the crayon starts to melt first. That is where you want to put the crossover pipe! Something to do with resonance.
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
By the way...I heard this from an old tuner. He said when you install a crossover pipe, you need to know where to put it. He suggested that with the old exhaust still intact and the exhaust cold, get under the car and with a wax crayon mark the pipe from collector to axle. Then start the car and watch where the crayon starts to melt first. That is where you want to put the crossover pipe! Something to do with resonance.
Thread Starter
Drifting
Joined: Jan 2002
Posts: 1,606
Likes: 1
From: Las Cruces NM
The exhaust shop I went to is no stranger to Corvettes...like the owner's 78. He said ideally you'd want it where you said, about a foot and a half behind the collectors. Mine is about 6 inches behind the crossmember, right below the front of the driveshaft.
The shop mandrel bent the tube so it has a very shallow U shape. He said they do that to give more room around the driveshaft if I have to remove it. The try to do that and still not sacrifice ground clearance. It hangs about the same as the header collectors do.
They did a really superb job on it, with the ends cut to fit around the pipe. Even before he welded, there was no gap between the primary pipes and the crossover.
What's nice, is that there was a very noticeable improvement all the way around for only about $50. The whole trip cost me $100, including the H pipe, 3 or 4 welds, some other small weld touch ups and a couple new clamps.
C
The shop mandrel bent the tube so it has a very shallow U shape. He said they do that to give more room around the driveshaft if I have to remove it. The try to do that and still not sacrifice ground clearance. It hangs about the same as the header collectors do.
They did a really superb job on it, with the ends cut to fit around the pipe. Even before he welded, there was no gap between the primary pipes and the crossover.
What's nice, is that there was a very noticeable improvement all the way around for only about $50. The whole trip cost me $100, including the H pipe, 3 or 4 welds, some other small weld touch ups and a couple new clamps.
C
Melting Slicks
Joined: Apr 2004
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From: Space Coast Gator Territory
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Racer
Joined: Sep 2005
Posts: 453
Likes: 1
From: Austin TX
Cool. I just had the exhaust done today on my 78. I had 2.5" duals, H-pipe and Super 40s installed. Exhaust guy made the h pipe out of regular tube. Overall he did a nice job on it, I think.
Sounds pretty deep and mean. Definately quieter in the cab than the old Delta 40s on my 355ci truck. I'll try to take some pics or videos tomorrow with sound. I know alot of people ask questions about these muffers and how loud they are. Now I need to replace my throttle cable so the secondaries open all the way on the demon.
Sounds pretty deep and mean. Definately quieter in the cab than the old Delta 40s on my 355ci truck. I'll try to take some pics or videos tomorrow with sound. I know alot of people ask questions about these muffers and how loud they are. Now I need to replace my throttle cable so the secondaries open all the way on the demon.