X-Pipe
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X-Pipe
Does any one know who invented the X-Pipe? A couple of years ago I was reading a motor cycle magazine, and saw a short article. It showed a cafe style race bike built by Harley-Davidson in the 70's. The exhaust pipe was an X-Pipe. Has anyone else seen this bike?
crossover pipes
I can only offer my speculation from my little window on the world on this one. Exhaust crossover pipes first came to my attention in probably the 1980's I think.
About the time the Chrysler Street hemi came out (1966-67), people started discovering the advantages of large low back pressure exhaust systems. Thanks to the Chrysler Street Hemi muffler (PN 2781300 or the 1971 Imperial muffler PN 3466644 ) and the Corvair turbo mufflers, everyone and his dog was putting low back pressure dual exhaust systems up to 2 1/2" (large at the time) on big block V-8 engines. Many of these cars had formerly been piped with single exhausts.
In return for the effort they got a keen exhaust sound and noticably better performance and in many cases better gas milage, which became increasingly important after the 1973 oil shortages and skyrocketing gasoline prices in the late 1970's and early 1980's. The gas prices would even be high today at $3.00/gallon
In 1984, Chrysler put out a book on race setups for all the Chrysler line as part of their "Direct Connection" program, called "Mopar Chassis Carrol Shelby's Speed Secrets" They list every imaginable tweak and upgrade to improve your cars setup for racing/street performance including the above low back pressure Street Hemi and Chrysler Imperial mufflers, but no mention I could find on a crossover pipe.
David Vizard mentioned exhaust crossover pipes in his book "Performance with Economy" which first came out in 1981, and I'm sure there were tech articles on cross over pipes in the likes of Hotrod magazine in that period but I have no specific date/issues to point you to.
The crossover pipe probably dates to that period as a logical "lets see if this works" experiment by some never to be known hotrodder, trying to lower his exhaust back pressure by sharing the load between the dual exhaust muffler systems.
In the beginning these crossover pipes were what today are called "H" pipes, as they ran a short section of straight pipe betweent the dual pipes just behind the ends of the collectors if they were running headers. Depending on the lay out of the exhaust system, and the tranny/crossmembers the crossover generally was more or less under the drivers seat area.
It didn't take long for custom exhaust shops to start putting a knee bend in the dual exhaust systems near mid run to make the crossover pipe much shorter and bring it to the back of the transmission to get it away from the clutch and transmission.
This in my view was the beginning of the evolution toward the modern X-pipe sort of cross over.
I think the modern X-pipe system, if anyone can be attributed to be its inventor, it would be the folks at DR. Gas Exhaust components and the date would be near the early mid 1990's.
This article on their web site gives a little background on their work.
http://www.drgas.com/art-syncronicity.asp
Hope that helps answer your question? It would be interesting if someone on line here has one of the old Hotrod Magazine indexes and could scare up the first tech article on exhaust cross over pipes.
Larry
About the time the Chrysler Street hemi came out (1966-67), people started discovering the advantages of large low back pressure exhaust systems. Thanks to the Chrysler Street Hemi muffler (PN 2781300 or the 1971 Imperial muffler PN 3466644 ) and the Corvair turbo mufflers, everyone and his dog was putting low back pressure dual exhaust systems up to 2 1/2" (large at the time) on big block V-8 engines. Many of these cars had formerly been piped with single exhausts.
In return for the effort they got a keen exhaust sound and noticably better performance and in many cases better gas milage, which became increasingly important after the 1973 oil shortages and skyrocketing gasoline prices in the late 1970's and early 1980's. The gas prices would even be high today at $3.00/gallon
In 1984, Chrysler put out a book on race setups for all the Chrysler line as part of their "Direct Connection" program, called "Mopar Chassis Carrol Shelby's Speed Secrets" They list every imaginable tweak and upgrade to improve your cars setup for racing/street performance including the above low back pressure Street Hemi and Chrysler Imperial mufflers, but no mention I could find on a crossover pipe.
David Vizard mentioned exhaust crossover pipes in his book "Performance with Economy" which first came out in 1981, and I'm sure there were tech articles on cross over pipes in the likes of Hotrod magazine in that period but I have no specific date/issues to point you to.
The crossover pipe probably dates to that period as a logical "lets see if this works" experiment by some never to be known hotrodder, trying to lower his exhaust back pressure by sharing the load between the dual exhaust muffler systems.
In the beginning these crossover pipes were what today are called "H" pipes, as they ran a short section of straight pipe betweent the dual pipes just behind the ends of the collectors if they were running headers. Depending on the lay out of the exhaust system, and the tranny/crossmembers the crossover generally was more or less under the drivers seat area.
It didn't take long for custom exhaust shops to start putting a knee bend in the dual exhaust systems near mid run to make the crossover pipe much shorter and bring it to the back of the transmission to get it away from the clutch and transmission.
This in my view was the beginning of the evolution toward the modern X-pipe sort of cross over.
I think the modern X-pipe system, if anyone can be attributed to be its inventor, it would be the folks at DR. Gas Exhaust components and the date would be near the early mid 1990's.
This article on their web site gives a little background on their work.
http://www.drgas.com/art-syncronicity.asp
Hope that helps answer your question? It would be interesting if someone on line here has one of the old Hotrod Magazine indexes and could scare up the first tech article on exhaust cross over pipes.
Larry
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OldSStroker
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Thanks, Larry, for the interesting background. I recall similar OEM testing in the early-mid 60's with dual exhaust being used to improve fuel economy. Pontiac offered high compression, 2 bbl. engnes with dual exhaust for that reason. The dual option was about $30-$35 at the time. 2-1/4 inch headpipes and 2 inch tail pipes were the norm.
Jim Hall and his Chaparral cars used an H-pipe as far back as 1966 in their 2D coupe with the 327 SBC. The first appearance of the 2A in 1963 had 4 primary pipes ending in 4 inch or so collectors which were not even shaped to fit the tubes; they were just slipped over.
Soon they went to the eight individual "zoomies" pointing up thru the engine cover. They used these up thru about October 1965 at the LA Times GP. By Nassau Speed Week in December '65, they were using 4 into 1 with approx 3-1/2 in collectors routed thru the tail panel. As far as I can tell, they never went back to "zoomies".
By the 1966 2D, there was a long "H" crossover right at the 4>1 collector. Interestingly, the H seems to disappear when they converted to BBC in 1967, even though the collectors exited side by side in the center of the 2E, 2G and 2F. My guess is that the 327 benefitted from the mid-range torque improvement which might come from the H pipe, but the BBC had enough midrange to overpower the transmissions for quite a while before they were fixed. BTW, it wasn't an automatic trans. Just a manual box with a torque converter. The first one was only one speed, and when it won its first race, no one noticed it was an "automatic".
Chaparral's connection to GM is well known. I suspect the 4>1 with H-pipe may have come from Chevy Engineering Center. I do know that a few of CEC's sharpest engineers went to Chaparral.
So Hall & Co. were using them in '65 and the rest of us "discovered" them 15 or so years later. Where were we all that time? I'm still in awe of what Hall/GM accomplished in the late 60s.
Jim Hall and his Chaparral cars used an H-pipe as far back as 1966 in their 2D coupe with the 327 SBC. The first appearance of the 2A in 1963 had 4 primary pipes ending in 4 inch or so collectors which were not even shaped to fit the tubes; they were just slipped over.
Soon they went to the eight individual "zoomies" pointing up thru the engine cover. They used these up thru about October 1965 at the LA Times GP. By Nassau Speed Week in December '65, they were using 4 into 1 with approx 3-1/2 in collectors routed thru the tail panel. As far as I can tell, they never went back to "zoomies".
By the 1966 2D, there was a long "H" crossover right at the 4>1 collector. Interestingly, the H seems to disappear when they converted to BBC in 1967, even though the collectors exited side by side in the center of the 2E, 2G and 2F. My guess is that the 327 benefitted from the mid-range torque improvement which might come from the H pipe, but the BBC had enough midrange to overpower the transmissions for quite a while before they were fixed. BTW, it wasn't an automatic trans. Just a manual box with a torque converter. The first one was only one speed, and when it won its first race, no one noticed it was an "automatic".
Chaparral's connection to GM is well known. I suspect the 4>1 with H-pipe may have come from Chevy Engineering Center. I do know that a few of CEC's sharpest engineers went to Chaparral.
So Hall & Co. were using them in '65 and the rest of us "discovered" them 15 or so years later. Where were we all that time? I'm still in awe of what Hall/GM accomplished in the late 60s.
Jim Hall
Thanks !
Yes Jim Hall the Chapparal crew, and Carrol Shelby were my hero's in that time period. I built my first street racer in the 1965-67 period. It was a 54 Studebaker Champion with a full bore 392 Chrysler hemi backed up with a beefed Torqueflight. If I had known about cross over pipes they would have been on that car. So they were not on my radar at the time I got out of highschool.
Interestingly enough, I dug out a couple of my remaining Hot Rod magazines and found an advertizement for a full exhaust system with illustration of an "H" pipe cross over dual exhaust in the August 1964 edition. It is listed as:
"DS-44 Douglass-Mustang equalized dual exhaust sytem with matched mufflers and chrome slash-cut tailpipes"
In the July 1964 edition I find another Douglass Muffler advertisement that has no mention of the "equalized" exhaust system or a picture of the "H" pipe exhaust.
It would appear that the "H" style crossover equalization appeared on the general market around summer 1964 time period. This meshes nicely with your comments about the Chaparral.
Larry
Yes Jim Hall the Chapparal crew, and Carrol Shelby were my hero's in that time period. I built my first street racer in the 1965-67 period. It was a 54 Studebaker Champion with a full bore 392 Chrysler hemi backed up with a beefed Torqueflight. If I had known about cross over pipes they would have been on that car. So they were not on my radar at the time I got out of highschool.
Interestingly enough, I dug out a couple of my remaining Hot Rod magazines and found an advertizement for a full exhaust system with illustration of an "H" pipe cross over dual exhaust in the August 1964 edition. It is listed as:
"DS-44 Douglass-Mustang equalized dual exhaust sytem with matched mufflers and chrome slash-cut tailpipes"
In the July 1964 edition I find another Douglass Muffler advertisement that has no mention of the "equalized" exhaust system or a picture of the "H" pipe exhaust.
It would appear that the "H" style crossover equalization appeared on the general market around summer 1964 time period. This meshes nicely with your comments about the Chaparral.
Larry