Mako
Well-known member
I have a rather unusual side pipe setup on my '69 that you might be interested in knowing about.
The problem with a conventional sidepipe setup is that it is not a tuned length pipe and the compromise between too loud for better power and quiet but choking the engine is an unpleasant one to have to make. I wanted it all: reasonably quiet but with unrestricted power.
Thinking the problem through led me to decide that what was really needed was a removable side pipe setup that would allow me to swap between a set of ear ball saving street pipes and a set of tuned length WFO race pipes.
I discussed this idea with Dave Herlinger at Corvette Repair in Mountain View, CA. I have 3" collectors on my Stahl headers. But a 3" pipe with a muffler insert really sucks too much power. I found that Pertronix (of ignition fame) makes a 3.5" insert for street rodders - perfect! So the street pipes are 3.5" in diameter in an attempt at keeping exhaust flow up some and the WFO race pipes are the correct 3" and cut to length per Jere Stahl's advice.
Once we had a good idea of how it was all going to work, Dave fired up his TIG and fabricated a set of test sidepipes for me.
I took the car to Sacremento and the pipes worked well, but due to frame flex on the launch, the welds on the tabs that bolted the tubes onto the frame failed.
We addressed that by using wider strap steel and installing bushings in the tabs that allow the frame to flex without over stressing the welds on the pipes.
That proved to work splendidly. Dave then fabricated the "for real" pipes. A full length set with muffler insterts for the street and a tuned length of WFO pipes for the strip.
I'm exceptionally pleased with the way things have worked out. I can swap between the eye candy and acceptably quiet street pipes and the WFO pipes in about 15 minutes in the pits.
I have setup a web page with pics and a parts and vendor list on my web page (click the photo of my car below) under the Sidepipe Fabrication link if you are interested in learning more.
CYa!
Mako
The problem with a conventional sidepipe setup is that it is not a tuned length pipe and the compromise between too loud for better power and quiet but choking the engine is an unpleasant one to have to make. I wanted it all: reasonably quiet but with unrestricted power.
Thinking the problem through led me to decide that what was really needed was a removable side pipe setup that would allow me to swap between a set of ear ball saving street pipes and a set of tuned length WFO race pipes.
I discussed this idea with Dave Herlinger at Corvette Repair in Mountain View, CA. I have 3" collectors on my Stahl headers. But a 3" pipe with a muffler insert really sucks too much power. I found that Pertronix (of ignition fame) makes a 3.5" insert for street rodders - perfect! So the street pipes are 3.5" in diameter in an attempt at keeping exhaust flow up some and the WFO race pipes are the correct 3" and cut to length per Jere Stahl's advice.
Once we had a good idea of how it was all going to work, Dave fired up his TIG and fabricated a set of test sidepipes for me.
I took the car to Sacremento and the pipes worked well, but due to frame flex on the launch, the welds on the tabs that bolted the tubes onto the frame failed.
We addressed that by using wider strap steel and installing bushings in the tabs that allow the frame to flex without over stressing the welds on the pipes.
That proved to work splendidly. Dave then fabricated the "for real" pipes. A full length set with muffler insterts for the street and a tuned length of WFO pipes for the strip.
I'm exceptionally pleased with the way things have worked out. I can swap between the eye candy and acceptably quiet street pipes and the WFO pipes in about 15 minutes in the pits.
I have setup a web page with pics and a parts and vendor list on my web page (click the photo of my car below) under the Sidepipe Fabrication link if you are interested in learning more.
CYa!
Mako
Never got pulled over for noise though whew!
