Anyone heard of this? The idea is to find what RPM your car drones. Then after some simple multiplication and division, you can find the length of tube required to add to your exhaust to kill drone at that RPM.
It's been around for a long time being used in intake tract silencers. There is a 13pg thread on a mustang forum where people have done this and came out with amazing results. This goes deeper than the mustang crowd too. Since researching, I have found it on Beemr forums,Audi forums and other "sensitive hearing" oriented car enthusiaites.
Quote from post in Mustang forum from the guy who started it:
"My magnaflow had the usual 2000 rpm drone, so I tried something a little different (I think) to get rid of it. The drone is now not just better, it is completely gone - the exhaust is downright quiet cruising at 2000 rpm. I read an article on the internet about "tailpipe resonance", and decided that this has to be the problem with aftermarket catbacks. They probably all have the same 6ft tailpipe mine has, which if the exhaust is at about 500 degrees, will resonate at 134 Hertz, which is the engine firing rate at 2000RPM. So I added a 134 Hz, 1/4 wave resonator to both tailpipes. Its just a section of pipe "T"ed into the tailpipes right in front of the gas tank. They are about 26" long each, which maybe a little shorter than ideal, but that's what fits in the available space. 26" must be long enough, because it sure as heck works. One end of each pipe is welded shut, and the other is T'ed into the tailpipes. If anyone is interested, I can try and post a picture."
Corsa of course promotes a RSC Technology in their mufflers which goes beyond this since they are able to tune the drone withing the confines of a muffler.
You would simply "T" off your exhaust with a centerline length of tube that you calculated and cap the end....done. My drone comes in at 1700 and stops around 2000, so I calculated based on 1750rpm giving me 29" of pipe needed.
How I plan to redo mine...mimic the Corsa single 3" but with a pipe "t'd" off. (not to scale)
On a Mustang:
On a GTO(was posted in mustang forum)
Cut away from a New Camaro muffler that suffers from drone:
Ohh, look...on a G8 lol:
Other exhaust companies have been doing this as well it seems:
I had a plan to do this to my Mach 1 when I had it, but then I threw in Dynomax VT mufflers and they worked well enough I was done with the "anti drone" quest.
My L/T's, catless mids and dual 3" SW catback with no mufflers drone BAAAAD, so it would be sweet if I could make a catless/muffler-less system not drone. LOL
Thought? Opinions? Ideas? I would link the Mustang forum thread so people can read for themselves, but I don't know how mods like that.
Sorry this isn't another "what exhaust is the best to put on my (enter year GTO here)??" lol Hopefully this will get a little technical.
It's been around for a long time being used in intake tract silencers. There is a 13pg thread on a mustang forum where people have done this and came out with amazing results. This goes deeper than the mustang crowd too. Since researching, I have found it on Beemr forums,Audi forums and other "sensitive hearing" oriented car enthusiaites.
Quote from post in Mustang forum from the guy who started it:
"My magnaflow had the usual 2000 rpm drone, so I tried something a little different (I think) to get rid of it. The drone is now not just better, it is completely gone - the exhaust is downright quiet cruising at 2000 rpm. I read an article on the internet about "tailpipe resonance", and decided that this has to be the problem with aftermarket catbacks. They probably all have the same 6ft tailpipe mine has, which if the exhaust is at about 500 degrees, will resonate at 134 Hertz, which is the engine firing rate at 2000RPM. So I added a 134 Hz, 1/4 wave resonator to both tailpipes. Its just a section of pipe "T"ed into the tailpipes right in front of the gas tank. They are about 26" long each, which maybe a little shorter than ideal, but that's what fits in the available space. 26" must be long enough, because it sure as heck works. One end of each pipe is welded shut, and the other is T'ed into the tailpipes. If anyone is interested, I can try and post a picture."
Corsa of course promotes a RSC Technology in their mufflers which goes beyond this since they are able to tune the drone withing the confines of a muffler.
You would simply "T" off your exhaust with a centerline length of tube that you calculated and cap the end....done. My drone comes in at 1700 and stops around 2000, so I calculated based on 1750rpm giving me 29" of pipe needed.
How I plan to redo mine...mimic the Corsa single 3" but with a pipe "t'd" off. (not to scale)
On a Mustang:
On a GTO(was posted in mustang forum)
Cut away from a New Camaro muffler that suffers from drone:
Ohh, look...on a G8 lol:
Other exhaust companies have been doing this as well it seems:
I had a plan to do this to my Mach 1 when I had it, but then I threw in Dynomax VT mufflers and they worked well enough I was done with the "anti drone" quest.
My L/T's, catless mids and dual 3" SW catback with no mufflers drone BAAAAD, so it would be sweet if I could make a catless/muffler-less system not drone. LOL
Thought? Opinions? Ideas? I would link the Mustang forum thread so people can read for themselves, but I don't know how mods like that.
Sorry this isn't another "what exhaust is the best to put on my (enter year GTO here)??" lol Hopefully this will get a little technical.