Neat Quiet Exhaust Trick
Thread Starter
|
Senior Member
Joined: Jul 2007
Posts: 475
Likes: 0
Neat Quiet Exhaust Trick
I know most people here want the loudest most obnoxious exhaust they can find, but if you happen to want something a little quieter or have the annoying drone, here's a neat trick I just tried and it worked. I added a 24" tube behind the muffler over the differential and it made a significant difference in the drone of my Magnaflow in the 1,500-2,000 rpm range.
I'm pretty pleased with the change. Cost me $10 for a piece of pipe, $25 for the exhaust shop to weld it on.
Copied from another post but here's the summary.
I'm pretty pleased with the change. Cost me $10 for a piece of pipe, $25 for the exhaust shop to weld it on.
Copied from another post but here's the summary.
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.
Last edited by derrick929; Oct 1, 2009 at 12:14 AM.
Thread Starter
|
Senior Member
Joined: Jul 2007
Posts: 475
Likes: 0
Onelow, I'd guess maybe 30%, if not more, I was really pleased with it. I won't be adding the extra muffler now.
No, I have a tailpipe, you T into the tailpipe with a dead end tube. The sound enters that chamber(tube), reflects off the end of the tube, goes back into the tailpipe at 180degr from the exhaust note and cancels out the sound. Kind of like a speaker without a box, it doesn't make any noise because the sound waves in front and back of the speaker pretty much cancel each other out.
This isn't mine but it'll help explain what I'm talking about. Shape or direction does not matter since sound turns the corners. It can be a direct T off the mail pipe or it can come off and turn, either way it works, doesn't matter because the sounds waves still hit the end of the tube and bounce back.
Not quite the newbie..
This isn't mine but it'll help explain what I'm talking about. Shape or direction does not matter since sound turns the corners. It can be a direct T off the mail pipe or it can come off and turn, either way it works, doesn't matter because the sounds waves still hit the end of the tube and bounce back.
Not quite the newbie..
Last edited by derrick929; Oct 1, 2009 at 12:33 AM.
Trending Topics
Thread Starter
|
Senior Member
Joined: Jul 2007
Posts: 475
Likes: 0
It does quieten it overall a little, but mainly that annoying drone at highway speeds. You can still hear it when your getting on it.
Last edited by derrick929; Oct 1, 2009 at 07:37 AM.
Thread Starter
|
Senior Member
Joined: Jul 2007
Posts: 475
Likes: 0
No affects on performance, many exhaust systems actually come with these things already built onto them. It is just a hole in the side of the exhaust, most of the flow just goes right by it. It's been tested quite a bit in the research I did, it didn't have any affect on performance at all.