Exhaust Drone Fix
#13
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Yup Thunder has it dead on.
After i read through that whole thread over on that mustang forum, I started google searching branch resonators and learned that they are used in other applications to cancel a specific unwanted frequency.
I just wanted to throw this up on PT for anyone who is interested in learning something new.
The only problem we came across trying to do all the math is we couldnt figure out how hot the branch resonator would get because the temperature the exhaust is changes the speed that sound travels. I think we are a little bit off because it works extremely well when the car first starts up (cold) and when it gets up to operating temp it loses some of its canceling ability.
So I think my fix for that is Im going to buy some 2 inch inner diameter piping and cap the end and get a 2 inch exhaust clamp to slip over and clamp to the 2 inch outer diameter pipe. That way it will be adjustable and we can fine tune it since I cant figure out exactly the temp of the exhaust in the resonator.
Sorry for the long post, but Im at home recouping from my wisdom teeth being pulled and have nothing else to do..
After i read through that whole thread over on that mustang forum, I started google searching branch resonators and learned that they are used in other applications to cancel a specific unwanted frequency.
I just wanted to throw this up on PT for anyone who is interested in learning something new.
The only problem we came across trying to do all the math is we couldnt figure out how hot the branch resonator would get because the temperature the exhaust is changes the speed that sound travels. I think we are a little bit off because it works extremely well when the car first starts up (cold) and when it gets up to operating temp it loses some of its canceling ability.
So I think my fix for that is Im going to buy some 2 inch inner diameter piping and cap the end and get a 2 inch exhaust clamp to slip over and clamp to the 2 inch outer diameter pipe. That way it will be adjustable and we can fine tune it since I cant figure out exactly the temp of the exhaust in the resonator.
Sorry for the long post, but Im at home recouping from my wisdom teeth being pulled and have nothing else to do..
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#19
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This is the exact same sound reflecting technology that goes into corsa's mufflers, just done externally and probably ~500 bucks cheaper. look up corsa's website and look at the cutaway of their muffler, its the same principle
pretty cool if you ask me because you can tune your system to your own sound preference by using your own muffler and for specific drone rpm's
pretty cool if you ask me because you can tune your system to your own sound preference by using your own muffler and for specific drone rpm's
#20
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This is the exact same sound reflecting technology that goes into corsa's mufflers, just done externally and probably ~500 bucks cheaper. look up corsa's website and look at the cutaway of their muffler, its the same principle
pretty cool if you ask me because you can tune your system to your own sound preference by using your own muffler and for specific drone rpm's
pretty cool if you ask me because you can tune your system to your own sound preference by using your own muffler and for specific drone rpm's
The stock exhaust size on the jeep was 2.5" and we used 2" pipe to make the resonator. Home Depot had this really nice 90 degree bend 2 inch pipe so thats what we used.
The exhaust doesnt actually go into the pipe since there is no room for it to go since it cant escape. So the exhause is going to continue out like it normally would. Since its T'ed into the exhaust, there isnt and ducting that is forcing the exhaust gas to flow into the closed pipe. The only thing that is going on in the pipe is that it is producing sound waves because of the air that is being blown over the opening.