Active noise cancelling system on turbo racecar

With all the noise restrictions on the racetracks i am wondering if anybody has used a active noise cancelling system on his racecar yet?in my racecar i have a porsche 956 bi turbo engine where the turbo exhaust exits in front of the rearwheel and the distance of the exhaustpipe is only about 30cm! If ANC would work it would not change the backpressure on the engine because of mufflers it also would solve the space problem. Thanks in advance for any advise. Petr
 
maybe that's coming in the future, but active noise cancellation takes power and mass, things which racers don't want to deal with. It might be productive to do a spectral analysis of the exhaust sound to see if there is one particular frequency that is problematic. In which case, a helmholtz resonator is a relatively light and inexpensive way to actively reduce the noise.
 
A turbocharger itself is a pretty effective noise suppression device.
I allways tinkered the idea, bundle of snakes feeding twin turbo's. Then you get away with two small mufflers.. But unfortunate, wife said "That aint going to happen". So now she gets a big pack of mufflers in her GT40.
 
maybe that's coming in the future, but active noise cancellation takes power and mass, things which racers don't want to deal with. It might be productive to do a spectral analysis of the exhaust sound to see if there is one particular frequency that is problematic. In which case, a helmholtz resonator is a relatively light and inexpensive way to actively reduce the noise.
 
Intressting answer!i tryed to figure out the power needed for the system!depending on the speaker(i think pressure chamber speaker)and the very low frequency(~500hz) a speaker effiency of 10% might be reached!that said,a 100watt amplifier could reach a equal noise as the real turbo exhaust. Now make this350 watts to be shure and the equivalent power would only be 0.5 horse power.theoreticaly if you rotate the phase by 180 degrees to the real sound you should hear no sound at all.actually i just need about 10db to reach the tolerated level and i think mufflers would kill much more hp to take 10db off of the noise of my 600hp engine!
 
Intressting answer!i tryed to figure out the power needed for the system!depending on the speaker(i think pressure chamber speaker)and the very low frequency(~500hz) a speaker effiency of 10% might be reached!that said,a 100watt amplifier could reach a equal noise as the real turbo exhaust. Now make this350 watts to be shure and the equivalent power would only be 0.5 horse power.theoreticaly if you rotate the phase by 180 degrees to the real sound you should hear no sound at all.actually i just need about 10db to reach the tolerated level and i think mufflers would kill much more hp to take 10db off of the noise of my 600hp engine!
. This helmholtz thing is intresting and i can see how it works in a closed enviroment.but how would you place it in a racecar?could it work just besides the exhaust?
 
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