Quote:
Originally Posted by heymanwatchthis
Topless - wonder what would happen if a pipe is welded between the 2 cans, connecting them? Would resonance go away?
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Lets all be clear on this. You never want any exhaust leaks in the system. Make sure it is absolutely tight. The sound from an exhaust leak is different from 2-3k acoustic resonance drone caused by exhaust tuning. Apples and oranges. The goal is a tight exhaust AND no 2-3k acoustic resonance.
To solve the resonance problem you need wave cancellation in the 2-3K drone zone. Sort of the same technology as the Bose headphones that cancel outside noise. A perfectly placed connector pipe that is the right length and right diameter might work. It will require math or a lot of trial and error. A noticeable drone or nasty exhaust note is an indication that resonance and acoustic standing waves are interfering with the free flow of exhaust gases. I have not yet seen a drone-free 2-can exhaust but it is possible with precise acoustic tuning.
Essentially Porsche engineers carefully tune the stock exhaust to cancel frequencies in the 2-3K drone range, reduce overall loudness from 110db to about 90db, and let the sweetness of the motor come through under full throttle. They spend a ton of R&D time and money to get the sound right because it is a big part of Porsche DNA. The stock exhaust is big and heavy but it works well. The best solution I have seen is to do the Pedro sport exhaust mod which retains the 2-3k wave cancellation while letting more sound out.
I hope this helps.