resonance muffler

[Geoff Heise]

Have a Sydney based Autohaus Hamilton

Install on cayman 2007 2.7litre tiptronic

Fabspeed muffer, air intake and cat convertor ECU upgrade



The interior of the cabin resonates ? (standing wave)

At 2000rpm



When pulling at2000 the resonance inside the cabin is insufferable

Either side of 2000 there is no problem Sounds absolutely fine



Question is there a solution?

Trialed lengthening the tips - no benefit



Does the muffler need baffle plate to stop the standing wave?



Should there be sound insulated mountings of the pipes?



Am prepared to simply re install the original muffler as doing my head in.



However are the other components a potential?



My feeling is tail pipe - uninterrupted length (standing wave)

[scwaters]

Harmonics.  Its the price you pay for almost all aftermarket exhaust systems, no matter how much you spend.  I have a Capristo and it has a 500 RPM harmaonic range.