Does anyone have this noise, first off I have test pipes and a true dual exhaust system. Seems like if you rev to 3K and let the RPMS drop down to 2K, I get this sound from the back, when inside the cabin it sounds like its coming from inside the lower part of hatch, when outside, it sounds like its coming from the muffler tips..liike a vibration humm noise, then it goes away once the revs get lower to like 1k.

Also happens when I'm driving say I'm in 1st and drive to 3.5K then slowly shift to 2nd while the rpms drop during the shift you hear it yet again however, if I'm running to hard to about 5K and shift you don't hear it, seems to only do it in lower RPMS.

I've put the car on jackstands and had my friend tap the gas while I was under the car, and it doesn't seem to be any thing touching the exhaust, I checked everywhere possible but the noise sounds like its coming from inside the muffler I held down every part I thought might cause the vibration still nothing...

Maybe this normal due to the large amount of flow I now have with TP and TD exhaust??

Let me know if your setup produces this sound.

 

I just have the HKS exhaust and I'm getting the same humming vibrations that your talking about from the rear especially when going in reverse or going from 1st to 2nd. I'm taking it in to the guy who installed it to see if he can fix it. Did you check the bushings?

 

Yup checked everything, I took some videos I'll put up in a bit.

 

Ok, heres a video to help better describe the noise:

Click here to watch Exhaustnoise

 

what exhaust is this? definitely doesn't sound right, sounds like metal hitting something, esp at lower rpm where the car shakes more. maybe get closer inxpection, examine all areas in which the exhaust/pipings could potentially hit the undercarriage? How about the exhuast tip? it looks mighty close to the rear bumper...

 

Trust me I checked everything, it clears all parts that would touch, its coming from inside the muffler... its weird!!

 

damn..maybe someone threw pebble in there?

 

https://my350z.com/forum/showthread.php?t=172819

is this the same exhaust?

 

Yup, seems that the exhaust was hitting the cross member at the back of the car, just dropped it and put washers on that sway bar and it was ok. Its just pretty close spot where the pipes sit. Seems to be a common thing with after market exhausts.

Also I wouldnt run Test pipes with this exhaust, it gets pretty loud. stock cats or high flow cats sound awesome with it.