Weird Hissing/Air Noise??
 

Don't know if this has ever been discussed before but i have a question. OK this is my setup:
-Stillen Gen 3 intakes
-FI non-resonated exhaust
-FI test pipes
I had the exhaust for about year, i then still wanted it louder. So after I installed the FI test pipes, there was an immediate hissing type of noise when u let off the gas, it sounds like pressure releasing or something of that nature. Is this normal or has anyone ever had this same thing? Also, could it be that I need to get the car tuned after having all that done? Any help would be awesome. Thanks!

It's normal with this motor.

happens with VQ engines. HFCs and test pipes will make the noise.

2X Yep, normal.

OP: It is quite normal to hear a hissing sound on deceleration once adding high flow cats or test pipes. It is the natural harmonic of the VQ37VHR motor. The sound is more prominent once you remove your restrictive OEM catalytic converters.

Please give me a call if you have any questions.

- Kevin

Thanks guys for the answer! I'm glad..now to the second part of my question. How beneficial will an UpRev tune be for this setup?

You'll definitely see benefits from a tune.

The tune will smooth out the bumps in the power band, A/F ratio, and a few ponies on top. You'll also increase fuel mileage, ONLY if you keep your foot off of the loud pedal. When you get the tune. Don't raise the rev limiter, and have the fans kick on sooner.

Yeah I've noticed a few little spots where there seems to be a lag in the throttle. Not bad but I've noticed it. Thanks for the advice! Was thinking of taking it to Z1 Motorsports, if you've heard of them?...

.... was that a serious question? please let that be sarcasm lol :roflpuke2:

Newbee

My thought exactly ^^

Normal for the motor.


/thread