What the heck is that sound?
 

I have a GTM stg 2 TT kit on my Z. I recently had GTM 3" downpipes installed along with my new 3" FI exhaust with external WG (non re circ). Since then I notice this really loud noise coming from the driver front side of the engine when I'm cruising and accelerating at highway speeds. I know what you may be thinking - it's just the sound of the engine as the external air vented WG open. However I'm pretty sure it's not that since it makes a sound that is distinct from the engine noise and it does it at low or no boost.

It sounds to me like a spitting exhaust leak but I don't have a trained ear for that sort of thing. My mechanic spent 15 hours trying to get the gtm pipes to mate with the FI so I'm wondering if he didn't do the job properly. Tony at FI told me that the GTM downpipes usually have fitment issues so I was expecting it would be a PITA for my mechanic (which it was).

Could you guys listen to the noise in the video and let me know what you opinion is? Am I on the right track? I've already had to have my mechanic tighten the exhaust assembly twice but it's not fixing the issue.

Here's the video:

http://youtu.be/c7LliqOFrqU


NOBLE

15 hours??? was he in a straight jacket the whole time?

Sounds like a leak to me.

:confused: its hard to tell almost sounds like maybe a heat shield or something vibrating a little could be a small leak as well

Yeah, the leak sound is driving me nuts. My mechanic told me to bring it back to his shop here in Calgary. He thinks its probably the same leak that he tried to tighten down before. It's the 3rd try he'll need to fix this, so I'm starting to wonder if maybe its something else. The gremlins (rattles, leaks etc) in a heavily modified car can be enough to drive a guy nuts. The feel of a TWIN TURBO Z makes it all worth it in the end :happydance:

Just a heads up to anyone buying the GTM 3" downpipes. They don't really mate up straight with the FI exhaust, so it takes lots of messing around. It sounds like others haven't had much issue installing it properly, but my mechanic is having a hell of a time with it. Fast Intentions includes a written warning in their 3" exhaust shipment warning of the fitment issue with the GTM pipes. Mine are way out for sure.

Tony - will Fast Intentions consider development of their own 3" pipes some time?