http://www.the370z.com/1401480-post3.html
First picture, zoom in the middle there is a flat metal part in black that crosses your mid pipes }==|==[ hope this helps:D

OMG I REALLY HOPE THIS IS ACCURATE.
1500 miles is a **** lot. Long drive INC. Luckily petrol is cheap here :P

As far as the pics are concerned, I doubt i have a pic, Ill just attach one found on the net of my exhaust
(i has the carbon fiber one :D not important but i want to throw it out there because they are pretty):happydance:

Thanks for that. figured it out , Will check it in the garage later
I feel a little hopeful right now
Thanks for that guys.

Will update later in the night if anything is wrong with the cross member.

You dont need a lift to check it, just grab one of the muffler tip by hand and bounce it up and down, if you can feel it hitting or it's making a clanking sound then that's your problem.

Nope.
Soild. No movement, No sound.
I feel better that my 'guy' doesnt do these mistakes,
But i am still going to take up the car on a lift and make him check again.
But as mentioned i guess there is a breaking in for these ART's.

They seem like a great company and i woudnt want to be calling these things 600$ fart cans which somehow landed up wrecking my akrapovic sound too haha
(ofc i can just remove them but these ART's are all shiny and pretty. so giving them the benefit of the doubt and will keep driving em for 1000 miles. OMG FAR AWAY)

The exhaust is the problem. When u open up the exhaust by removing the cats or installing hfc you can get that fart can noise and some serious vibration and rattles. A lot of exhaust companies don't take in consideration if this happens. U need a exhaust that will be more compatible with your art pipes.

Would changing my rear part of the exhaust help ?
I dont want to invest in a whole new CBE.


Anyway Update 1 - 24 hours after installing the HFC's

Under 3k RPM, Shes deep, Not great sounding but deep
The moment i push it down, Cheap fart can sound.Rattle to be more specific, Its not a sound created by pipes hitting each other, The sound is evident to be coming out of my exhaust tips.

It's the design of your exhaust, it just doesn't vibe with test pipes. Either get rid of the test pipes or get rid of the catback for something like FI or ARK.

Are you sure or assuming ?
I myself have thought about this but cant really be certain of this since i dont have much knowledge on this

Theres several dozen people with ART pipes here that love them, and have no issues while using other styles of CBE. Im not certain, but clearly you dont like the sound so you have to make a choice.

I think it has something to do with the single muffler rather than two. Similar to a stock design.

Will wait for a few days for it to settle in.
If not fast intentions here i come

I ordered non-resonated test pipes andni have ARK catback, I think its going to sound sinister.

How are the arks ?
I dont care much for loud..the akrapovics fall on the silent side but they are deep.
I would prefer a little louder but something deep.
How are the arks when it comes to that ?
Sheesh exhaust shopping again i guess

If the H-pipe diameters are larger, it may make "whooshing" or rasping sounds.

If you are hearing a raw rasp/rattle on decel in particular, around 2 - 2.5 K, it's the ART pipes. I don't know about break in -- they are supposed to be designed with Helmholtz resonators, or so I thought...

If the rattle is random, try adding some thick rubber washers to dampen some of the vibrations (heat resistant stuff, like for high quality intake tubing, cut into sections) where the pipes may be making contact with the cross member, as someone suggested.

Good luck! Getting the VQ motor to NOT sound like a spluttering pick up truck is no mean feat...

I had very modest rasp with resonated (standard) TP's plus the (poorly quality, frankly) Nismo S-tune Weldina -- switched to OBX wider Y and got woohsing -- I've heard of similar issues on some H and X's as well -- went back to the Weldina, which suffered several leaks over time...

You might swap out the H pipe for a take-off Nismo one, or see about adding additional resonators somewhere in the mix -- there's a thread or two on the subject.

I like it, very high quality and the Grip has Helmholtz resonators in the back like the HKS hi-power. I honestly dont anticipate a lot of rasp once when I install the test pipes.