A few days ago i installed a pair of kinetix HFC on my 05 g35 coupe, i did this because i thought it would be a cheaper way out,because my driver side cat was rattling now after all is done and the new HFC are in place there is a slight hiss coming from the y pipe i had three different muffler shops check for leaks,everything is well and no leaks. so then i contacted "kinetix racing" and they said it was normal due to the fact that all my exhaust is factory ,they said to upgrade the y pipe and it would go away...i want to retain the factory muffler and i really dont want a cat back any of you guys have this problem or does anybody no a fix? please help im lost right about now...

 

Search rasp on youtube. Is this what you mean?

 

Upgrade your y pipe to the hr type. Runs like $150 from forum vendors and keep the rest of your exhaust stock. That's the setup I am about to run.

On a side note, notice any gains in power? How does the exhaust tone sound now minus the hiss

 

the only time theres rasp if im at WOT and its not real raspy just a tad bit if you put the car on the lift and go to the y pipe ,and give it gas and when u let of the pedal theres a slight hiss echoing through there,shawo72 ,gain wise its a bit hard to tell maybe 5-8 to the wheels tops. i have 2005 track package they made very few, basically i have stiffer spring rates bigger sway bars and the 19s...thanks for the input shawno72 ps it sits 1 inch lower then sport package, just FYI not many people know about the "track package"

 

Wow I never heard if the "track package". I have an 05 coupe with the sport tuned suspension package. So the rasp is only when you let off the gas at wot or while accelerating to wot? And it's echoing possibly from the y pipe?

 

the rasp is at WOT while your driving, this hiss is when u left of the throttle in park or neutral in between 1800-3000 rpms,yea about the track package i found out becuase i went to the dealer to find out why my door jam said 17s and i asked him to run the vin and let me know what model the car was "well your car is called track package sir, and ima have to say i have never seen this" i thought maybe i had slight different ecu or maybe a different lift on the cams but its all suspension...o you had asked if i felt power today in the rain i turned off vdc and down shifted in to second at 40mph and floored it and the car got side ways it never ever did that before so im going to take it a lil easier in the rain. lol

 

Well that's pretty cool about the package. And since I'm lookig to buy a pair of Kinetix cats real soon I'll be Sub'd to find out the outcome.

 

so i have been looking for hr y pipe any suggestions? brands? it needs to have flex pipes because kintetix said my cats will crack if they dont have flex pipes...o and shawno72 are your oem cats ok? i may trade my cats in for oem used cats...

 

Yes my cats are ok. Try the forum vendors here. Marinelli motorsports has the hr y pipes your looking for.