What up,

I recently purchased and installed Kinetix HFCs on my 2006 G Coupe and had what I think was rasp. The exhaust is stock other than the hfc and it sounded like a rattle can was under my car any time I went WOT where revs exceeded 4K rpm. The noise was so loud and terrible sounding that I took them off and put the stock cats back on which fixed the problem.

I'm considering getting the Invidia Gemini exhaust, so my question is does anyone on here run Kinetix HFCs & Invidia Gemini Combo? Do you have any rasp problems or rattle can sounds with that setup? Was the exhaust too loud? I really would like to incorporate the HFC's, the power gains were too good lol. I'm open to suggestions, not looking for anything too loud or ricey and want to keep in the price range of the Gemini. Thank you!

 

Sounds like you have an actual RATTLE, sound should not be coming from under your vehicle. I'd probe around for a broken exhaust hanger or something, make sure it all bolted together correctly and the gaskets are intact, etc.

 

I should have been more specific, it’s not a rattle but rasp happening within the exhaust somewhere. This only happens when I go WOT over 4K rpms underload. I can slowly rev over 4K rpms at partial throttle and not have the problem happen. I also have tried test pipes and it was even worse with those on. And to be sure I’ve removed the heat shields and checkd all bolts. I think it’s common to have rasp with HFC and stock exhaust, that’s why I was considering the invidia gemini. It’s sort of difficult to describe the sound but I tried my best haha

 

You're right about the results of adding HFCs to the factory exhaust! There's so much restriction in the OE cats that once you let it loose, it's like putting 3lbs of dog poop in a 1lb can! I suggest rather than the Invidia system you opt for the Exotic Speed R1-T exhaust, several members here run it and love the sound.
Gary

 

Yeah that does sound pretty amazing... damned shame it's not compatible with RAS

 

Damn sounds awesome. How’s the drone? Is it too loud or bearable? Lol

 

I ran the kinetix HFC and Invidia gemini for a couple of years and it sounds really amazing. Not a ton of rasp at all with a nice 'racey' VQ sound to it and the highway drone wasn't too bad at all. This was ran both N/A and supercharged with good results.

Here is a video with some exhaust sounds later on when Jon took it around the parking lot.

I recently swapped to single 3" and the sound is MUCH louder, but it's a weekend car.