I added the HFC later, I got my FI exhaust around June 09, then I got my HFC installed on around April 10. After the installed I was expecting the car to sound louder, but to my surprise it wasn't much louder. It sounds really good, I did it more to allow better air flow, since the Cats, are like a bottle neck. You will be very please with the sound, also the HFC are lighter the CATS on our car. The install was also very easy.

 

no. theres a thread in the intake exhaust section.

I did it the other way i had FI HFC first then added the FI exhaust later. I have the round catback though which is supposed to be louder than the intimidator. anyway when i added the exhaust i got drone. exhaust has been on for 5k and i swapped to md art pipes and still have drone but its a little less. idk what will happen to you just adding my experience.

 

I have the FI intimidator with the stainless round cans. It was crazy loud at first and had drone in the 2000-2800 range. Now that it's broken in (took me about 15k miles) I can say from experience it sounds like stock but louder, no drone at all, and is very stock-like unless I accelerate hard. That was last week. I just added the mrev2 Fri night and everything is sounding a bit louder now but still no drone and very happy.

 

15k mile to break in? seems a little long lol. but ya drone is the only thing i hate with this setup (same rpm range). if it goes away at 15k miles i'd be pretty ecstatic (or maybe pissed because by then it's time for a new car)

 

Yeah... it chilled out a lot sooner than that but around the 15k mark it got really tame in comparison. I was super happy when the drone stopped though. Not that it was too bad for awhile there before it stopped, but none is way better.

 

No.

 

One thing I did realize between the Berks and Fast Intention is that Berk uses the stock mount to support the exhaust when Fast Intention doesnt use the bracket at all. IMO that sucks cuz now all the weight is put on the headers. Has anybody come across any problems with the lack of support on the CATS after installing HFCs. I think I am gona make my own bracket if I do purchase FI HFCs.

 

the only reason the OEM cats used mounting brackets, is they weighed a ton.

 

Hey guys when i go to install my HFCs ive heard it would be a smart idea to buy the oem gaskets instead of using the ones that come with the Cats. Infiniti wants $55 bucks for the gaskets which is crazy but if im saving problems down the road ill just put out the money.

 

i've read its common to just reuse your old ones. they will work fine.

 

I used the gasket that came with my FI HFC, going on a year with no problem.

 

OMG, finally got mine on and i LOVE them. totally quieted down my lower RPM drone

 

How quiet are they? I figured they should be about as quiet as the OEM cats.

 

def not as quiet as OEM, OEM has 4 catalyzers. these only have 2 plus the 2 resonators. oh, and i just passed smog w/flying colors

 

vids or it didn't happen lol