On Friday my HFC's arrived along with my grounding kit from Sean (SxExCx). After I installed my grounding kit the fun started with the long install of the Berk's. I took them off one by one. The hardest part of the install was the removal of the stock cats. I ended up having to do most of the work in the dark outside in 37 degree weather. Luckily I had a bright little hobby light to work with. Any ways, after everything was all bolted up and back in place I reconnected the battery neg. and started her up. By the way my setup for everything is Z-tube, K&N drop in, 06-07 airbox, and MD 5/16 copper iso thermal spacer for the intake. Exhaust is Berk's HFC's and stock the rest of the way back. Sounds amazing, very happy with the sound output now of the stock exhaust with these cats. Idle sounds more deeper and WOT screams but with the stock sound that we all love. Now I just hope once I get my MD shockwave TDX2 exhaust there wont be any rasp since I've been reading a couple things that say there might be. Guess I'll have to wait to find out. I have a rattle coming from somewhere to at around 2200rpms. I'll fix that in the spring though. Prolly the heat shield cus thats what it sounds like.
Anyone looking to make your stock exhaust sound better and still be able to pass emissions I'd suggest to go with some HFC's. I love them

Nice! Did you feel and HP gain wiht the "butt dyno"?

How loud is it now at WOT? Is it a ghetto loud or slightly louder, deeper but still has the unique G35 stock tone?

Any weight difference between the cat's?

Have you heard any rasp with yours?

Any difference in exhaust smell/fumes?

will you post a vid if possible? Im in Cali, this should be smog legal...sniff test wise...anyone with info?
Thank you!

awesome... post a drive by vid if you can

nice job...too cold for me to be working on cars....

anyway...what is the outlet diameters of the Berks?? are they equal to the inlet diameters of your ypipe (stock)?? thanks...

Hopefully you won't have the same issue a lot of members have had with the cell material blowing out down the road and fvcking up your exhaust. I'm not a fan of HFCs in general when there are better options out there like the MD ARTs. Just my .02.

My Berk HFCs should be here today and getting installed this weekend (had to order new gaskets, hopefully they'll be here by Friday). We have pretty much the same setup, so I'm glad you like the sound of them. I'm pretty stoked about hearing my car once I get them on!

I have the berks with the tdx2 exhaust and I don't have any rasp.

My butt dyno is telling me yes and from what I've read somewhere ago the line they are suppose to add some hp and tq. We are talking about a stock G35 exhaust so you aren't going to get a "ghetto loud" lol. WOT sounds a little "louder" than stock. Still has the stock note but its just amplified now and sounds mean. There is a big weight difference. Let's just say this, one stock cat weights about as much as both my Berk's did. No rasp what so ever as of now. There is a slight smell of raw gas but nothing like test pipes. Hope I answered all your questions. I added a picture so you can see the over all size difference.

Tim how common is that issue? Or is it with just one brand?

I'd love to and trust me I would but I don't have a video recorder. My cell is a Droid 2 so I highly doubt you would be able to get a real feeling of sound. Something I have wanted to invest in but havent got around to doing. If I happen to buy one in the next couple of months I will surely post it on this post. Sorry for now.

I'm not 100% sure, but I think they are 2.5 and they match up perfect with my stock y pipe. Maybe someone can chim in on this one...

Glad things worked out for you. I drive a sedan, but definitely do like the exhaust note on the coupes. Good thing you were able to keep that. I'm currently looking to upgrade to the Fast Intentions resonated cat pipes. I just haven't found any reviews on them, mated with the OEM first gen. sedan exhaust. Let's see how my research goes and what I end up purchasing.

Btw, I had the same exhaust rattle around 2K RPMs that you mentioned above, ripped off my heat shields from the cats and y-pipe, all good now.

Is that with the Berk's or just any brand in general? I'd like to know this. The reason I chose HFC's instead of ART pipes is because I have to pass emissions and didnt want to have to swap out every year. I was looking at the ART pipes as well but you wont pass emissions testing with them. If it wasnt for that I would have went with the ART pipes, I can put up with the smell of raw gas. Thanks for your 2 cents though and seriously I would like to know about that issue as Im sure other people would too.

You'll be happy with the sound. I know I am.

Its nice to know that, thanks Then I will definitely be going with that set up then.

Good luck on the research, it usually does pay off in the end. If you cant find what your looking for then you can always ask for opinions on here. Im sure there is someone or a person that knows someone that has or has had that set up or close to it. I kinda of figured thats what it is. I'll have to do that once it gets warmer out though. Its prolly the cat shields cuz I took notice that the Berk's were really close to them on the back side. Thanks for the heads up.