Opinion: Berk HFCs with stock Nismo exhaust
 

Got the Berk HFCs installed and here's my honest take:

If you like the sound of the stock Nismo exhaust (which I do), this amplifies it a bit and it sounds great. I definitely feel like the car pulls harder at all engine speeds. I do notice a bit of rasp, but the stock cats sounded that way to some degree as well. In any event, I borrowed my buddy's heavily modded Evo X while my car was in his shop and, after hearing the turbo spool up in that and hopping back in the Z, I'd say the sound isn't all that far off. As such, it's not a horrible noise... just different. From what I've read on the forums, people say the rasp goes away with some break-in time anyway.

By the way, these cats are 10 lbs. lighter (total) than stock and the dyno charts shown here say they yielded 24 wheel hp for this particular car (***************************************/tabid/57/articleType/ArticleView/articleId/43/PageID/154/Berk-Technologies-Nissan-370Z-Downpipes.aspx). Not sure about the credibility of that site, but I definitely feel more power. Can't wait 'til my FI exhaust shows up to open things up even more... not to mention drop another 25 lbs!

Hope this helps anybody who's on the fence.

I have the same set-up in my Nismo with the Uprev tune. I tried the FI exhaust, but it was too loud for me. The rasp is gone but I have a heat shield or something making a noise that I have to get checked out. I also have the Nissan cold air intake. So I get more sound than stock, but a deeper growl too.

I was thinking about making this and an intake (perhaps tune) my only engine mods, but I was hesitant about the rasp (and other undesirable noises). Did you have to stuff steal wool in the O2 bung like I have read with other HFC?

I'm curious; did you use a dyno for your Uprev tune? What did it indicate as your rwhp with just the HFCs? Or did you have the intake at that time?

Nope. No issues whatsoever with CELs, but I've probably driven it only 100 miles thus far. That said, I don't believe people had that problem with the Berk or the FI HFCs... I think it's just with some of the off brand cats.

My dyno plots are over in the tune section. I had intake and hfc dyno and then the tune with the mods at P Tuning in Virginia. I was quite happy with the results. The FI would need a retune to get the most power. It was very nice and exotic sounding but too loud for me. But I'm almost 50. No CEL with the Berks and the tune.

I had Berks on my G35 and they were awesome! slightly raspy, made it sound a bit like an older, 06, m3. they really just amplified the "warble" that the VQ makes. noticeable power gain too :)

Had Berk HFC's on my 350z. Got a CEL after 5-6k miles. Good luck with yours OP.