HFC Cats
 

Do they really add HP and apprx. how much?
Can you really notice already having 334 HP.

I have only installed Invidia Gemini

Just wondering if:

Will it sound better? I would not mind a bit louder actually

worth the cost?

Thanks

Cost/Power Gains/Sound will be different with just about any HFC built for these cars, there are many many many threads on this subject, search the site using google simply adding "The370z.com" after your search will bring you here

Dont expect more than 10-12HP, your "Butt" dyno will not tell a difference

Berk/FI seems to be fan favorites given sound and power gains and price

I have the Gemini installed as well and recently installed the Berks HFC and it gave it a much better tone and overall sound and its a bit louder but for performance I didn't actually notice any real difference

louder sound = yes

HP increase = minimal, maybe 5+ ponies more

So little gain for High Flow Cats.?I thought over 15 Bhp gain.?

Unless you have long tube headers there is no way you have 334hp. Just sayin.

If you're worried about spending too much, why not try test pipe? Yes, it'll be louder but it's less than half the cost of HFC. Plus, TP has a better gain than HFC.

Adding HFC to your Invidia will probably add around 4~7 hp. Not significant but nevertheless it'll increase power and sound. All in all, I'm betting 305 WHP with your exhaust set up. You can try tuning it after which can get you a bit more power.

the hissing sound will get way louder...and more rasp...but you get used to it

HP - Factory set up for coupe vs Nismo
 

2013Z.. says 332 HP for coupe and 350 HP for Nizmo

so, public school math 332 + Invidia Gemini exhaust (2) = 334 HP

Didn't say I graduated - LOL

Just saying..

I am leaning toward the Berk.. everybody does the F.I. - i like to be different!

The motor is 332 at the crank. Aftermarket parts are measured in whp. You're probably at 280-290 whp. Cats will add another 10ish whp. Cats/tp, intake, exhaust and tune will get you 315-330whp depending on dyno. You'll absolutely feel that, plus the tune has a lot of other benefits (fan control, throttle response, etc.).

As others have said, just slapping HFCs on the car won't make a lot of difference HP-wise. But, combined with some relatively inexpensive intake mods (search is your friend; see Array's tip above) and a tune, you should see a definite increase in smiles per gallon.

figure this would be a good place to ask this question. what about going from HFCs to test pipes? I have a set of AAM non-res test pipes waiting for install

A few hp, probably not worth paying labor to swap. If you DIY, not the worst idea if you're trying for every last hp. Money would be better spent putting it toward gears on a NA build.

I'm doing it myself. I bought them to lock in a sponsorship so I may as well install them.

Still not sure if I want to stay NA and do gears or go FI eventually

If you've already got them and you live in a state where emissions isn't a problem, go ahead and DIY.