i was wondering if it would be smart/fine to run HFC (probably Berks ceramics) with the stock exhaust? I'm planning on getting the HKS or the Nismo cat-back exhaust in a few months closer to summer, but i wanna run with just HFC if it'll boost power and make it sound a bit better. So that way i'll notice these and then the exhaust, instead of noticing the exhaust and a very minor change with HFC after it. has anyone done this? how does it sound and would it provide power gains with a deeper tone, and work even better with the HKS/Nismo in a while? This way i can spread out my mods more and notice each one separately. Input is appreciated!

 

if you want to feel each of your mods seperately i would get the exhaust FIRST and THEN the HFC's...however in regards to your main question, i personally wouldn't do it, but that is just me. im sure someone on here has done it...

 

I have that setup, berk and stock exhaust. I love the tone now. I was worried at first, but it turned out very well. Not sure what exhaust would sound better, still researching.

 

if you are looking for a significant increase in sound tone and performance, then the hfc's are a waste of money. you will hear very little difference and the butt dyno will yield nothing.

 

If you run the HFC's with headers, you will notice some gains (I ran headers, HFC's and stock exhaust for awhile). Now with the Amuse exhaust, everything is really put together. Start at one end of the breathing chain and work your way towards the other for nest results.

 

Get test pipes with your stock exhaust. It sounds mean!

 

well i don't want to do test pipes, but why is hfc with stock exhaust a waste of money Nexx? i thought they provide good gains. i know it wont change the sound too much, but i guess slightly is fine as long as i can atleast feel difference in power.

mw9 - you say the tone got slightly deeper, which is good. but how is the butt dyno? felt an improvement in power? cause i've read that HFC/TP are noticeable change in power...but i'm getting mixed responses..

 

Why not skip high flow catalytic converters and get test pipes?

 

well i dont want any rasp what so ever, and i go to school in college station, texas. small town where cops are horrible. don't want to chance it there too. and i plan on pairing this with either HKS exhaust or nismo, so dont want rasp at all.

 

I too, have been considering which way to mod my HR 1st, as far as exhaust goes. At this time, there are no headers available, but from what people are saying in this forum is that the headers are pretty good stock, already.

I then thought about HFC's 1st, or cat back 1st. It seems, as someone else has mentioned, that the factory cats are THE most restrictive part of the exhaust system, period. So I plan to go with the Berk metallic HFC's or TP 1st, and then go with the exhaust last.

I have heard several G35's and Z's with the factory exhaust system, using HFC's, and there is a noticable increase in the volume of the factory exhaust tone. With TP's, even more noticable, but depending on the set up, TP's can cause a "raspy" type sound, which is still noticable with the factory exhaust on.

To some, it may seem backward to install a HFC or TP 1st, before putting on an aftermarket exhaust system, but I believe IMO that by changing to HFC or TP 1st, you'd be getting rid of a bottle neck in the system. I don't think it's a waste of money, because if you want a complete exhaust system, you'll have to get the HFC's or TP's at some point in time anyway. And the OP mentioned that he is planning on getting an aftermarket exhaust later anyway.

So I say go for it. Check with Berk though, because you mentioned ceramic HFC's, and I think they mentioned the metallic ones were lighter with better longevity and near TP flow. Good luck.

 

ahh yea i guess i'll look into the metallic ones too! but just the main question is, if you do HFC without the catback (for a little while) how would it feel performance wise and how would it sound. Cause this way, i could maybe change the tone (very slightly i know) and still feel the performance boost for the time being until i get to the catback (big sound difference and hopefully performance boost again). but Nexx said it'd be a waste of money and mw9 has the berks w/ stock exhaust and is happy.

so to Nexx, why is it a waste of money? like what parts am i wrong in?

and to mw9, how was ur experience? you said sound wise it got a bit deeper, nice and subtle im assuming like i want, but power wise? also did u get the metallics or ceramics?

thanks i appreciate the responses!

 

HFC on stock exhaust.... *raises hand*

 

wired, could you elaborate on that and maybe help with my questions above? thanks

 

i had this setup and is fine , the only problem is the stock y pipe is very restricted

 

Dude, get any one of the said exhaust upgrades you can afford, in any order you like. What you're seeing here are people's personal preferences. There are no wrongs or rights. What you need to know is that the cats are the most restrictive part of the system, then the y-pipe, then the muffler out back. This is really not rocket science, don't make it any more complicated than it needs to be. HFCs are a good alternative to test pipes, with most of the hp gains, no stink or rasp, and good for the environment (well, not as bad).

 

It depends what 350z you have.

On the non-revup which has no variable timing on the exhaust, I didn't see much of an increase in power on the dyno. Test pipes may be a different story though.

The sound definitely gets louder. The kinetix cats also seem to rattle a bit when the car is cold.


Due to the relative ease of install/uninstall I'd recommend test pipes. When inspection time comes, put the stock cats back on.

Resonated test pipes usually sound much better than ordinary test pipes.

 

do any of you guys have drive-by clips of the stock w/ HFC?

im not completely happy with the Nismo exhaust. The stock exhaust was much louder down low. Meaning, with the stock exhaust it was much louder moving from a dead stop whereas with the Nismo its barely audible. I care about this because most of my driving will be in the 2k-2.5k RPM range (NYC). I can only hear it if im in the 3k RPM range.

 

how is the craftmanship of the berk HFC?? they any good..i kno the catalyst is high flowing..but is the fitment good? cuz they r cheaper than alot of other HFC out there! thanks!

 

stock exhaust w/ HFC's here...not a bad sound...but the Kinetix do have a little rattle when cold....I notice a hint of rasp at the top of the gears as well... Gonna swap out the silly OEM gaskets (thin pieces of metal tacked together....hardly a gasket IMO) to see if that's part of the problem.

 

thanks for responses. i have the non-revup. I want to do this, but want to make sure i should feel atleast a bit of power upgrade. I know it'll be more when i do the full catback, but point of me doing this earlier, would be to feel how the cats feel without the catback. Just trying to get an idea so i won't get these and feel no power difference and barely any sound change (dont mind sound, cause that'll come with the catback).

WTX - did you feel any power diff with the HFCs?