I'm thinking of getting Hi-Flow Cats, but not ready to do headers yet... is it worth it? Minimal or noticeable gains?... or is it better to wait and do both (cats & headers) at the same time?

 

HFC and TP will give you somewhere from 8-10hp (in theory)

HFC will cost you around $350+ while TP cost like half. TP will give you a bit more hp gain due to no restriction.

 

what about code wise? which one will through one?


tommy

 

if you have an 03, 9/10 times it won't through anything with test pipes or hfc

anything after 03 and you're almost gauranteed to throw a CEL with test pipes, hfcs probably not but it's still possible

don't forget that test pipes will really lean you out, and since some people are running quite lean almost bone stock, they could in theory cost you power

 

with my crawford HFC, it never threw a light.

Just put on APS test pipes, and the light came on tonight! I installed in 2 days ago...

PS.. i have a 2004.5

 

Many 350Z owners run high-flow catalytic converters and the OEM exhaust manifold.


For saving time and install headaches, I recommend installing headers and high-flow catalytic converters at the same time: little point in getting under the car twice.

 

except for the fact headers take 5hrs to install, cats take 20minutes ^_^

 

thanks for the responses... I'm not really looking in the direction of test pipes... I have a G sedan (I can here the booos now) - with CAI, 1/2" spacer, Iso-Therm kit, Stillen exhaust, TS ECU F-flash (several other mods that don’t pertain to this thread)... it's an 04.5 so I'm not sure of any codes that would be thrown. Next mod is cats (and maybe headers)... I don’t plan to do the install myself so "getting under the car twice" is not an issue... I am aware of the price for product and cost of install - having all that been said, I'm just wondering if it's even worth while to do cats alone? Will I see a huge difference if doing cats and no headers than with cats and heads at the same time (difference in performance that is)?

Thanks again for your input

 

I heard from many people that you can hardly feel the diff. on a set of headers... simply look at Fujitsubo headers, you gain like 2HP at the top end and probably torque gain will be slightly more than other mods... so many people just can't be bothered fitting the headers which makes the car sounds louder too and cost a lot to fit them. I reckon stock headers should be fine though and if I want to make my car sound quieter, I might put back my stock headers...

cheers,

richie

 

I <3 my headers and noticed a godo gain from them

imho, the problem is most people expect this car to act like a viper - i.e., add on headers and gain 50rwhp/tq.

 

I think if you have the right combination of mods (cams, plenum, intake, cats, exhaust) and a good tune, headers are worth it (especially if you dont plan on going FI). Even comparing the design of the stock header vs. aftermarket you can see a HUGE difference.

I didnt notice my headers making much difference in sound...it was mostly my high flow cat.

brian

PS. i have crawford headers for sale! (used)

 

thanks! That's the kind of input I was looking for... Although I am after more TQ (my top end HP is real good), I think I'll probably go cats and skip the headers for now.

As for "loud" - with Stillen exhaust, I've become accustom to the loud factor - I'm told cats will probably give it a deeper/throatier tone, I'm hoping it's not much "louder"

Thanks again for the responses.

 

I have Kinetix cats with the stock headers. There was a very noticeable difference. I'd definitely recommend it. As far as headers go, for their cost as well as install time and cost, I can hardly see that they are worth it.

 

Cool - how do you like the Kinetix?... I was leaning toward Crawford - what was your deciding factor - price, performance?...

 

i am loving my kinetix

 

Just put my Crawford cats and my Jic y-pipe on the other day... sounds STOCK, no change in pitch/tone. I love it! No noticable gains either, but it makes me sleep better at night knowing I have it on and when ppl ask me what performance mods I have, I tell em, "Y-pipe and Cats" and they back off, hahahaha (because supposively it makes ur car uber fast.. yea right!) I haven't reset my ECU yet, no check engine light, car feels STOCK driving, sounds stock at WOT, but friends say I have a slight throatier grumble at high RPMs and my throttle feels smoother, I tell em in ur dreams. I currently still have the factory exhaust on, don't see the point in spending an extra $600 for 1-2whp, so stock it is, plus I like the stock quiet sound.

 

Reset your ECU and drive it hard! I definitely noticed a difference with the crawford cats! Your car should flow better. I think i gained alot more with test pipes though. Even with the high flow cats, crawford headers, and stock exhaust, my car felt like it was choking at High RPMS, but now it keeps pulling (aps test pipes). I still retain the good low end torque too! The only downside is the horrid rasp and smell. Car sounds nasty, but slap a couple turbos on there and you are good to go. My SES light comes on every two days too. Good thing i have a tool to erase the code.

 

headers do give you some gains, but with what Fujitsubo has quoted 2HP up the top, I just don't see the point (and yes, I have that in my car)...

High flow cats do help A LOT in terms of power though... so you should go for it.... and if you MAX out the N/A tune already (like what I have), don't let people talk you into larger cats again because crawford cats would do the job!!! I have been there... and those larger cats don't gain ANYTHING at all!

cheers,

richie

 

I think overall performance between the two is probably going to be equal. These made the car NOTICEABLY louder. I'd assume that the Crawfords do the same. So then it comes down to price. So I can't see spending any extra money on the Crawfords.

 

I like your style. Its nice to see someone with mods tell the truth. Just cause you have something on your car doesnt mean you cant give your thoughts. IMO there not worth the trouble. I guess if you just like to mod then go for it. But dont expect to feel the power.