test pipes vs hfc's and exhaust question
 

how much difference between hfc's and test pipes is there in power? with the test pipes it makes the car have a more raspy (honda) sound and with hfc's it still has a good tone, is that correct? also, if i got 3'' test pipes and 3" exhaust isnt that not enough back preasure or something for the car (im not a mechanic and i know only a little bit about motors) im debating between hfc's and test pipes and exhaust size, whats worked the best for everyone? any info helps, thanks

https://my350z.com/forum/2003-2009-nissan-350z/197329-the-top-100-common-questions.html

there might be some info regarding your questions in it

i have read that before... i want proven facts and peoples knowledge and dyno sheets if they have them and i dont want to go buy 8 different sets of everything to see what does the best i want some info from people that have these things already and an 07 at that... i have already been in the HR section and there isnt too much there...

If you are NA, not much... I remember some dynos from the FastIntentions folks comparing their test pipes to hfc and they claimed 2-3 rwhp difference.

If you are turbo'd, huge difference. I know my boost was limited to 12 psi and about 420 whp with hfc (curve went to crap after 12 psi) and that shot up to a beautiful curve at 14 psi and 480+ just with the switch to test pipes.

IMO, test pipes suck though because of the fuel vapor smell. If you don't have a garage, then no big deal. If you park inside a garage, I would not recommend test pipes. Just getting out of your car will impregnate your clothes with fuel vapor - yuck.

I'm doing something custom now... ;)

damn, i wish i had the money for that right now... i gotta start with the small stuff for now... but yeah is bigger better? by that i mean bigger exhaust, i know it has more flow but since there is such low back pressure doesnt that mess up the motor?

Members are experimenting with the VQ35HR motor to see what works and what does not. Want a good direction for performance? I would do what this driver has done: https://my350z.com/forum/drag/317094-finally-hit-12-s.html.

Good for you, stand your ground. I have asked the same questions here and usually get the same smart a s s answers. This is about the least technical forum on the internet. I think it is because of the average fast and furious age of the owners here. One would think that the tuners would chime in just to boost their own knowledge. :icon20:

none you would notice

Is the smell of the TPs really that bad?

if you like the smell of raw exhaust its wonderful

if you dont, get cats

it's smells just like traffic.

TP's just aren't worth the $10k+ price tag...

+1 on that. Had one on my wrx, will never do again because of that.

I love my test pipes and will be getting another set here shortly, I am looking into crawford headers and test pipes.

i had helix test pipes and they rattled horribly to the point that i took them off....i wanna get HFC's and anyone that has them do u get the rasp and rattle when ur coasting or downshifting like i had with my testpipes?????????

I was in the same boat as you, except I have done alot of research on them for 1+ years. I have decided on Resonated Test Pipes; a Fast Intentions exhaust paired with Fast Intentions Resonated Test Pipes = :eek: . No rasp whatsoever. It all depends on the exhaust itself & quality of the TP's & resonators...some will produce more rasp then others.

The only thing that worries me is the smell plus the $1,500 dollar fine for removing cats thanks to our beloved California Air Resources Board (CARB).

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I wouldnt say it would mess up the motor but It probably isnt a good idea. If your askin about sound and raspyness of test pipes I definitely wouldn't recommend a 3'' exhaust unless you are planning on going FI in the close future. 3'' exhaust is very loud on NA Z's. I have test pipes and true dual exhaust and it is quite loud with 2.5" exhaust. I would probably recommend getting high flow cats if you are worried about exhaust smell and a little raspyness. They are a bit more expensive then test pipes but yield about 2-3 hp maybe? im guessing, not a noticeable difference. I will probably end up getting some high flow cats once I get tired of my test pipes due to the fact that they are loud as hell and will get annoying after a while. good luck

so if you get the high flow cats you will have no problem passing inspection?

2-3HP less than test pipes? Or they make 2-3HP in total?

test pipes probably make 2-3 hp more than hf cats. I would have to say test pipes will give around 10 extra hp or so compared to the stock cats, I definately could tell a difference, especially around 3k rpm.

test pipes are the yellow curve, non-resonated.