High-flow cats?
 

Anyone have a HFC front pipe? I'd like a little meaner sound without waking up my neighbors going catless. How much more sound do you generally get with one?

edit: topic fail.

The difference in sound volume between stock and a high flow cat is bigger than the difference between a high flow cat and no cat. Any cat will help with rasp too.

Do you already have a cat-back installed? I put on my front pipe (2.5" Perrin catted) with the stock exhaust first and it was definitely noticeable if you really listened, but no one else would know. The cat back made way more difference in noise (2.5" Perrin resonated).

Bear in mind the stock FP also has a muffler/resonator, while most aftermarket FPs don't.

Good to know. I've already got a P&L catback installed -- it adds some deep noise but is still pretty quiet. Perhaps the front pipe won't add much noise after all.

Stock FP has a helmholtz resonator, not a muffler. It'll only reduce rasp, not actually reduce volume.

A HFC front pipe, when compared to the stock front pipe, will noticeably wake up your catback. From experience.

i believe a high flow cat will be louder than the stock cat in the FP

It absolutely will (also speaking from experience), but the absence of the helmholtz resonator won't do anything for the volume.

I can confirm ! I went Greddy sp elite with little to no difference in sound
Invidia resonated frontpipe gave a very nice smooth sound
Then jdl uel header and overpipe WOW sounded like a pop can was loose in the muffler, lord of the rasp was born
Borla catback rasp gone but lord of OMFG thats loud was now born
then changed my invidia catless resonated frontpipe for a HFC thinking it would mellow out the sound, Wrong! the note has changed but still just a loud, good thing it doesnt stink anymore tho :)
The OEM front pipe REALLY quiets down the exhaust. im going back to it this is just to dam loud.

something else to note i found interesting, the inlet to the oem cat on the FP is very small, id say 2in, yet the rest of the FP is 2.5, also where it goes to donut gasket gets to 2.3in ?? i wonder if its worth chopping that silly little 2in section at the cat end of it and swapping it for a nice 2.5 with a nice thick flange ?

Before I switched to the n1 catback I had a shop cut the resonator off and just do a straight pipe and I really did not like the sound of it. I'm not sure if they just did a bad job or if that was really just the sound of it but there was a lot of rattle when starting the car.

Was it a helmholtz resonator (like the one in the stock front pipe), or was it an inline resonator?

Both will change the sound, but a helmholtz won't do anything for the volume. It will help a lot in reducing rasp/drone though.

I just ordered a JDL UEL header and JDL OP. JDL is making me a front pipe with a HFC and resonator. Will the car still be very loud? Rasp? Drone?

The rest of the exhaust is this: http://www.hks-power.co.jp/en/produc...rts/index.html

Anyone running a similar setup? This catback is supposed to be on the quieter side, at least that's what HKS says.

MagnaFlow sell a 2.5" high flow catted and resonated front pipe for our cars. I have one on my BRZ and it's barely louder than the stock front pipe. JDL and Nameless will make catted and resonated front pipes as well but they are made to order and more expensive.



Yes it will be loud but don't expect any drone or rasp. You chose wisely! :party0030:

that will be the best sounding exhaust known to man, that legamax sports exhaust is absolute perfection, from all the clips ive seen it has a very tiny rasp to it but while soundsing deep and aggresive, I have been debating for a longtime if i order this exhaust, how much did it cost you ??