Hey guys,

I got a g35 coupe 6mt. Just curious to know which is better to go with..test pipes or high flow cats. I dont really like the raspy noise from the testpipes. Does the resonated ones prevent it or no? Also which brand of high flow cats are good and produce the highest dyno gains? Please tell me any suggestions.. Thanks!

 

high flow cats. fast intentions or crawfordz.

but if you dont mind the smell of unburnt gas...

the test pipe route would be cheaper, go with fast intentions resonated test pipes.

as far as the difference in gains, it's not going to be a night/day difference between the two.

 

i asked the same question...get HFC

 

what ab the raspy sound with the test pipes? Does the resonator help alot or no?

 

SportCompact did a test, between HFC and Test Pipes you will only see about 1hp difference. however sound will be very different. You will have a lot more backfire/detonation with testpipes as the gas will cook off later in the exhaust instead of the cats burning it

 

subscribing

 

search for hero's review on the FI high flow cats... i just read it right now and i'm pretty much sold on it

 

You just read it... why didn't you post link?

 

haha my bad.. here you go hero's review.. https://g35driver.com/forums/showthr...light=cell+300

and FI's post.. https://g35driver.com/forums/showthr...ast+intentions

 

right on - thanks.

 

I have FI's HFC. Matched with their Catback = ZERO rasp/drone anywhere in the rpm range.

 

i have turboxs test pipes on borla exhaust-- NO RASP

 

Like hero said, but I would still pay extra for HFC so that you remain legal. Test pipes are not legal in any state.

 

True but if you don't throw a cell light then it will pass inspection in NY...not sure how it all works in other states.

 

test pipes will throw a cel on 03.5's and above if i remember correctly. 03's are fine.

but you can prevent the cel on the 03.5's and above with the non fouler mod.