370Z Nismo questions..HFC vs Test Pipe
 

Hello all..I have an 09 Nismo and have a couple of questions about High Flow Cats and other performance upgrades for my car.
Currently have 18,000 miles on it and recently installed a Stillin Gen 2 intake and want to continue to improve on a Great Car..
Questions.
1.How much HP gain can I expect to see from High Flow cats? 2.Any increase in sound? 3.Will test pipe make the check engine light come on?
4.How much increase from a Stillin lightweight pully change?
5.Anyone experience any Clutch slip problems?
Thanks in advance for your feedback

check out the exhaust threads...there's tons of info on this.

18,000 miles!

hell, i'll be at 16 by the time I get back to OK from Ohio, talk about doing some endurance testing, my VQ is holding up like a champ!

Just buy a HFC

With Test Pipes:
-you won't pass emission inspections, unless you're in one of the states that don't have them
-your car will be spitting a ton more carbon monoxide=bad for everything
-if you're ever idle and smell something bad, that's your exhaust

a HFC will give you almost the exact results in HP gain, although neither gives you much. But it still functions like a normal catalytic converter

Pfff who cares about carbon monoxide with our 245 grams already coming out

- you won't pass the emissions inspection no matter if you have test pipes or HFC
- lots of automobiles spit out ton of carbon monoxide. One Z with TPs is not going to ruin the world.
- there is a good chance you will get that smell with HFC as well.

OP: With TPs you will get some rasp at certain rpms no matter the exhaust type. HFC s dont have that problem.

I have a Nismo with the Berk TP. Haven't had a CEL come on yet, going on 300 miles.

I think the Nismo ECU is less sensitive than the 370Z base/touring ECU when it comes to mods.

I have Berk HFC's on their way for my Nismo, but have yet to be installed. Here are my thoughts on your questions.

1. You'll get your moneys worth. $500 is a cheap mod and you can't really go wrong.
2. Yes. See the exhaust clip thread. I don't think anyone has posted an OEM Nismo exhaust + HFC however.
3. Possibly. This is not an exact science. HFC's do have a less chance of making this occur however.
4. Probably not worth your money. I doubt you'll notice anything, but I could be wrong.
5. Not sure what you're asking.

you will pass inspections with high flow cats. I have it on my car, it passes every time. There is a big difference between a straight pipe and a pipe with a catalyst(s) with 02 sensors.

And I'm not singling out Z's. I'm talking any car in general. Catalytic converters are there for a reason, no reason to run test pipes.

And the smell with a HFC resembles a normal catalytic converter more than a test pipe

I put Berk HFCs on my Nismo as my first mod. Amazing, deep sound. Still wasn't the volume I wanted, so I upgraded from Nismo to Berk CBE.

You won't be disappointed with HFCs on the Nismo.

Cars that smell like burned gas from the exhaust will not pass the emissions no matter what. Crawford makes one of the most expensive HFCs on G35s and I have smelled the burning gasses standing next to the car that had those cats on. Any cat that is less restrictive than stock will not let the car pass emissions. I am talking about the VQ engine. In your case, civic might pass the emissions with HFC because it is already one of the cleanest burning gasoline cars on the market.

Well I was reading up more on HFC's, some will pass inspections, some won't. If they do, they will advertise it. The one's that are legal usually aren't in CA.