removing cats completely.
 

i decided to repost this in here since it was the proper area.

just curious.. if people seen gains of 40hp with the berks HFC has anyone done some dyno runs with no cats at all? or is there something computer controlled that messes up timing or a/f ratio because of 02 reading being different. i know for me personally there is no testing for things like that here in arkansas or any most other states. very few actually have epa inspections of exhaust gasses. and i know in my 2001 TA the difference from cats to high flows cats was just as different as highflow cats to none at all.

anyhow someone enlightened me on this please. because. i can have my own exhaust setup fabricated and if i can get away with the cats being deleted without something effecting the engine itself. im going to run straight pipes to a x-pipe back out to the stock muffler. im assuming like the ls1 in my trans am. im guessing it all boils down to getting into the pcm/ecu and changing something there. i know on ls1's you have to go in and turn off the readings from the back 02 sensors.

The words you should search for are "test pipes"

Nissan 370Z Forum - Search Results

Or, "long tube headers" :drool:

From the dyno results I have seen, it's not 40HP with HFCs. It's 8-10 (with testpipes), and around 4-5 for HFC's. The Cat back can net upto 20HP, and another 17 or so from a CAI.

So with ricer math (which seems to work on the Z34) you should see around 25HP from just a catback and HFC's, and around 30 with catback and no cats at all.

I'm not sure what the laws in Arkansas are. But here in Alberta Canada; if you remove the cats on a vehicle and get caught.... it's a $5000 fine. So performance gains or not, I would never do it.

That's just a law to scare people, and it holds true here as well. Non-issue in most cases.

LOL....:iagree:.......40hp = Ricer math...

I made 293.5 on a dynojet with nothing but test pipes, and it sounds awesome.

8-10 and 4-5 huh? how about 15whp? Thank you Red370, you're so f'in cool!

http://www.the370z.com/intake-exhaus...o-results.html

red, that avatar pic has gotta go man, its real fkd up

so are you saying im ugly?

dang red why did you change the pic i thought you looked super sexy!

I got a makeover, now I just look like James Dean, only sexier.

Not to be rude, but I really don't think you live here in Alberta. I'm in the repair and parts business. Have been for almost 30 years. I've seen people who remove their cats get fined. I've seen shops get fined as well.

You used to be able to get cat eliminator pipes (oem fittments). But here in Alberta, they have not been available for almost 30 years.

So no, it's not just to scare people. The law has teeth and has been applied many, many times. (Again, I'm trying not to be rude.)

As a lawyer, I have to agree with 6MT. The law has teeth and is applied (here in Canada).

I definitely don't live in Alberta. I've never heard of anyone getting a fine for removing their cats. I would think that it's aimed more at the shops that would do it rather than the car owner. Shops won't legally do it on street cars, but there's nothing to prevent you from doing it on your own. If you have an OBDII car in Texas they don't even visually inspect your exhaust when doing an inspection. If the computer passes it, you're done.

Truth.

What about when combined with a Cat back? Is it still 15WHP? If so that is amazing and hard to believe.

With most products you will see the most gains when adding them independently. The more you have done the less you will see from each one.

Agreed, however, couple the NA mods with a decent tune and you'll make significant gains in both hp and tq across the entire RPM range, look what the AP did for bluestyle, shyt was nuts.

exactly, even FIs HFCs only made an extra 5 hp with their CBE already on. Im sure if they had done a dyno with only HFCs it would have gained more. And if they had done dyno of their CBE with HFCs already on they probably wouldnt have the gains that they did with it alone. But I do agree the tune will bring the mods into alignment more and gains some gains.

or all the vendors afraid to show dyno results with only there parts. ;)

i was pulled over and sent in for inspection and the cop shop told me straight headers wasn't gonna cut it so i added some cats (clamped on of course ;) ) and threw out the ticket. man canada sucks it sounds like california only with crappy weather.

Edit: this was the old firebird i wouldn't dream of pulling that shyte in a foreign car here

no emission tests here in Arkansas. i love the south. though i was pulled over one day for driving open headers in my Trans am. got bored and what seafoamin the engine to clear out some carbon build-up. rofl i was making cars beside me vibrate :P