removing cats completely.

jtown82 · 03-30-2010, 11:23 AM

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.

vipor · 03-30-2010, 11:26 AM

The words you should search for are "test pipes"

Nissan 370Z Forum - Search Results

Or, "long tube headers"

tjlazer · 03-30-2010, 11:45 AM

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.

6MT · 03-30-2010, 11:47 AM

Quote:

Originally Posted by jtown82

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.

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.

vipor · 03-30-2010, 11:49 AM

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

Modshack · 03-30-2010, 11:52 AM

Quote:

Originally Posted by tjlazer

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.

LOL....

.......40hp = Ricer math...

NYBladeZ · 03-30-2010, 12:24 PM

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

Red370 · 03-30-2010, 12:35 PM

Quote:

Originally Posted by tjlazer

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.

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

Berk HFC dyno results

NYBladeZ · 03-30-2010, 12:51 PM

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

Red370 · 03-30-2010, 12:58 PM

Quote:

Originally Posted by NYBladeZ

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

so are you saying im ugly?

NewlyIMPORTed · 03-30-2010, 12:59 PM

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

Red370 · 03-30-2010, 01:03 PM

Quote:

Originally Posted by NewlyIMPORTed

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.

6MT · 03-30-2010, 02:21 PM

Quote:

Originally Posted by vipor

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

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.)

budlight · 03-30-2010, 02:28 PM

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

vipor · 03-30-2010, 03:48 PM

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.

03-30-2010, 11:23 AM	#1 (permalink)
jtown82 Base Member Join Date: Mar 2010 Location: southern Arkansas Posts: 158 Drives: 09 chicane yellow Z Rep Power: 15	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.

03-30-2010, 11:26 AM	#2 (permalink)
vipor A True Z Fanatic Join Date: Aug 2009 Location: Euless, TX [ DFW ] Age: 41 Posts: 13,531 Drives: Nismo 09-0183 QAB Rep Power: 48	The words you should search for are "test pipes" Nissan 370Z Forum - Search Results Or, "long tube headers" __________________ 2009 NISMO # 0193 \| QAB \| Albums! \| 05.04.10 (Dynojet) 291.94hp/248.28tq Oil Cooler (DIY) \| Custom Headlights \| GTSPEC Braces \| F.I. Long Tube Headers

03-30-2010, 11:45 AM	#3 (permalink)
tjlazer A True Z Fanatic Join Date: Dec 2009 Location: Tacoma Age: 52 Posts: 2,496 Drives: Z34, R35 Rep Power: 19	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. __________________ 2009 370Z Monterey Blue,Nismo Conversion,RE-11's, K&N Typhoon intakes,Blue Kickplates,Homelink,FI 18" CBE,ERZ HFCs,Hotchkis sways, Swift Spec-R, EVO-R Highwing, UPREV Last edited by tjlazer; 03-30-2010 at 11:49 AM.

03-30-2010, 11:49 AM	#5 (permalink)
vipor A True Z Fanatic Join Date: Aug 2009 Location: Euless, TX [ DFW ] Age: 41 Posts: 13,531 Drives: Nismo 09-0183 QAB Rep Power: 48	That's just a law to scare people, and it holds true here as well. Non-issue in most cases. __________________ 2009 NISMO # 0193 \| QAB \| Albums! \| 05.04.10 (Dynojet) 291.94hp/248.28tq Oil Cooler (DIY) \| Custom Headlights \| GTSPEC Braces \| F.I. Long Tube Headers

03-30-2010, 12:24 PM	#7 (permalink)
NYBladeZ A True Z Fanatic Join Date: Apr 2009 Location: New York Posts: 2,158 Drives: Lotus Exige S Rep Power: 20	I made 293.5 on a dynojet with nothing but test pipes, and it sounds awesome. __________________ 2009 Carbon Fiber/Red 370z aka Trish: Sports Package, Meisterschaft full catback, Fast Intentions Longtube Headers, Injen Long Tube Intakes, UpRev Tune: Sold 2008 Lotus Exige S Club Racer aka Bella, always leaves me smiling

03-30-2010, 12:51 PM	#9 (permalink)
NYBladeZ A True Z Fanatic Join Date: Apr 2009 Location: New York Posts: 2,158 Drives: Lotus Exige S Rep Power: 20	red, that avatar pic has gotta go man, its real fkd up __________________ 2009 Carbon Fiber/Red 370z aka Trish: Sports Package, Meisterschaft full catback, Fast Intentions Longtube Headers, Injen Long Tube Intakes, UpRev Tune: Sold 2008 Lotus Exige S Club Racer aka Bella, always leaves me smiling

03-30-2010, 12:59 PM	#11 (permalink)
NewlyIMPORTed A True Z Fanatic Join Date: May 2009 Location: Kennesaw, GA Posts: 1,109 Drives: 11 STI Sedan Rep Power: 18	dang red why did you change the pic i thought you looked super sexy! __________________ 2011 WRX STICobb Accessport, Nameless Performance exhaust, COBB SF Intake, COBB downpipe, 20% tint, Work Emotion XD9's

03-30-2010, 02:28 PM	#14 (permalink)
budlight Base Member Join Date: Mar 2010 Location: Alberta Posts: 9 Drives: hard Rep Power: 15	As a lawyer, I have to agree with 6MT. The law has teeth and is applied (here in Canada).

03-30-2010, 03:48 PM	#15 (permalink)
vipor A True Z Fanatic Join Date: Aug 2009 Location: Euless, TX [ DFW ] Age: 41 Posts: 13,531 Drives: Nismo 09-0183 QAB Rep Power: 48	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. __________________ 2009 NISMO # 0193 \| QAB \| Albums! \| 05.04.10 (Dynojet) 291.94hp/248.28tq Oil Cooler (DIY) \| Custom Headlights \| GTSPEC Braces \| F.I. Long Tube Headers

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