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LT5 Mods that will still pass CA emissions??

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Old 01-25-2018, 09:15 PM
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BlackRocket
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Default LT5 Mods that will still pass CA emissions??

It seems that with the NOX levels lowered in Cali...the LT5's are barely squeaking by.

Can anyone that is familiar; list the mods that will allow better performance while still passing CA smog?

I would assume intake and head porting would not affect the emissions?

I have heard from others that Haibeck can burn a smog check chip as well as a performance chip.

Shorty headers with pre-cats? Does anyone make LT5 shorty's?

Obviously cams would be out of the picture.

What about larger displacement?

Lastly, 4.10 gears and an aluminum flywheel should have no factor.

Thanks!
B-R

Last edited by BlackRocket; 01-25-2018 at 09:17 PM.
Old 01-25-2018, 09:53 PM
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Z51JEFF
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Any mod needs to have a C.A.R.B number or it’s not legal to use in Ca. No headers were ever certified so no headers. A catback system is certified so you can use that. To give you an idea as to what your up against I just smogged my bone stock with 24,000 miles and it barely got by the MAX Nox level @504 when the max is 545. Not too much can be done in Ca as far as mods go. Marc H can work some magic with a chip if needed.

Last edited by Z51JEFF; 01-31-2018 at 09:25 PM.
Old 01-25-2018, 11:04 PM
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BlackRocket
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Maybe a quick trip to Infineon Raceway to get some of this...





Here's some good input on attempting to control Nox...Last thread is very informative.

http://www.eng-tips.com/viewthread.cfm?qid=44564
Old 01-27-2018, 03:33 AM
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cruban
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Actually you can squeak by with headers if you you have a 92 or older since the cats are welded to the exhaust manifolds are ARE discontinued. It will cause a trip to the smog ref each time, but you can if you want to spend the time.

Originally Posted by Z51JEFF
Any mod needs to have a C.A.R.B number or it’s no legal to use in Ca. No headers were ever certified so no headers. A catback system is certified so you can use that. To give me ou an idea as to what your up against here I just smogged my bone stock with 24,000 miles and it barely got by the MAX Nox level @504 when the max is 545. Not too much can be done in Ca as far as mods go. Marc H can work some magic with a chip if needed.
Old 01-27-2018, 07:03 AM
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Z51JEFF
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Originally Posted by cruban
Actually you can squeak by with headers if you you have a 92 or older since the cats are welded to the exhaust manifolds are ARE discontinued. It will cause a trip to the smog ref each time, but you can if you want to spend the time.
There is atleast on car running around that has headers in Ca and from what I remember at one point no cats were available and the only option was headers with aftermarket headers by that a stretch getting to that point. My 91 has the cats welded to the manifolds from the factory I believe. If a company in the past would have done a he certification on a set of headers I’d have a set on my car already. To the OP,don’t think that leaded 114 Octane gas would be too kind to a set of catalytic converters.
Old 01-27-2018, 01:00 PM
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Jagdpanzer
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No problem getting my 94 under 500 NoX with a modified chip that kicked in the EGR at 13 mph. Mods: SW headers, 63mm TB, ported top end, Magnaflow cats, Corsa exhaust. I live in in Northern Virginia which has as tough emission limits as anywhere. Just passed my last test. No more for after 25 years.
Old 01-27-2018, 01:36 PM
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BlackRocket
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Originally Posted by Jagdpanzer
No problem getting my 94 under 500 NoX with a modified chip that kicked in the EGR at 13 mph. Mods: SW headers, 63mm TB, ported top end, Magnaflow cats, Corsa exhaust. I live in in Northern Virginia which has as tough emission limits as anywhere. Just passed my last test. No more for after 25 years.
That's a better policy is to only look back 25 years. Cali has a bill floating around to move the exemption from Pre 1976 vehicles to pre 1981. However, strings attached; Your 1976-1980 vehicle must still get a smog check and if it fails as second time after mechanical work performed...all one has to do be garnered exemption status is "Pay a Toll to CA of $200"!!!!

By the way; I love the patch in your Avitar!

Last edited by BlackRocket; 01-27-2018 at 01:37 PM.
Old 01-27-2018, 07:16 PM
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mike100
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You are only going to make around 410-420 crank hp best case with factory manifolds (on the early cars). Even if you port the manifold, you need to couple that with a good set of headers to get the 450+ hp these cars are capable of with the chip/pipes/porting bolt-on low-hanging-fruit type of mods.

Anything beyond 450-500 hp starts to get expensive, but at least the car is satisfying uncorked and on stock cams. If you live in an unenhanced zip code where you can avoid the biannual smog check hassle, then go for the headers and the supporting chip for them. I'm not sure I would own a stock zr-1 after having run modified. You want to be able to pull on stock LS6's.

Last edited by mike100; 01-27-2018 at 07:18 PM.
Old 01-27-2018, 07:26 PM
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Originally Posted by BlackRocket
It seems that with the NOX levels lowered in Cali...the LT5's are barely squeaking by.

Can anyone that is familiar; list the mods that will allow better performance while still passing CA smog?

I would assume intake and head porting would not affect the emissions?
Nope

I have heard from others that Haibeck can burn a smog check chip as well as a performance chip. The stock chip works really well. I made a chip with a small reduction in ignition timing and it barely lowered the NOx. it still lowered it, but compression and coolant temp affect NOx far more

Shorty headers with pre-cats? Does anyone make LT5 shorty's?
No..the factory ones are as good as it gets.

Obviously cams would be out of the picture.

What about larger displacement?
you are going to be dealing with 12:1 compression and that's gonna be tough to get good numbers on the smog check

Lastly, 4.10 gears and an aluminum flywheel should have no factor.
It would help imo as the engine will be under a bit less load on the dyno rollers and the test rpm in 2nd gear would be at a higher rpm. This would lower NOx.

Thanks!
B-R
Old 01-27-2018, 10:07 PM
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cruban
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Yup, but good old CA has to pass a visual as well. If they see headers, your done and off to the smog ref. Laws in CA are so screwed up, you could do a new LS3 swap, be perfectly fine on smog and still fail because you can't swap motors anymore without the trans, computer and gas tank (gas tank, really). Thus, it has nothing to do with emissions and all about taking your money.

Originally Posted by Jagdpanzer
No problem getting my 94 under 500 NoX with a modified chip that kicked in the EGR at 13 mph. Mods: SW headers, 63mm TB, ported top end, Magnaflow cats, Corsa exhaust. I live in in Northern Virginia which has as tough emission limits as anywhere. Just passed my last test. No more for after 25 years.
Old 01-28-2018, 03:15 PM
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BlackRocket
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I have heard and read that BG 44 will help a cars emissions? Also, if there are any gasket leaks can't that be determined with a can of starting fluid?

https://www.bgprod.com/catalog/gasol...ystem-cleaner/
Old 01-28-2018, 04:34 PM
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early cars cant have headers. What will happen is youll have to see the smog ref, they will find a stock one somewhere on the national parts locator even if it takes them weeks, youll have to buy and install it. $$$ Telling ya from experience. This state is fd with smog.

I dont see why, if someone had LTs/smog rails and cats they couldnt get a pass what comes out of the pipe is the same?? Course nothing round here makes sense.

Last edited by cv67; 01-28-2018 at 04:35 PM.
Old 01-31-2018, 12:33 PM
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Originally Posted by BlackRocket
It seems that with the NOX levels lowered in Cali...the LT5's are barely squeaking by.

Can anyone that is familiar; list the mods that will allow better performance while still passing CA smog?


Thanks!
B-R
MOVE off the Left Coast. I'm not being an AZZHAT. Its CARB and they have been lowering the allowable limitations on NoX which are programmed to continually be lowered already up until 2025/ 2030.

Cars in the past that used to breeze by or be pretty close cannot/will not meet the newer and future standards. They need to allow a collectable car waiver and move on. CARB WONT.... allow that

Otherwise sell the car or move. CA the land of fruits and Nuts.

How far does CARB go??? Watch Dirty Money on Netflix about the VW Clean Diesel Scandal.

Last edited by Goldcylon; 02-16-2018 at 09:21 AM.
Old 01-31-2018, 02:21 PM
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cv67
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Sold my 97 van, and C4s in part due to this. Used to pass by a landslide, then barely made it. Went back to carb'ed stuff less hassle BUT with property seizure laws its a risk driving those if the smogs missing too.
PD wouldnt worry about too much but CHP.. area Im looking at has no smog even on newer cars .So its hot big deal.
Old 01-31-2018, 03:58 PM
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zrc3john
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Originally Posted by Goldcylon
MOVE off the Left Coast. I'm not being an AZZHAT. Its CARB and they have been lowering the allowable limitations on NoX which are programmed to continually be lowered already up until 2025/ 2023.

Cars in the past that used to breeze by or be pretty close cannot/will not meet the newer and future standards. They need to allow a collectable car waiver and move on. CARB WONT....

Otherwise sell the car and move. CA the land of fruits and Nuts.

How far does CARB go??? Watch Dirty Money on Netflix about the WV Clean Diesel Scandal.
LOL.....I can't believe what you guys on the west coast go through.....Its like, why even own a performance car if they make it so difficult to pass inspection....Last week I got my 91Z I expected up in NY......Its just a safety inspection.....10 bucks,look at the car-yeah looks good, hears your sticker...

Sell the Z,buy a nice 5 series BMW and call it a day....Either that or make friends with a cop or maybe you have a family member on the job who can give you a PBA card.......Leave it in the window if you off street park the Z and mod the crap out of it.......Either way good luck.....Must be frustrating..
Old 01-31-2018, 10:30 PM
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The only good thing in Kalifornia is the weather... between fires and earthquakes of course. Politically if you are anywhere right of center you are not welcome or represented.
H
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Old 02-01-2018, 05:07 AM
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Z51JEFF
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Another problem with smog stations the guys doing the smog test are so paranoid about loosing their license they try too hard at times to smog the car and it will fail. After my car failed twice I took it to a referee station and the guy didn’t do half the crap the first 2 guys did.

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Old 02-06-2018, 06:47 AM
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Paul Workman
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Originally Posted by mike100
I'm not sure I would own a stock zr-1 after having run modified. You want to be able to pull on stock LS6's.


Yup! Add to it stock LS2s and 3s! It truly makes a C4 Z a "wolf in sheep's clothing".

Mercury Marine? Another route one could possibly take to big power yet meet emissions...

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Last edited by Paul Workman; 02-06-2018 at 07:32 AM.
Old 02-06-2018, 08:37 PM
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Old 02-10-2018, 12:32 PM
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How far does CARB go??? Watch Dirty Money on Netflix about the WV Clean Diesel Scandal.
Saw it the other night, interesting

zrc john they want all old cars off the road period. Someone has to pay for the bailout and buy these new.

I wouldnt do anything other than a catback and would do a smog pretest before it was even bought. Having to keep one stock is a big turn off...on porting if youre moving more air you need more fuel. Could Haibeck help out, maybe but thats a lot of work and money for a what if.

The old po box thing doesnt work anymore, has to be smogged within x miles of your primary residence. Hard to own a car you have to hold your breath on to get tags


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