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Old Nov 2, 2017 | 09:08 PM
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Emissions

Hi all

I live in az and have an 83 z28. It's got a summit racing engine put in it. Headers that I don't know the brand a 3 inch pipe to. Flowmaster with dual exhaust. If I put a high flow cat on and tune down the carb will I pass emissions? Side note It has the canister it's just not hooked up
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Old Nov 2, 2017 | 10:46 PM
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From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Emissions

Originally Posted by Josh2637
Hi all

I live in az and have an 83 z28. It's got a summit racing engine put in it. Headers that I don't know the brand a 3 inch pipe to. Flowmaster with dual exhaust. If I put a high flow cat on and tune down the carb will I pass emissions? Side note It has the canister it's just not hooked up
That sure narrows down the engine you have lol
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Old Nov 2, 2017 | 10:50 PM
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Re: Emissions

Sorry it's a 350 from summit racing
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Old Nov 2, 2017 | 10:51 PM
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From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Emissions

Originally Posted by Josh2637
Sorry it's a 350 from summit racing
which one
https://www.summitracing.com/search/...ll-block-gen-i

Last edited by Tuned Performance; Nov 2, 2017 at 10:55 PM.
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Old Nov 2, 2017 | 11:10 PM
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Re: Emissions

It's the gm performance 350/290hp
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Old Nov 2, 2017 | 11:11 PM
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Re: Emissions

It's the gm performance 350/290hp longblock
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Old Nov 3, 2017 | 09:05 AM
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From: Phoenix, AZ
Car: 1991 Z28 5spd
Re: Emissions

Passing emissions is a matter of balancing the 3 parameters. HC CO and Nox. It’s not as easy as “tuning down the carburetor”
Don’t expext to pass the first time, or possibly even the first 3 or 4. Each test will point you in a the direction you need to go until you find the balance, because each parameter effects the other. Although Nox is a little bit independent of the others.
You’ll also need to make sure the evap system is tight, because they’ll leak check the system.
You’ll get lots of advice on tricks to try. For xample, I can tell you adding alcohol (I used methanol 8 to 1 mix) and retarding the timing works well.But if you’re in left field overall, this won’t be enough. Take some time to learn about it and you’ll get it figued out. This took me 3 tries to get here with a stock 305 TPI. (AZ emissions)
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Old Nov 3, 2017 | 11:45 AM
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Re: Emissions

Originally Posted by jczoka
Passing emissions is a matter of balancing the 3 parameters. HC CO and Nox. It’s not as easy as “tuning down the carburetor”
Don’t expext to pass the first time, or possibly even the first 3 or 4. Each test will point you in a the direction you need to go until you find the balance, because each parameter effects the other. Although Nox is a little bit independent of the others.
You’ll also need to make sure the evap system is tight, because they’ll leak check the system.
You’ll get lots of advice on tricks to try. For xample, I can tell you adding alcohol (I used methanol 8 to 1 mix) and retarding the timing works well.But if you’re in left field overall, this won’t be enough. Take some time to learn about it and you’ll get it figued out. This took me 3 tries to get here with a stock 305 TPI. (AZ emissions)
copy that
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