I have a 89 IROC with a 350 TPI. I am going to completely rebuild the engine and was wondering how far I could go and still pass emissions inspection. I was wonderin if you guys have used the ZZ9 cam and/or vortech heads. any help would be appreciated

 

Ring,

Welcome aboard!

I have no experience with the TPIS ZZ9, but I do understand that there are some fairly heavily modified engines passing emissions testing every day. Several things help get you through the tests, including a good pair of cat converters, high coolant temperature and fully warmed engine, plenty of air injection, and a low combustion temperature.

Ethanol fuel can help keep combustion temps down if you don't use an EGR, but an EGR doesn't cost any real power since it should be fully closed at wide-open throttle. A good air injection trick is to use a manually wired electric A.I.R. pump from an LT1 to dump air to the exhaust during the test. You can install a higher temp thermostat for testing, or unplug or manually kill the primary cooling fan (if you have two fans) to keep temperatures up for testing.

I'm sure there are a lot of other good suggestions, and I'm betting you'll find the best ones right here.

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Later,
Vader
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"No matter how hard you try you can't stop us now"
Adobe Acrobat Reader 4.0

 

I do have one of my fans wired like Vader said and my temp will atay at 200* for emission testing.
Also I have a ZZ9 cam and 6085 Edelbrock heads with 1.5RR with Edelbrock TES headers and a custom dual exhaust with 2 cats and 2 mufflers.
And the best thing is it is PA emission legal!
So that is what I have hope it helps you.

Good Luck!

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89 IROC 350 Auto
Custom DUAL Exhaust
Edelbrock Performer 6085 Aluminum Heads
ZZ9 Cam
TPIS Level 5 Chip
14.01 @ 97.0mph with 2.77's gears and a bad ignition control module!
And Free mods.

 

Thanks guys, iw ill give it a try.

Tim