CA smog/hot cam
Thread Starter
7th Gear
Joined: Jun 2002
Posts: 7
Likes: 0
From: olivehurst ca
CA smog/hot cam
this is for you CA guys. Are you getting the HOT cam to pass smog? Ive got my engine in the machine shop right now and am in search of just a little more power, no race car. ( 96' CE LT4 ZF ) . Was planning on same 10.8 comp aqnd a hot cam. the heads have been cnc ported by Chapman racing and are ready to go but i need some cam ( that will cleanly pass emissions ) to match the flow #'s. WIll the stock comp handle the HOT cam? thanks. :cool:
Le Mans Master
Joined: Mar 2001
Posts: 9,464
Likes: 1
From: Modesto CA
Re: CA smog/hot cam (cnc LT4)
Yes, with your LT4, the hotcam should pass smog no problems. Since you're in California, you'll have to go with the Hooker Shorty headers. (Not too bad actually) With that cam and the ported heads and headers, you should also consider throwing on a 52mm Throttle Body. Also, if you haven't done so already, put a set of 4.10 gears in your car. With that combo, your car should run like a raped ape! :cheers:
Drifting
Joined: Jun 1999
Posts: 1,874
Likes: 1
From: Garden Grove CA
Re: CA smog/hot cam (cnc LT4)
Just passed smog, here are my #'s, and this was on the smog dyno:
15 mph: 8PPM HC, .01 CO%, 34PPM NO
25 mph: 6PPM HC, .00 CO%, 85PPM NO
These numbers are far below allowable limits, your results may vary
Some people pass, some fail - it is more than a question of HotCam or no HotCam. If your mods do not compliment each other expect problems on smog. No matter how much people would like to take a cookie cutter approach to engine building, each engine will still run differently. I suggest you run a pre-test just to check it out before you do the big test. Barring any sort of mechanical issues (bad/old sensors, or air leaking into exhaust ahead of O2 sensors), if your engine runs dirty then you WILL have to get programming help to sort things out. Actually what you will need to do is have an additional bung welded in ahead of your cat (either one) and plug in a wide band air/fuel sensor to accurately check for lean or rich running of the engine, and then reprogram accordingly.
Thomas
15 mph: 8PPM HC, .01 CO%, 34PPM NO
25 mph: 6PPM HC, .00 CO%, 85PPM NO
These numbers are far below allowable limits, your results may vary
Some people pass, some fail - it is more than a question of HotCam or no HotCam. If your mods do not compliment each other expect problems on smog. No matter how much people would like to take a cookie cutter approach to engine building, each engine will still run differently. I suggest you run a pre-test just to check it out before you do the big test. Barring any sort of mechanical issues (bad/old sensors, or air leaking into exhaust ahead of O2 sensors), if your engine runs dirty then you WILL have to get programming help to sort things out. Actually what you will need to do is have an additional bung welded in ahead of your cat (either one) and plug in a wide band air/fuel sensor to accurately check for lean or rich running of the engine, and then reprogram accordingly.
Thomas
Melting Slicks
Joined: Jan 2000
Posts: 3,418
Likes: 1
From: NW Chicago Suburbs
Re: CA smog/hot cam (cnc LT4)
this is for you CA guys.
Are you getting the HOT cam to pass smog?
Eric
