2000-WS6-Formula

i will be having a cam installed next month and i have a quick question? which of these 2 cams will pass smog EASIER with a LS1-edit tuning done--TR224-112 or the GM hot cam. the owner of the shop who will be doing the install and the edit says he will tune it one way then when i am due for smog bring the car in and he will tweak it to pass,then bring it back and he will change it back. when this was discussed we were talking about the hot cam. thanx for any info

wrencher

iTrader: (2)

I would go with the 224.
The long exhaust duration of the hot cam does not help emissions.
I've seen 224's run fair, but the 112 makes it alittle worse.
Does cali have obd emissions?
I know there pycho out there w/mods & emissions, has this shop done others?

Nickn20

I would also go with the 224.

mcflyz28

yea me too

M6HuggerSS

let us know if that 224 112 passes...ive heard its really hard??

2000-WS6-Formula

the guy who owns the shop pretty much only works on LS1s,he owns a 2002 Firehawk,and he seems like he knows what he is talking about. he said he could get me to pass with a little tweaking on the tune on the hotcam.

2000-WS6-Formula

my first smog check since i bought the car will be in 4 months,so i will wait till i pass and then do the cam so i will have atleast a couple of years before i have to tweak the tuning. i think i can re-register the car early so i dont have to wait the 4 months to put the cam in.

BAD XXX

Beware, smog checks now include a OBDII pcm check to see if the program has been altered. So if you return your pcm to stock, you may not pass the test due to high emissions. If you have a "smog tune done", you may fail the OBDII test. The LS6 cam should pass, as long as you lean it out before the test, and drive at least 60 miles to clear the PCM buffer.

Mekkadon

iTrader: (3)

holy chit I hope they don't bring that over here. They have the OBDII scan tool here to scan for codes but NOT check to see if the factory computer has been tampered with.

Nightclaw

This is the main reason I went with the TR224-114. The 114 LSA should pass OK, or so goes the theory anyway. I'm kind of in stealth mode for the next two years though, since I got my car smogged this past September and have 1½ years to go for the next one...

'Till then though:

Big Stick

It's my understanding (not first hand, though) that the OBDII testing can't determine if the PCM has been changed per se, it only checks the readiness state of the on board diagostics test (hence OBD). However, me thinks it could fail you if you've turned off too many of these functions via edit (like rear O2's) and each testing authority would set the pass / fail limit. But I don't think (key word) that it would know if you changed the fuel and spark tables, for example. My research tells me the OBDII testing is nothing to worry about. Anybody want to chime in?

Now my question is what cam characteristic(s) most severely affects emissions? Is it lift? Duration? Overlap (i.e. LSA, ICL)? or all three? If I were to design a cam (turbo app, btw) which of these, if any, would I sacrifice? Would, say, a cam with long duration, medium (.580) lift and wide LSA (no overlap) pass, assuming everything else is stock / in compliance?

BAD XXX

I agree. I don't think that fuel or spark curves will show up in the test. Do not reset the PCM or disconnect the battery before a smog, and if you detune your car for smogging, do it a couple of days before you take it in and put on around 60-100 miles. Most logging software can perform the same OBD test, I think.

2000-WS6-Formula

thanx for the info.

wrencher

iTrader: (2)

All OBD-II emissions systems pull generic info that is common to all '96 & up vehicles.
The readiness tests, the drive cycles, partial failure records etc.