Comp cam on factory tune?
Another thing is you'll need good catalytic converters and you need to make sure they are HOTTTTT before they run the smog test. The hotter the converter the more it cleans up HC's. So run the car for a while, maybe even hard, then pull up to the smog station and do not turn it off. Let it stay running to keep heat in the cats. Ask them to rev it a bit before running it (if they seem cool) to help build heat in the converters.
If your NOx is too high when you test, try a cooler thermostat, that will reduce NOx
If your NOx is too high when you test, try a cooler thermostat, that will reduce NOx
TECH Fanatic
Joined: May 2016
Posts: 1,292
Likes: 436
From: St. Louis
I didn't read any further than this post before responding, Bring me the car, I'll put factory ls6 valvesprings in it that will never have to be changed and a milder aftermarket camshaft designed for those springs that will really showcase your milled and ported ls6 heads, it will cost you about $500 in parts your drivability durability reliability everything will be improved and it takes me just an afternoon to do it in my driveway with my kids and wife yelling at me even, but it sounds like you don't have much experience with theses things yet, the 228 is just good for sound it adds a lot of mid range and top end but it's too rowdy imo for a daily that has to idle for longer periods without swilling fuel and yet it is still not big enough to complete with the really big cams other guys run for weekend warrior stuff. put a shorter duration cam in it, learn something about engines and enjoy a lot more useful torque at lower RPMs better fuel mileage and don't look back. just way too many of these cars out there that aren't getting driven because they're overcammed with medium aggressive valvetiming, it's ridiculous Ls engines are just like Legos don't be a baby just change the camshaft now to get by and then change the springs down the road when you feel like it needs it aftera while because the stiffer aftermarket stuff doesn't last as long and it's harder on the rest of the valvetrain parts
Looks like I'm gonna have to drop some real money, and essentially ruin the car to make it pass CA smog long term. If anyone's interested in buying it, it's for sale. Only 36k miles on the clock.
TECH Senior Member
Joined: Jun 2016
Posts: 22,293
Likes: 3,617
From: Central Cal.
A milder cam, stock manifolds, and cats will hardly "ruin" the car.
They don't, and it absolutely will fail visual. To my knowledge the cats can't be touched at all- you can't even relocate factory cats if we're playing by all the rules.
But that's more easily addressed than a cam swap. If I can bypass the tune issue, I'll feel like the car can likely exist in this state and not end up on barn finds one day.
But that's more easily addressed than a cam swap. If I can bypass the tune issue, I'll feel like the car can likely exist in this state and not end up on barn finds one day.
