quick99ls1

HAS ANY BODY OUT THERE DONE A HEADS AND CAM PACKAGE IN CA AND PASS SMOG. OR DOES IT EVEN AFFECT IT. IF U HAVE PASSED SMOG WHAT HEADS AND CAM PACKAGE DID U HAVE CAUSE I WANT TO GET A SET

slow

iTrader: (7)

heads should not cause smog problems.

The cam you use, might.

ryan.

99 Black Bird T/A

iTrader: (4)

Properly ported heads won't have a problem. A set of poorly ported heads that have a lot of reversion could cause a problem with the sniffer test.

wingsfan4ever

I'd like to get on this one as well. I am also looking to do a head and cam upgrade in the poor state of California. Has anyone got a good recommendation for a head and cam package with good HP/TQ that will squeak by on smog? This is a good question quick99ls1, I need some answers myself. Thanks!

JF WS6

Well, the first thing is that heads will not really affect your smog numbers as the others have said. That being the case get the best stage II heads you can afford, and get a smaller cam like a TR220 or somewhere around there. You might be able to pass with a TR224, but I wouldn't push it in Cali. The other thing is that since you can't relocate your cats and they do a visual inspection, you're stuck with the stock catted Y pipe. Probably the best you can do is a set of shorty headers like JBA's or something. Then look into what other boltons you can do and get away with like a pulley, ported TB, lid, very good flowing catback.... etc.

You should pass ok I'd think with that setup. You'd probably be somewhere around 400RWHP too I'd guess.

pekkaz

What is reversion ? Is it flow variation from cylinder to cylinder due to poor porting ? That would cause different a/f ratios to the cylinders and a lot of trouble for emissions and tuning.

Cal

iTrader: (1)

Another thing is get your cam on a 114 rather than a 112 degree lobe angle and it will be easier to pass. Quite a few California people with the TR224 on 114 LSA have passed, but this is the upper limit unless you resort to some sneaky tricks. There was someone with a TR230 that passed, but not sure how he did that. Oh and the other thing is, get some good PCM tuning and that will help you pass as well. A cam makes the idle go way rich in an LS1 plus you may get some missfire codes.

Cal

iTrader: (1)

No, it's not that. Reversion has to do with intake/exhaust pressure reversals. Can't tell you more than that, but I'm sure there's an expert around that can jump in here.

99 Black Bird T/A

iTrader: (4)

I'm not expert for sure...but as I understand it, reversion is when exhaust gas gets sucked back into the cylinder and dilutes the intake charge. This hurts power and makes for nasty emissions because the charge doesn't burn correctly. Heads can be tested for reversion and there are techniques to reduce/eliminate it. If the .100 flow numbers are very high compared to the typical ported head I'd be a little worried. SRP tested my TEA 5.3's and they checked out fine no problems at all. I think the good porters don't have issues with this sort of thing, it's the hacks that do.

Other factors can play a role too.