Passed the CA smog check with LT4 HOT cam
 

My car passed the smog check on the first try here in SoCal, and you know we have the tougher IM240 roller test.
I have a 350 engine, L98 Corvette heads, LT4 HOT cam (1.52 roller rockers), TPIS intake/runners, SLP 1 3/4" headers with Corvette EGR, and dual Car Sound catalytic converters.
MAX is the highest number allowed, AVE is the average of all the cars who test, and MEAS is my values.
Here are the numbers:

15 MPH:
RPM: 1920
CO2%: 12.9, O2%: 2.8
HC MAX: 108, HC AVE: 30, HC MEAS: 31
CO% MAX: 0.71, CO% AVE: 0.14, CO% MEAS: 0.10
NO MAX: 918, NO AVE: 206, NO MEAS: 138

25 MPH:
RPM: 2289
CO2%: 13.0, O2%: 2.7
HC MAX: 83, HC AVE: 12, HC MEAS: 23
CO% MAX: 0.58, CO% AVE: 0.07, CO% MEAS: 0.08
NO MAX: 792, NO AVE: 194, NO MEAS: 96

Good job!

All you really need to pass even CA emissions is an engine in good tune and good cats. EGR really helps our cars too.

I am swapping in a Comp XE 274 flat tappet in the spring and we'll see how that works out on MDs test (same as CA).

That's good to know...

I got my 83 to pass out there with a Comp XR264 cam, a set of double-hump heads, and a few other goodies; but I still have the stock carb, intake, air cleaner, and exhaust. Results like Kevin's and mine show that it's not impossible if you use a little care and don't go overboard with your engine mods.

The CA test is not like most others; in addition to the IM240 dyno test (15 mph & 25 mph) they do a complete visual inspection. They have books that list every single emissions device by engine code / VIN, and they give the car a thorough automotive proctology exam to make sure that every gizmo, every wire, and every tube and vacuum line are connected properly and appear to be functional. They even check to make sure that the sensors are the correct ones (the EFE vacuum TVS in my car has a green cap for instance, some other applications have a blue one, and they checked it).

As far as the numbers are concerned, if your CR is less than 9¼:1 or so, EGR has no effect on the numbers in the test. The higher your CR, the greater the tendency to produce NOx emissions which is what EGR is there for, and therefore the more effect it has. It is basically impossible to get one of these cars to pass a sniffer test without a cat, and for some of them, without AIR too. The less cam you have (the HOT cam is pretty mild) the easier it is to pass the HC and CO limits. And, both Kevin's and my dyno #s prove that your motor doesn't have to be wimpy to get through. My 305 puts up better numbers than alot of the modded TPI 350s on this board that wouldn't pass CA emissions.

I don't have to get my car smogged for a couple of years, but since switching over to aluminum heads with no egr crossover I still passed(somehow:D ). I have a feeling I'm going to have to get a vette egr setup later, though.

Did they give you crap about the egr/heads/headers/etc, Kevin?

Awesome. If you can pass in CA then I know I can pass here in MO.

I passed the IM240 test last year. I don't run EGR either. I passed their bogus test with 2 more cylinders than usual and no EGR. I tuned a special chip just for the test but who's to say how much it helped.

Funny thing is, the limits for my van are TWICE that of the IROC. We don't have any visual inspections unless you fail twice and apply for a waiver.

He didnt even ask me about the headers or my mods, but he did give the car a thorough checking over. He asked if we had done anything different to the car recently and I responded that we put on a new cat. I have the sheet from the test 2 years ago and noticed they lowered the numbers for passing the tests. Bastards. :rolleyes:
It didnt matter tho, this engine passed cleaner than the previous engine did! And that one was mild with an LT1 cam!

I took the Camaro through as stock last November, barely passed (same as two years before); drove home, parked it in the garage and drained the radiator to start the mods in the sig. I have 11 months before I have to go through again. I have no doubt that it will be much cleaner now. It looks stock except for the headers, which have a big CARB tag welded on the #1 primary, so that shouldn't cause any problems.

FWIW, I took my '90 Bonneville and '92 Lumina through last Friday. Both have over 140k miles on them, unmodified except for AMSOIL. Both passed on the "fast past" basis (emissions low enough that it didn't require the full test run). Neither have A.I.R., if you can believe that. We've put 40k on the Bonneville in the last two years, it was cleaner this time than last.

Oh, another FWIW. When the dyno test was instituded here about 8 years ago, they deliberately allowed higher emissions than were required of the manufacturers for any given make/year/model. After 4 years, they started tightening the screws - the excuse given was they didn't want to create ill-will towards the system, give people a chance to get used to it, get their cars up to snuff, buy a new car, things like that. My '84 full-size van barely passed 6 and 4 years ago, then they toughened the standards and it simply wouldn't pass 2 years ago (although the readings were almost identical). New cat solved that problem (the factory cat was an empty shell, I found out).

Sweet. I passed with my 383 and an LT4 Hot cam a few months ago when I was back in So. Cal. on the dyno too. Take that tree huggers! :D