Thought this might answer some questions on cams passing emissions.

The car:
-1995 Z28, 4L60E w/TCI 3500 stall and 3.42 rear gears.

-Used a Combination Motorsports 227/233 .560/.569 112LSA cam on stock
UN-ported heads. Comp 918's with all the goodies, and comp pro mags.
Double roller timing chain and electric water pump.

-Exhaust consists of MAC mids, factory cat converter (for testing purposes
only ), GMMG cat-back. All EGR and AIR related components still on
vehicle. O2 sensors are close to 4 years old.

-Also this was all done on a mail order tune from Bryan @ PCMforless

The test:
-Ohio emissions test required to be done on the rollers with sniffers in the tail
pipes, because of the year of the vehicle.

The Results:
Emissions ASM:...............Reading...........Units........ ...Limit...........Result
HC................................9.5............. ..PPM..........114.0............Pass
CO...............................0.01............. ..%.............0.63.............Pass
NO...............................342.5............ .PPM..........796.0............Pass
CO2..............................14.65............ ...%................................N/A


And just for reference these results were LOWER than the last time I had it tested without the cam in it. If any one would like to see those results just let me know.

Questions, comments, concerns are welcome. Thanks for reading.

Buddy

 

good info. that stock cat must be the trick, maybe the heads to.

 

OEM cats are VERY good and many a person who could not pass with aftermarket cats found the car can with OEM.

 

i will agree the cat may have helped in this case but heads will have nothing to do with passing,a fully set of ported larger valved heads will make very little difference in hydrocarbons etc.
at any rate good job,how good does your combo.work as far as the track?

 

Don't know, I finished the car at the end of the season last year and since I've brought it back out after the winter the tranny has started to slip on the 2-3 shift. Once this started I've been taking it easy on the car until I get the money for a rebuild or 6 speed swap.

Buddy

 

How do you like the 227/233 cam on the street? I had a 94z a4 with all the bolt ons the 227/233 cam and roller rockers and I hated it. I was really disappointed with it. The previous z I had had the hot cam in it and would run circles around the 227/233 car. Maybe because it was a convertible I don't know. Just wasn't happy with the combo and ended up not liking it so much that I traded it in on a 03 silverado SS. Not putting down your setup just want to know how you liked driving yours.
Brandon

 

I am about ready to buy that cam on a 111 LSA, so I am curious to hear how yo like it. My buddy trapped 113 with his cam only 227/233 car, untouched heads, so I wonder if you do the same.

 

Ohio has emissions? What are the laws, im definently running illeagal.

 

Were are you in Ohio we defiantly do not have any emission laws over here in stark county.

 

Although this is apples and oranges, it would nice to know what the difference
between our testing data means. Here is my emissions data for the 25 mph
test. This is on a dyno with the sniffer. In CA you run on the dyno at two speeds
(15 mph and 25 mph):

Emissions(@25 mph):....Reading...........Units........ ...Limit...........Result
HC..............................29.0.............P PM.............33.0............Pass
CO..............................0.13.............. .%.............0.44............Pass
NO..............................16.0.............P PM............696.0............Pass
CO2.............................14.45............. .%...............................N/A

>>Your Results<<
Emissions ASM:...............Reading...........Units........ ...Limit...........Result
HC................................9.5............. ..PPM..........114.0............Pass
CO...............................0.01............. ..%.............0.63.............Pass
NO...............................342.5............ .PPM..........796.0............Pass
CO2..............................14.65............ ...%................................N/A

Considering the cam differences, it makes me wonder what is going on to have
so much more HC with a baby cam. Maybe it's cat differences. I don't really
know what the differences in the parameters mean but it would be nice if
someone could chime in with some ideas.

 

Brandon94Z28,
I really enjoy the cam. To me it doesn't drive that much different than stock below 3K (don't get me wrong, you know there is a cam in there but I think the high stall helps ALOT with driveability). Above 3K it pulls like crazy all the way to redline.

95fbformula,
I'm in Lake County, 1 of 7 counties in the entire state that require emissions testing.

truedualws6,
Our test are done at one speed 25 mph. The only thing I can attribute the lower emissions to is using the factory cat, although that is the same cat I used last time it was tested. And as stated earlier in the thread, my results this time with the cam are lower than when stock with just headers. I'm not sure what would cause the difference. Any insight from another member would be great.

Buddy