vettin_it

Is that what directly causes a cam car to fail emissions?

Demonic85

That has something to do with it, yes. Of course messing with the flow of emissions parts like the EGR, fuel/air ratio (bigger injectors), and exhaust all play a part too.

vettin_it

Yes I know playing with everything else is a factor. Im keeping everything emissions friendly. But im trying to choose a cam that has a bit more than the hot cam. It also has to pass emissions though!

93-383

The overlap issue can be offset by proper tuning. If the car runs to lean the cyl temp reaches the point that NOx are formed. If the car runs to rich unburned hydocarbon will be in the exh. Bolth conditions can cause you to fail emissons testing.

0Paul Ruggeri

It depends on what kind of test you have to pass. The overlap can cause a problem at idle, but should be OK at higher rpm. Where I live in California the test is run on a dyno at 15 and 25 mph, so you can get away with a little bit of a cam. If it sounds to radical in may not pass the "visual" part of the inspection.

Have Fun, Paul

BrianCunningham

There are cams similar to the HotCam that have the CARB #, then you legal.

Lichen

Luckily in Arizona, they don't test at idle. They bring it up to about 2500 rpm. I have a Hotcam and other mods and would never pass at idle, but pass with flying colors under load.

5abivt

Luckily in Ontario we have friends who own shops that have emissions machines

Demonic85

luckily here in Ohio, we dont have emissions testing period so I can put whatever I want on my car

khhammer

They do in Tucson. First test is at idle, then they run it to about 25 mph for a load test, then back to idle.

Digital Disaster

My last Vette was an '92 LT1 with mods including a good-sized cam. The last thing I used to do before emissions testing was raise the idle to 1500 RPM to pass the idle test.
Nobody at the testing station ever mentioned the high idle.

redrose

bunch of things in the emissions bag...do what all the oem's do (even the new ''variable valve timing'' sith) retard your cam 8-10*...there are several timing cover kits available that make cam timing changes possible without major disassembly.

GeosFun

Here in Redding, Ca, the smog stations put the timing at stock position. Smart buggers!

Digital Disaster

When all else fails, two words: "Denatured Alcohol"

Get a gallon at Home Depot, add to around 4 - 5 gallons of gas.

I had to resort to that when Arizona started doing similulated 'road' tests.
Worked like a charm with apparently no side effects, although I've heard that it may not be too healthy for injectors - don't know if that's true or not....

Travis93

Maybe in your part of Ohio, there is testing here but it may go away before much longer.