It was the tires/wheels setup. I am running 33's on 15's. The smog dyno can't compensate for that setup. So we put on stock sized tires/wheels and she pass with flying colors. So what do you think of that? Pass the word around. Thanks and good luck.
I will remember that, thanks for the update!
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's
I think the load is out of whack. Spinning a stock tire on a roller is way different than spinning a 33 on the roller. Add mud or AT treads and the load rises again.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's"L.W.(ßill) Hughes III" wrote:
NO. As explained to me, @25mph on their dyno they look at wheel speed not mph or rpm. My tires is 33", sotck is less, they reference off stock. With larger tires you have lower rev's at low rev's engine run lean puts out more pollutants. Increase the rev less pollutants. Therefore smaller tires higher rev's less pollutants. My gearing is only 4.10
Here in Canada, they go by rpm and use rollers, not a loaded dyno. A dyno is for testing HP, the emissions maching is just rollers.
I figure the larger tire is creating more load than your engine can take and stay clean. That implies a tired engine to me.
On the last smog I passed with my 33" muds on and I have 3.31 gears. I got 15 ppm HC and 0.16 CO.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's"B>
It was the tires/wheels setup. I am running 33's on 15's. The smog dyno can't compensate for that setup. So we put on stock sized tires/wheels and she pass with flying colors. So what do you think of that? Pass the word around. Thanks and good luck.
It makes me so glad to live in a state without any test.. yet.
When I lived in the Southwest I resorted to bribery.
Bill, your Bronco also has an EGR valve to compensate for those high combustion temps, whereas the Jeep is just allowed to run on the ragged edge by design. This explains why you pass, and he fails.
Jerry
LOL Should have put it in lo range for them.
--James
If they're testing for NOx, it has to be loaded.
Alas, stock is not 4.10 either! So with the 33's and the 4.10 you are running right about the right engine RPM for 31.4's, which is only 90% of 30's. If they let you put stock tires on, while keeping the non-stock 4.10, it seems like you've found a way to pass these tests even for engines that should fail it!
alan
You know some days I am slower than others.
I just clued into the fact that the computer measures the roller speeds, not the engine speeds...
Wow, that really cam make a difference in say a stock P215 and my freaking 33's!
On mine there is a fast radical change in gas mileage vs rpm, so emissions would be the same. My gas mileage sucks at low rpm.
Hmm, good to keep in mind.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT'sMotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.