emission fail
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 876
Likes: 0
From: Evergreen colorado
emission fail
Quick ???
Now this pup failed hydro carb w/2.70 allowed 1.7 everything else just perfect. Now ??? still had a touch of seafoam in it very little AND no way would they do the test in 4 th gear only looked like 1 st. has cam ,heads ,ported intake,ported 90m tb all this set up done with Tony Mamo so not junk and mid 480's rwhp on mustang dyno . Any thoughts, really heard a lot about this 4 th gear deal.
Thanks Guys
Now this pup failed hydro carb w/2.70 allowed 1.7 everything else just perfect. Now ??? still had a touch of seafoam in it very little AND no way would they do the test in 4 th gear only looked like 1 st. has cam ,heads ,ported intake,ported 90m tb all this set up done with Tony Mamo so not junk and mid 480's rwhp on mustang dyno . Any thoughts, really heard a lot about this 4 th gear deal.
Thanks Guys
Race Director
Joined: Aug 2006
Posts: 12,582
Likes: 13
From: Colorado
St. Jude Donor '16 thru '26
If you have your skip shift disabled it really screws them up.
The emissions computer knows what its testing and that your corvette is supposed to go from 1st into 4th, so it only tells them to do 1 upshift.
I had the same problem last year.
You may still have to much cam or mods to pass.
Hope this helps.
The emissions computer knows what its testing and that your corvette is supposed to go from 1st into 4th, so it only tells them to do 1 upshift.
I had the same problem last year.
You may still have to much cam or mods to pass.
Hope this helps.
Drifting
Joined: May 2005
Posts: 1,590
Likes: 1
From: Littleton Colorado
Do you have a lower temp thermostat? Have you lowered the fan turn on temp? I went back to a stock thermostat and some what lowered fan temps and it cut my hydrocarbons by half. I swear it ran better as well, and gained a mpg or two.
Instructor
Joined: Jul 2007
Posts: 176
Likes: 6
From: Golden Colorado
If you are running long tubes with aftermarket hi flow cats, they may not be getting hot enough to light off. This was my problem, and my car is an A4 with comparable setup. Required a retune and factory cats to get it legal. Dragon finally figured it out.
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 876
Likes: 0
From: Evergreen colorado
Have the themo lt. headers and cats starting to get in that range $$$$ so just just show how much and get exemption or just register that puppy some where else, already had to change ride height wheels and tires , changed oil,gas. Going to give it one last shot with cags. I have lot of problem after mods and tune and seeing significant increase mpg accepting the car is that dirty. Also do know that the test was tuff for tester to do in 2 nd gear maintaining correct speed. So will see, cam is not that nuts little overlap put in at 114 ,Tony said it should go in at 112 but could be close on emissions so go with 114. So who knows.
Thanks Guys appreciate it very much
Thanks Guys appreciate it very much
Drifting
Joined: May 2005
Posts: 1,590
Likes: 1
From: Littleton Colorado
Change the thermostat and fans. I have LT with high flow cats, they did not effect it as much as the thermostat. I have a 228/232 lsa 114 cam and ported heads, even with a poor tune I was able to pass the hydro carbons.
I didn't have a problem with the 1st to 4th issue, not sure why as I have it turned off.
I didn't have a problem with the 1st to 4th issue, not sure why as I have it turned off.
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Thread Starter
Burning Brakes
Joined: May 2006
Posts: 876
Likes: 0
From: Evergreen colorado
update
Talk about open pit found dyno sheets,Then found that, repeating I know that test was done with stock injectors. So when they showed up at + 90 % duty cycle @ WOT ,adjusting started . I was told numbers great but 90% be ok just don't drop to lower altitude HUH ! well can't live with that so back at shop they installed bigger injectors can't find exactly what size but larger injector now down to high 50's low 60's great what showed on dyno ? Oh didn't go back tune looks fine. IN parking lot?? HUH? so told Tony I got this back and I quote : " Someone would have had to rescale the injector table or it would be rich as hell!!! " in the parking lot ? No. So now quest goes on. So now the search for correct tuner.
Thanks for letting Vent ,Better word would "B" but don't need to be yelled at.
Dyno
Idle
Thanks for letting Vent ,Better word would "B" but don't need to be yelled at.
Dyno
Idle
Last edited by jarda; Aug 27, 2009 at 04:48 PM.
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 876
Likes: 0
From: Evergreen colorado
Melting Slicks
Joined: Nov 2003
Posts: 2,192
Likes: 120
From: Bennett CO
2015 C5 of the Year Finalist
St. Jude Donor '05-'10
The first time took it to Dragon and they retuned it and brought it back and reinstalled tune. $$$
This last time, I took the old center section, adapted it to fit my headers, put that on and put a little denatured alchol(sp) in the gas tank and passed the E-test.
This last time, I took the old center section, adapted it to fit my headers, put that on and put a little denatured alchol(sp) in the gas tank and passed the E-test.
