2G AFR at Idle with 272 Cams?

[Sik95TSI]

I was speaking with someone earlier today and they were telling me since I'm running 272 cams I want my AFR to be a like 13.3-13.5 at idle this correct?? Right now I'm at about 14.5-15.1! Any input would be great thanks guys!

 

[MJBean420]

Im running around 14.5 at idle with DKS 272s.

 

[clipto]

I was speaking with someone earlier today and they were telling me since I'm running 272 cams I want my AFR to be a like 13.3-13.5 at idle this correct?? Right now I'm at about 14.5-15.1! Any input would be great thanks guys!

Your idle is perfectly fine. If you wanna fine tune it with ecmlink or something you can other wise it ok. just check the logs. I idle at the same. my a/f is 14:7-15:3.

 

[Sik95TSI]

Your idle is perfectly fine. If you wanna fine tune it with ecmlink or something you can other wise it ok. just check the logs. I idle at the same. my a/f is 14:7-15:3.

Yeah I figured I was ok I just wanted a second opinion. 13.5 at idle seems kinda rich if you ask me WTF

 

[clipto]

Yeah I figured I was ok I just wanted a second opinion. 13.5 at idle seems kinda rich if you ask me WTF

Yea try aim for a 14:7 at idle, btw what 272's are you running?

 

[Sik95TSI]

Yea try aim for a 14:7 at idle, btw what 272's are you running?

Brian Crower.

 

[jmkoons]

For those with emissions (smog) requirements, dare I ask if you have gotten through with the cams in? I've yet to upgrade that area, but it is on the list and I'd hate to swap back just for that next time. The upgrade in mind is mild - 264/272. My tester has been OK with minor cosmetics, sticking to the obvious visuals (cat in place) and tailpipe numbers.

 

[Sik95TSI]

For those with emissions (smog) requirements, dare I ask if you have gotten through with the cams in? I've yet to upgrade that area, but it is on the list and I'd hate to swap back just for that next time. The upgrade in mind is mild - 264/272. My tester has been OK with minor cosmetics, sticking to the obvious visuals (cat in place) and tailpipe numbers.

I haven't yet. But I know people.

 

[ed1380]

Comp 264/272 and its 14.5-15 at idle. Cams shouldn't affect idle afr. The o2 is supposed to regulate it

 

[jmkoons]

For the static case, yes - same volume of air and burst of fuel. But with larger lift cams the dynamics change and at some point the idle turns edgy since the engine speed is barely enough to maintain smoothness - lumpy, lean miss, etc. Probably not at mild upgrade territory, but it may start to throw off the ability of the car to burn as cleanly as it did with stock lift and valve specs. A Road Race Engineering mechanic told me a number of years back when I asked about this, "Oh, you'll never pass with cams in there." That might be a stretch to say that any cam upgrade will doom passing smog without swapping back, but I had yet to confirm about what kind of numbers folks were able to get with a mild upgrade.

 

[clipto]

For those with emissions (smog) requirements, dare I ask if you have gotten through with the cams in? I've yet to upgrade that area, but it is on the list and I'd hate to swap back just for that next time. The upgrade in mind is mild - 264/272. My tester has been OK with minor cosmetics, sticking to the obvious visuals (cat in place) and tailpipe numbers.

as long the tune still good you should pass, just try and see what happens.