AEM A/F gauge

[mtnaddict]

Hey guys everyone says run these turbo cats at 12.0 to 12.5 max at wide open. Well my question is what is for sure too lean? Last weekend I ran mine at 13.0 i think I may remember even 13.4 once but it ran great and my plugs looked good to me. I am courious if there is some variation in these gauges or am I just lucky to not stick the motor? Thanks for any help!

 

[venom]

i've seen 13 lots at wot, 12.7 is the magic # for my setup, runs perfect there. i gotta see at least 12.5 for the sled to run good at all.2 seasons with 0 issues

 

[mtnaddict]

K venom thanks! I just wonder why do they tell you to run 14.5 at low rpm maybe 14 in mid range then only 12 at full boost. What is the difference why 14s are good except for on boost ? It just dont make sense to me?

 

[mynewuseddoo]

14.7 means that the fuel air mixture has burned completely and balanced. Anything lower means you are running richer than equilibrium and thus running cooler and safe. Anything higher and you are lean and we all know what happens there. Now depending on your elevation, fuel, etc, your egt's will be different at different AFR readings. Generaly, the leaner the hotter. Thus, if you're not running EGT's then the high 11's and low 12's are a good all around safe number to play with. Why at WOT? Because it is when your engine is working the hardest and building the most heat which does accumulate and build up over the duration of WOT.