04Denali

I know this has been asked before and I keep getting differant answers.
My A/F ratio is 11.3 to 1 at WOT from 0 to 100 mph. I am reading it with a scanner. Have a wideband but it is not hooked up yet. What is the best and safest A/F ratio for a Radix 6.0. Also I might as well ask this now. When I do the 90mm TB conversion will my A/F ratio change?
Thanks
Mark

parish8

iTrader: (6)

a scan tools reported a/f ratio doesn't mean anything. you can look at the stock 02's and knock sensor and get some idea of how you are doing but a wideband is the way to go for sure.

11.5-12.0 is a good range for most boosted set up's. maybe 11.0-11.5 for anyone really pushing it hard. the 90mm tb will likely affect the a/f ratio.

04Denali

Thanks

thunder550

iTrader: (70)

I'll expand on his original question and ask....

Is 11.5-12.0 good only for WOT boost? What about part throttle boost? Reason I ask is that I just got my wideband hooked up, and the only time I see richer than 14.7 is at WOT. Is part throttle boost ok at 14.7?

TurboBerserker

iTrader: (1)

I generally take it to 11.5 anytime I see more than 100kpa (or when I cross from vacuum to positive boost). I used to turn on PE at 40% tps to cover any serious, pre-wot boost. Your enemy is still detonation.

dewmanshu

iTrader: (4)

yeh but what are you calling WOT? What does your pe enable table say? If you are going WOT at 50% TPS, yeh you most likely are safe(disclaimer:everybodies setups have different needs) but if you aren't going WOT until 90%TPS then yeh...14.7 is not a good thing at 70% TPS. IMO. Maybe if your truck weighed 2500lbs.

dewmanshu

iTrader: (4)

turboberserker beat me to the post...or just as he says!

thunder550

iTrader: (70)

I think I mis-represented the question.

What I am wondering is should I be at 11.5-12.0 AFR any time I am into boost? I have a 2-bar MAP on the way and will be loading a custom O/S via EFI Live here pretty shortly, and will be doing SD tuning instead of MAF, so I want to figure out what the best AFR is for the different vac/boost readings.

parish8

iTrader: (6)

i shoot for about 15.5-1 anytime i am not under boost. then as i cross 100kpa(0psi) be around 14.7 and by the time i am at 5psi be about 11.5.

TurboGibbs

iTrader: (6)

With my 1 bar tuning on my 4.8 and 3.0 pulley we custom tuned the rpm. I was sooting up my bumper and killing my mileage everytime it would tip into boost while cruising up and down hills etc. Someone with a 6.0 with more low end grunt might not have this problem. Basically fine tuned the PE table to around 12.5-12.8:1 while accelerating at low rpm that I was seeing while cruising around 2000-2800 rpm. Above that the afr was in the 11.5 range.