One value or average, over a run is not optimized.
Most will see a better time slip if you 60’ with .93 lambda and start pulling fuel on the top end. .82l in the traps. Every combo is different but once optimized for yours from testing, it will repeat. Changes based on weather is chapter 2.
Review of O2 Data in a trend, post run, is the only way to get this perfect.

quote:

Originally posted by markemark:

quote:

Originally posted by NC3x58:
What's everyone's idle O2 readings with methanol?

With MFI my idle was 4.0. With EFI now my target idle AFR is 4.6

WOW, that seems rich!
Joe

quote:

Originally posted by sr4440:

quote:

Originally posted by markemark:

quote:

Originally posted by NC3x58:
What's everyone's idle O2 readings with methanol?

With MFI my idle was 4.0. With EFI now my target idle AFR is 4.6

WOW, that seems rich!
Joe

Kinda what I'm thinking...

quote:

quote:

With MFI my idle was 4.0. With EFI now my target idle AFR is 4.6

WOW, that seems rich!

Kinda what I'm thinking...

I agree, it’s way rich… but here’s why…..

Never had a O2 sensor until last year when I initially installed Holley Dash/ ECU minus EFI and collected data from the MFI system that I ran since 2007 when I purchased the car. This MFI system was on every sbc I owned and on a dyno several times from different builders. 3 months of MFI data acquisition showed 4.0 idle and 5.2 average wot running. The Primer Plus system on 93 octane that I use for warm up and running off track using the methanol scale reads 6.1 average. This O2 sensor from Holley is for methanol, comes from them calibrated for their ECU.

When I switched to EFI after 3 months of data collection, I followed the MFI. The initial idle map I used produced 4.6 -4.8 readings, felt fine and haven’t experimented with as I only have 90 runs on this new to me EFI system that I’m still learning how to use/ tune. EFI is easily manipulated.

My engine idles at 1300 rpm in gear…. my preference.

quote:

Originally posted by NC3x58:
What's everyone's idle O2 readings with methanol? I know gas likes 13.5-14.0 or so, does that equate to about 6.2-6.5 on methanol scale? Just curious.

5.5’s