Seeking thoughts on a Generic Target AFR at WOT

[Buggeee]

Just to get the machine running and then play with it from there...

A self-learning EFI quick start widget asks me for basic information about the engine configuration and then the last question is...

What is the target AFR I would like to have at WOT. It's not caring what I think about cruise or idle, it just asks me for my desired AFR at WOT.

I read in another forum that 14.7 could be a reasonable AFR at WOT for an air-cooled? What do you think would be a good middle of the road place to start with as a target AFR at WOT?

Also, as long as I'm here, and because I'm a dumbass, will someone confirm for me if higher AFR numbers are richer, or leaner.

My goal is simply for it to stumble around while I learn about EFI. Not concerned about maximizing power, or maximizing MPG. I will get to the tuner software and toying with it all at some point, and to start out I plan to let it self-tune for a while, and then data log that to see what it did for a map, making changes from there and seeing what is better and what is worse than what it came up with on its own, after a bit. All for fun.

If it matters, I am putting a 2300 Holley Sniper 2v on a stock 1600 DP longblock with pertronix III SVDA distributor / coil / wires. A Holley to Weber adapter plate mates it to an open throated progressive-carb intake and using the preheat tubes. I've got the case closed up, and heads on, and have most of the parts ready to go but waiting on some AN fittings and fuel hose to arrive.

Not looking for a discussion of my misdeeds here, just a ballpark AFR to type into the widget to start the learning process of the ECU when it asks for it.

This is my hobby, while my girl prefers crochet. If I melt an engine, I'll build another one and break that one too until I figure it out. This may be a short lived configuration, or forever, depending on whatever tomorrow brings. For now I'm starting here just for no reason at all but curiosity.

Thank you fellow airheads!

[Buggeee]

Cruising around carb AFR discussions on another forum and found this really cool chart.

Also, I'm reading in those carb discussions that 12.5 AFR at WOT is a good feeling, which does match this chart.

[Buggeee]

https://www.aircooled.net/how-to-use-a- ... -4-engine/

I found that very informative article on John's Aircooled.net tech section. He seems to be suggesting 12.8 to 13.2 AFR at WOT.

Also I've now learned that higher numbers are leaner and lower numbers are richer, so there is progress.

[panel]

I read in another forum that 14.7 could be a reasonable AFR at WOT for an air-cooled

This seems to lean for WOT.

[Buggeee]

Seems so. What I've learned in the interim is that 14.7 is the most efficient burn, chemically, but that in real world application inside the chamber of the engine 12.8 is the number to eventually achieve.

[Clonebug]

I run 12.5-12.0 with the turbo and high boost....... and 14.1-15.5 for light cruise.
Whether it is correct or not I don't know but I've tried most every variable out there.I definitely don't like the real lean cruise of 16.0-17.0 some people use but then I have a turbo so my light cruise is a very small window especially at 3000 rpm or higher.

[Piledriver]

12.1-13:1ish at wot, NA.
12.1ish-11:1 boosted

At cruise, lean burn takes a lot of advance, burn slows way down.

GM, at least found they had to provide extra fuel to keep the plugs from melting (or glowing) during high boost after a few seconds.
They target 11:1 or even richer.
Megasquirt 3 (and IIRC MS2-extra IIRC) has this capability.
(High power-time enrichment under advanced menu)

I used it because aircooled.
Older ACVWs ran ~11:1 afr from the factory at WOT.

[michaellatini]

I was looking for the same last week and, found this article online so, thought it might be helpful.

http://www.masterenginetuner.com/air-fu ... -tips.html

Best of luck.
Michael.