A/F Question

[kcsvt94l]

Measured AFR and that is the correct(what the ford ecu uses)stoichmetric

 

[Shaun@AED]

Yes, Measured AF is measured lambda.
Lambse is commanded lambda.

The difference between these 2 results in Short and Long term fuel trimming.

 

[mhyjek]

For Reference Ford Racing Procals command .86 lambda at WOT.

.85 Lambda commanded @ 14.64 = 12.44:1 air fuel
.85 Lambda commanded @ 14.08 = 11.97 (Track pack car would read this on the dash)

Same actual air to fuel ratio (lambda), different programming. This is why we use lambda.



Some do run more fuel on the #8, but I do not. We solved the lean condition differently, at the source.

Even more of a reason to have you tune the car!
Can't wait to see what you do with new 2.3 turbo mustang; I'm sure it will be great!
Happy New Year!

 

[kcsvt94l]

Even more of a reason to have you tune the car!
Can't wait to see what you do with new 2.3 turbo mustang; I'm sure it will be great!
Happy New Year!

Shaun is a genius no doubt. I'm going to be calling him soon in fact as I'm going to the Cobra Jet/E85 setup. :beer:

 

[onspeed]

Dyno readings are not accurate enough IMO. They are not programmed the same as the Factory ECU.

Dyno widebands 1.0 Lambda = 14.64:1
Factory Ford Programming 1.0 Lambda = 14.08:1

This means a dyno will always read leaner than the Ford ECU. Couple that with cats and taking measurements at the tail pipe and you could be WAY off on your dyno readings. Especially if the dyno unit is not an ECM wideband.

I tune on Lambda. .83 to .84 lambda commanded on NA Coyotes and into the .7's for boost.

Just to clarify, Ford is commanding ~14.1 AFR as Lamda = 1 for 100% gasoline? So the factory tune is a tad on the rich side?

Also, since they're using WBO2s, there shouldn't be a need for an external WBO2 sensor for taking afr measurements, yes?

 

[Shaun@AED]

Just to clarify, Ford is commanding ~14.1 AFR as Lamda = 1 for 100% gasoline? So the factory tune is a tad on the rich side?

Also, since they're using WBO2s, there shouldn't be a need for an external WBO2 sensor for taking afr measurements, yes?

Yessir

 

[DIB5.0]

A lot of tuners were claiming 30hp gain with tune when they first came out because of high afr and high timing and then messing with the knock sensors. Now most know not to go over .85 lambda and timing no higher than 27* on 93. i think most are at .83 with timing set at 24*.

 

[spdracr0]

So that explains why mine had yet to go nuclear. Not as lean as I thought it was. Well almost.

 

[Shaun@AED]

So that explains why mine had yet to go nuclear. Not as lean as I thought it was. Well almost.

E85 is a wonderful thing.

 

[spdracr0]

And that too.