What should I be looking for regarding lambda (at WOT) for my supercharged 5.0 running on pump gas 93 (e10. My understanding e10 can have as little as 2 percent ethanol)

What multiplier do most tuners use to determine AFR on e10?

I need to know enough to review my own logs rather than having to depend on a tuner to always be available. I'm sure he's covered up with logs.

We're getting close to having the revised tune complete for the fuel system upgrade. The weather is preventing from finishing it up right now..

 

You don't use multipliers. Lambda is lambda. 1.0 lambda on e85 is 1.0 lambda on e10 gasoline

The difference is on e85 that's 9.6:1 afr and on e10 it's 14.06

Always read your datalogs in lambda, with a supercharger you should be tuned anywhere from .75 to .79 lambda.

 

.78 lambda is a very safe number either way 93 or e85. might see some a hair higher for more hp

 

Best I understand is that stoich is now looked at as 14.08 compared to the more traditional 14.7 to compensate for up to e10. As stated .78ish is a safe number to shoot for. The EQ ratio would be 1.28 or 1/1.28 = .78 lambda

 

no i get it, it's just that afr is a little more what i'm used to thinking about

Anyway the newest revision stays around .79.

What do i need to look at besides measured AFR (lambda)? lambse, short term and long term fuel trims, and what numbers mean what and when?

 

Stft and ltft are a measure of how well the VE is dialed in. Usually om factory threshold is +/-10 but tuned I like to see +/-5 and really dialed in is +/-2

Say its commanding xx amount of fuel at commanded lambda your trims show what the computer is trimming to meet that target.... +stft means its leaner and adding that xx% to meet. And -stft means its rich and pull that indicated %

Usually when u run outta fuel it shows in the fuel psi and usually the fuel trims start climbing high when the computer is asking for more.

Might be a little off and corrected on it a little but that's the gist

 

thank you