[Dysan911]

When running some E85 can you still use your A/F gauge setup on the gasoline scale or is it better to switch over to a Lambda reading?
If say you're used to seeing the A/F like an 11.8 or 12.0. on pump gas. Would that be thrown off with E85 in the tank and start reading something way different?
If I can wrap my brain around this. I think Lambda and AFR are just two different ways to read the same thing right?
If I had my gauge setup for Lambda a .84 should be the same as a 12.3 on AFR right? It's just whichever reference your used to using?



Thanks guys!.

[KingLT1]

You can set it to read on the gasoline scale.

Lambda should always be 1.

[TJay74]

Originally Posted by KingLT1

You can set it to read on the gasoline scale.

Lambda should always be 1.

Lambda being 1 at what, cruise?

Ted tunes Lambda for .83-.84 at WOT from what I have seen.

[Gunkk]

Why bother trying to calculate stoich ratios in your head depending on what % E you happen to fill up with? AFR is soooo last century. Forget about AFR. Re-train your brain for Lambda. It's easy.

Just remember this: Lambda = 1 is stoich regardless of fuel type.

For NA you want 0.8 to 0.85 Lambda. Any more than 0.85 and it will probably blow up.


Read here starting around post 8...

https://www.camaro6.com/forums/showthread.php?t=484443

Lots more in the FI section.

[KingLT1]

Originally Posted by TJay74

Lambda being 1 at what, cruise?

Ted tunes Lambda for .83-.84 at WOT from what I have seen.

Like Gunk said, Lamda for stoich is 1.

.82-.84 lambda is where these engines like to be WOT with boost when running E.

My point was how Lambda was used. If you just say "what is Lambda", then it's going to be 1 which is Stoich for the type of fuel being used.

The Nice thing about a flex sensor is the ECU calculates % for different amounts of E content so AFR can still be correctly used on a gas scale.

[Juiced1]

Switch it to Lambda. AFR is useless if you're running E85 and you won't get accurate readings.

[KingLT1]

Originally Posted by Juiced1

Switch it to Lambda. AFR is useless if you're running E85 and you won't get accurate readings.

I agree, but If the ECU automatically adjusts the stoich value for the amount of E in the system, then the AFR reading is always correct no?

[Harpinc]

Originally Posted by Juiced1

Switch it to Lambda. AFR is useless if you're running E85 and you won't get accurate readings.

You will get exactly the same reading just not converted to Lambda.

[chaoscentral]

Just stick with Lambda. Especially with a flex fuel capable car. 1 lambda is 1 lambda. You don't need to worry about AFRs and converting. AFR is old school. Lambda is modern. Some gauges like my AEM X-Series Wideband OBD gauge the AFR display is hard coded with a 14.65:1 stoich. So if you use that AFR display with e85 in the tank it'll give you erroneous readings and is recommended to be used in Lambda mode only when using anything other than gasoline.

[zincgt]

I log in lambda but in my cars I have the wideband setup for gas scale, even when on e85. Its just easier for me to quickly glance and register if its good or bad while doing a pull. I use the log to tune the car not my quick glance.

[KingLT1]

Originally Posted by zincgt

I log in lambda but in my cars I have the wideband setup for gas scale, even when on e85. Its just easier for me to quickly glance and register if its good or bad while doing a pull. I use the log to tune the car not my quick glance.

I do the same thing... no issues.

[BlueinTN]

Originally Posted by chaoscentral

Just stick with Lambda. Especially with a flex fuel capable car. 1 lambda is 1 lambda. You don't need to worry about AFRs and converting. AFR is old school. Lambda is modern. Some gauges like my AEM X-Series Wideband OBD gauge the AFR display is hard coded with a 14.65:1 stoich. So if you use that AFR display with e85 in the tank it'll give you erroneous readings and is recommended to be used in Lambda mode only when using anything other than gasoline.

This right here above.



I understand the problem with Lambda...besides its hard to say...the scale doesnt make that much sense. it like inches vs mm. Every machine I work on is Metric but I still convert everything to feet and inches in my head. I just use my caliper to do the work. Same with F and C. 40C doesnt sound hot but 104F does!



best way I think of it is an O2 sensor reads Lambda so what you are seeing gauge wise is a conversion. All fuels the stoichiometric is 1. Gasoline ,oil, diesel, propane etc.

[Harpinc]

Originally Posted by chaoscentral

Just stick with Lambda. Especially with a flex fuel capable car. 1 lambda is 1 lambda. You don't need to worry about AFRs and converting. AFR is old school. Lambda is modern. Some gauges like my AEM X-Series Wideband OBD gauge the AFR display is hard coded with a 14.65:1 stoich. So if you use that AFR display with e85 in the tank it'll give you erroneous readings and is recommended to be used in Lambda mode only when using anything other than gasoline.

What do you think it's measuring?? It's not measuring the fuel and has no idea what is running through the engine.