tt383lt1

iTrader: (3)

im running normal gas right now but im soon switching to e85. will my aem wideband gauges work for e85. the reason for asking is you need to tune e85 lower than 10 afr reading thats on the gauge?

joecar

Your wideband gauge assumes the stoich AFR is 14.7 rather than 9.78; this will give you an incorrect AFR; to correct it you have to multiply it by (9.78/14.7).

The other problem is that the PCM has a parameter for stoich AFR; for gasoline it is set to 14.63; if you don't change it to 9.78 then the PCM will under-calculate the required fuel; in Closed Loop, trimming will correct this, but in OL/WOT you will have insufficient fuel.

Also, since you now need more fuel, you have to check how high your injector duty cycle goes to see if the injectors are able to provide the required fuel.

SERB Z06

iTrader: (6)

^

DO NOT listen to this guy, he has no clue how a wideband works.

A wideband is ALWAYS reading lambda. If you have it set up for gasoline, whenever lambda is 1.0 it will display 14.7. This has nothing to do with what fuel you are actually running.

If you want to do it the right way I suggest adjusting your gauge to display lambda as well, that way there is never any confusion.

NicD

iTrader: (7)

Yup, x2... although I just leave it in gas mode for E85 and read it like normal since the lambda values translate pretty evenly for gas and E85.

2000RATA

I gotta hijack here. So what aftermarket wideband gauge can I install (like in an a-pillar pod) that will be correct for E85? I don't want it to tune by but just keep an eye on things. Plus I need something to fill the third pod.

NicD

iTrader: (7)

Any of them will

2000RATA

Thanks

MarkoLBR

Joecar , you are absolutely right.
Not sure if stock PCM will correct 50% difference regarding AFR.
I´m running an NGK AFX on an custom 3 bar operating system 2002 camaro , HP tuners.
The only way to get a correct reading regarding to lambda is to do what you describe.

Regards Marko

joecar

Marko, thanks

joecar

You will have to set the gauge to display in Lambda as SERB said above (so at WOT you want to see 0.86).

For tuning you will be using Lambda from either the programmable analog output, or the serial comms output if you have EFILive V2.

NicD

iTrader: (7)

Yikes, I give up. Stop mixing up the difference between that setting in HP Tuners and the wideband and stop saying that a wideband reads in afr when all it does is read in lambda and convert based on the fuel type which allows you to read E85 just fine with the gas setting.

To the op, you had better do some more searching in regards to this because I am not going to argue with people on the internet about what is right and wrong.

67RSCamaroVette

iTrader: (63)

If you knew what joecar's experience entailed, you'd take that back in a minute. If you re-read what he wrote, you'd realize that he's absolutely correct.

I tune my car (efiliveV2) on e85 without doing the conversion. The vehicle doesn't know that it's not gasoline, it just knows that it uses an obscene amount of fuel Commanded 14.7 is actually 9.8. Makes it easy, you just have to be careful when putting data in.

NicD

iTrader: (7)

Oh jeez here come the swingers. You need to take a step back and realize that what he wrote is incorrect in how a wideband works, what he wrote about the PCM is correct but irrelevant to the OPs question. Educate yourself then delete your post.

joecar

Ok, here's a quote of my post, show me what I said wrong, I'm willing to learn...

joecar

What do you mean "lambda values translate pretty evenly for gas and E85"...? They are the same (but they represent different AFR's... and no, I'm not saying the wideband reports AFR).

NicD

iTrader: (7)

Your wideband doesn't assume anything as all of them read in lambda and convert to the numerical AFR based on what you set it for and it doesn't care what type of fuel it is.


Meaning that since the lambda values for both E85 and gas are damn close to what you would be targeting that just leaving it in gas mode and going off the gas AFR is just fine. I say this because not all widebands can be set for fuel type and for some people doing the math converting back and forth is confusing so it's easier for newer people to just leave it as is and tune like normal with one. In addition most people and postings online that are talking about what to target are using the gas AFR scale as well for simplicity.

tt383lt1

iTrader: (3)

idk you guys lost me. so i leave it on reg gas. but will it go down to 9.7. so if it reads 14.7 its actully 9.7? sorry im slow at this typ of stuff

joecar

I said "wideband gauge".

NicD

iTrader: (7)

No it won't, just leave it on the gas scale and target AFRs like it were on gas meaning low 11s in boost, 14.7 cruise/idle. Of course your target AFR will vary with your combo, etc but that's a safe place to start. As for your PCM tune settings you can either cut your injector flow rate by ~30% or set the fuel stoich value to the E85 value of 9.8, it accomplishes the same thing just changes what the commanded value is in the scanner.

joecar

Yes, sure, that's fine, the OP could just read the gauge as if he was running gasoline... while his tuning would be based on Lambda or the E85 AFR... if the OP is fine with that.