What % e85 does pcm use alcohol settings?

[joshmith]

I converted my 2006 Silverado to Flex Fuel. Wired in the sensor and turned everything on in the tune. It is reading 75-80% alcohol on the scanner and Commanded Stoich is changing. It is not adding the spark from the Flex Fuel adder table though, this is the main reason I wanted to have it recognize e85, I am boosted and want to take full advantage of the added timing but run either fuel and not worry about reflashing. So it dawned on me one night that there is no where in the tune to select a point to start using the flex settings, if I only have 40% ethanol I would want less of the timing in the adder table then when there is 80%. I hope I am making sense here, Can someone point me in a direction? Anyone else noticed this or have a fix? This is for anyone who has converted a P59 non-flex OS to flex. I suspect that original flex fuel OS's work correctly. I will post the current tune but no logs the motor is out of the truck right now, have not driven it in a few months but the new motor and turbo set up are just about finished and would like to get back on this.

[joshmith]

Bump

[Pulse_GTO]

I have a 2004 GTO and I have all the parts to make the conversion. There is no place in my tune to tell the PCM when to modify timing based on alcohol percentage that I have found yet. Maybe it is a table that we don't have access to as of yet and needs to be made available?

[joshmith]

Thanks Pulse, anyone else have any input?

[joshmith]

Ok,let me ask a different question then. If you have added the sensor and successfully converted to e85 are you seeing any timing being added via the "flex fuel adder" timing table?

[joshmith]

Hello...is this thing on?

[LSxpwrdZ]

Some OS's have a multiplier vs composition table right under the AFR Spark correction tables. Why they got placed there I don't know but that is the table I use to slope the Flex Fuel adder table in based on E%.

[Pulse_GTO]

I've attached two screenshots of the Engine>Spark>Advance area of an 04 GTO and an 08 Silverado.As you can see this table that was mentioned above is not in the GTO or any other P59 OS I could look at.

Is this something that the HP Tuners staff could add?

[Pulse_GTO]

Made a request here. Guess now we just have to wait and see.

[joshmith]

Nice work Pulse, that's exactly what we need...Good looking out!!

[yellz06]

Did this get solved????

[joshmith]

Not Yet

[Road]

I've attached two screenshots of the Engine>Spark>Advance area of an 04 GTO and an 08 Silverado.As you can see this table that was mentioned above is not in the GTO or any other P59 OS I could look at.

Is this something that the HP Tuners staff could add?

Its right there under that red circle you drawled misc flex fuel spark its the multiplier for the spark table? Are you asking for a table to blend spark for different E%?

[yellz06]

exactly.. the blend for different ethanol content