pcmhacking.net

Hi all,

I am trying to get a bit of a spreadsheet for flex fuel together for my car and I have absolutely no idea where to start?
At the moment I have 2 tunes for my car. One is for Unleaded 98 and the other is for E85 ethanol. I am running $11p.
At the moment if I wish to change fuels I have to completely drain the tank of fuel A and fill it with fuel B then change my tune. I'd like to be able to run true flex fuel but that is currently not possible.

For now what I am trying to setup is monitor my ethanol content with a fuel analyzer, use that measured value in an excel spreadsheet to provide me with a modified commanded fuel and spark table based on that measured value. If I am running E85 I will get 100% of the ethanol commanded tables. If I am running U98 I'd get 100% of the U98 table and if I am running 42.55% ethanol I would get half way between the two tables.

My question here is can anyone please help me with a formula for the spreadsheet to achieve my desired result?
I have attached a spreadsheet of the two fuel tables (please note the values are not my current values) but i have not yet added the spark tables. If I can get help with the basic formula I can copy and paste it to suit.

I hope I am not asking for too much,

Thanks in advance.

Barbs

I have worked it out all good thanks anyway

I have attached the sheet if anyone is interested in using it.

I've neatened it up a little for you.

It'll be interesting to see how well this works. Please do keep us up to date as you progress.

antus wrote:It'll be interesting to see how well this works. Please do keep us up to date as you progress.

I will do mate. hopefully it works perfectly. I just bought a flex fuel sensor and a HZ display on ebay for $70 total.
50Hz is 0% ethanol and 150Hz is 100% ethanol. i have added to the spreadsheet where i simply input the measured frequency and it changes the tables for me.