Ethanol Sensor with M1

Andre,

I've been reading your speedhunters articles and noticed that you've got an ethanol sensor wired in and working with your M150 on the 86.

I've been going through the packages I have available to me and can't for the life of me find anything related to adding in an ethanol sensor. Is this a worksheet you've built yourself or one in a future package for the M1 not yet available to the public?

How does the M1 handle the variable Ethanol content as far as the tune goes? At the moment I had half done a work around using the A and B maps for fueling/ignition with a 98 map on A and a super conservative E85 map on B. Then I'm using the rotary switch to swap between them. However without the ECU knowing the precise ethanol content and able to scale the stoichiometric ratio and pull ignition as it drops off I'm obviously not getting the most out of the E85 so stay predominantly on 98 at the moment.

I'm in the process of upgrading my fueling system on the car and am adding in an ethanol sensor to the new fuel lines for the future. But if these features are available now or not far off that would be fantastic to know. Also if you have the calibration file for the continental sensor on hand that would save me having to build one.

Thanks so much for all your help and insight!

I think I managed to confuse a lot of people with that article and I believe MoTeC got swamped with phone calls after it went live. Unfortunately right now there is no flex fuel support in the M1. We have a development licence for our own ECU, and the flex fuel strategy is one I wrote myself. I have no doubt it will come but it's not on the horizon right now.

Sadly there is no effective work around for flex fuel either. You really need to be able to manipulate the fuel characteristics relative to ethanol content to do the job properly,

Well that's just teasing :-p On the plus side it is promising that it has been done already. I think it's a little beyond me to write my own flex fuel worksheets at this point. I think I could probably write a page to link the AFR to an ethanol sensor output. However I'll need to spend some time thinking about how to link ignition scaling and boost control to the E%. Might have to get you over to WA to work your magic for me :-p

Can I ask a really stupid question? Feel free to decline to answer if I'm infringing on proprietary information. Just I'm new to changing fuels as there's only 3 E85 fuel pumps in our state and I'm still trying to get my head around flex fueling. I haven't even tested the car on it yet as I'm waiting for a station closer to the house/office. Will the main VE table of a M150 be affected by the change in Ethanol content? Your AFR ratio changes based on your E% which affects the amount of fuel required. But if the ECU has the E% from the sensor and constantly updates the AFR will the M150 do the recalcs for required fuel volume on the fly and still hit the target lambda ratios? Or will the added ethanol cooling affect the VE map itself?

With the M1 ECU, in theory you should only need to alter the fuel characteristics to suit whatever blend of ethanol you're running. In reality this doesn't do all of the work though and you will likely need to make some small changes to the VE table as well. Typically these changes should be minor though - Perhaps 2-3% if everything else is working correctly.

So why the change in VE? Three reasons:

1. Injectors actually flow a different fuel volume on E85 than on petrol. To account for this you would need to alter your injector data based on E%.

2. The cooling effect of the ethanol can show a very small improvement in VE simply because a cooler intake charge is denser and hence takes up less volume.

3. The M1 fuel model is still a generic model that needs to work adequately on a huge range of engines. On this basis there are always going to be small inaccuracies in the model.