ECU Settings for Flex-Fuel

[mapper]

Hi

Are there some recommendations how to setup the axis for Flexfuel on a turbocharched engine (4G63)? The plan is to run E85 and 98Oktan fuel.
I worked out the follow way; I'm happy for any suggestion or improvment proposal.
Fuel and Ignition:
Setup the Z-Axis for fuel and ignition with Ethanol Content %. I made a own fuel and ignition map for every 10 percent ethanol content.That result in 11 separate ignition and fuel maps! Does the ECU interpolate between the z-axis maps or just switch at the next point that is in the Z-axis setup and change the running map?

I also like to have boost based adjustments on ethanol content. Tried to span the Y-axis of the boost aim table with Eth% and adjust boost. I think the normal wg position should also be corrected. Should I use also Eth% content? Think i would be easier to spann the Y-axis with target boost, so normal position is based on aim boost and rpm.

last thing, is cold start. I would use a compensation table to and add fuel based on engine temperature to enrich based on Eth.%. Are a crank correction also neccessary?

Only thing that i'm worry is that the fuel and ignition map has with enabled Z-axis only 11x16zells. Because we want run over 2.0bar of boost the resultion for MAP is very small. Because of that i tought to make main Tables TPS vs RPM and take the 4D table as a boost compensation table. Recommendet or not?
Thank you for any suggestion!

[Scott@FP]

Use the output of the FF sensor (% Eth) as a simple 2D multiplier in a comp. You don't need Z, its a simple linear compensation. For start/warmup, use an unused aux table with % Eth and coolant temp, then use the calculated result of this 3D table as your normal coolant temp axis in your start/warmup tables.

[mapper]

Thank you for your Input.
What I was told from different peoples, the ratio between E85 and pump fuel isn't linear. The other thing is, that we can only add say 5degree timing overall with E85 in the tank. But if we are already at MBT on pump fuel, we will get to advanced ignition in some regions of the map and on othters will be much more on the table. Thas why I setted the ECU like I mentioned above.

I really like the way, how LINK handles Flexfuel in theire new firmware. There are one fuel map for 0% ethanol content (pump fuel) and one for the other fuel, in this case 85% ethanol content. Then there is a 2D table which is used to modified the interpolation between the two maps, dependant of ethanol content. Same pricipe adds to ignition, boost and cold start table.
is there a way to do it the same way on a M400? That will save some time, because you don't have to deal with 11 different fuel and ignition maps.

[mstech]

The fuelling compensation for E0 - E85 is for all intents linear, however the ignition timing compensation is not, from E0 - E20 there is (typically) very minimal, if any, change in the amount of timing that an engine will take. From E20 - E70 there is a steady increase to the amount of timing that can be taken by the engine, and then from E70 onwards, it tapers off again.

The same sort of compensations apply to boost levels, with the boost compensation curve following the ignition compensation curve.

This of course depends on the engine, and how susceptible it is to knock, as well as how much timing it needs for MBT, if you can achieve MBT without knock on E0 - E20, then the gains that you get, and the shape of your compensation curves will be different to those of an engine that is knock limited on the lower ethanol content fuels.