Before reading this setup guide ensure you have read and fully understand all of the following topics (and the topics referenced by them). The guide assumes the reader understands all of the setting and ideas presented!
Setup and Tune for the First Fuel
The first fuel can be either of the fuel types used, but for clarity it is often better to be the primary fuel the engine will run on. Typically in a gasoline/ethanol setup this will be the gasoline.
The first step is to tune the engine as though it was only going to run on the first fuel.
1.Fill the fuel tank with pure unblended first fuel. Go to some effort here to make sure there is no residual mix of fuel.
2.Set the Fuel Equation Mode to Modelled (not Multi-Fuel).
3.Setup all fuel, injector and engine properties for the first fuel.
4.Setup Cold Start adjustments. If using significantly different fuels or petrol/alcohol blends then these steps will be required. These settings are found under Fuel->Cold Start.
1.Set Pre-Crank Prime to use a 3D table. Set the table axis to be ECT and Multi Fuel Blend (or Ethanol % if more appropriate).
2.Set Crank Enrichment to use a 3D table. Set the table axis to be ECT and Multi Fuel Blend (or Ethanol % if more appropriate).
3.Set Post Start Enrichment to use a 3D table. Set the table axis to be ECT and Multi Fuel Blend (or Ethanol % if more appropriate).
4.Set Warm Up Enrichment Table mode to Multi-Fuel. Set the Axis to TP(Main) (or MAP) and Engine Speed.
5.Tune the engine as per the Modelled fuel tuning guide. This includes cold starts and all other normal tuning procedures.
Setup and Tune for the Second Fuel
Tuning for the second fuel is basically the same procedure as tuning for the first fuel, except using the second fuel and all the settings for the second fuel.
1.Fill the fuel tank with pure unblended second fuel. Go to some effort here to make sure there is no residual mix of fuel.
2.Set the Fuel Equation Mode to Modelled - Multi Fuel.
3.Ensure that all the new settings that become available are configured correctly for the second fuel type. Refer Multi Fuel Settings. Particularly the Injector flow and Stoich Ratio numbers.
4.Set up the Multi Fuel Blend Ratio Table. It is a good idea to start with the numbers in the Multi Fuel Blend Ratio Table linearly interpolated between 0 and 100%.
5.Copy the AFR/Lambda Target table numbers from Table to Table 2. This can be done by right clicking on the AFR/Lambda Target Table and selecting Import/Export > Export to Clipboard. Then right click AFR/Lambda Target Table 2 and select Import/Export > Import from Clipboard. Modify the numbers in the AFR/Lambda Target Table 2 to suit the second fuel.
6.Some fuel changes will not require a second Fuel (VE) Table. Radical fuel changes (eg Gasoline/ethanol) may require a second VE table. A second table can be enabled now or left until it is found that it is required. To enable a second VE Table:
1.In Fuel > Fuel Corrections > Dual Fuel Table, set the Table 2 Mode to Interpolate Between.
2.The Fuel Table Ratio Table will appear under Fuel > Fuel Corrections > Dual Fuel Table.
3.Set the X axis of this Table to Multi Fuel Blend and set the axis numbers to 0 and 100. You can choose to blend the VE tables from another parameter if desired.
4.Set the numbers in the Fuel Table Ratio Table to match the axis numbers to get a VE table blend that matches the other Multi Fuel blended settings.
7.The same process can be used for two Ignition tables if it is expected that ignition numbers will vary significantly between fuels. The setup is found under Ignition > Ignition Corrections > Dual Ign Table. Note: It may be desirable to set the X axis of this table to something other than Multi Fuel Blend if the ignition timing should not exactly track the fuel blend. Eg Ethanol %.
8.If using a Multi Fuel blended Warm Up Enrichment Table then copy the numbers from Table 1 to Table 2 also.
9.Ensure before tuning that the Multi Fuel Blend parameter reads 100%.
10.Tune the engine as per the Modelled fuel tuning guide on the second fuel. Make sure to apply tuning changes to the settings for the second fuel (eg AFR/Lambda Target Table 2, Fuel (VE) Table 2, Fuel Charge Cooling Coeff). This includes cold starts and all other normal tuning procedures.
Tuning Between Fuels
After the engine is satisfactorily tuned on both fuels, if it is desired to operate the engine at any point in between the two fuels then the fuel must be mixed in controlled amounts and a basic tuning process followed.
1.Start by running a pure mix of either the first or second fuel.
2.Mix a controlled amount of the second fuel. If using an ethanol sensor this can be done by watching the measured ethanol content while the fuel is slowly added (with the fuel pump running!). If manually mixing then care must be taken to get exactly the right proportions and to flush the tank between fuels. Steps of 10% blend are sufficient.
3.Adjust the corresponding number in the Multi Fuel Blend Ratio Table to correct the tune towards the first or second fuel as required. Tune cold start and any other fuel blend dependent parameters for this fuel mix.
4.Repeat the previous steps at each fuel mix.