AuxMaps provides a set of fuel adjustments and alternate base timing and open loop fuel maps that can be configured to apply at certain times.
Ethanol sensors report ethanol content as a frequency from 50hz to 150hz corresponding to 0% and 100% ethanol content. ECMLink can be configured to use the ECU's MAF input to read an ethanol sensor's output and then adjust the fuel mixture accordingly. ECMLink can also be configured to interpolate between the MinOct and MaxOct timing and fuel tables based on ethanol content.
Doing this requires speed density operation so as to free up the MAF input for the ethanol sensor signal and, clearly, you have to add an ethanol sensor installed as well. Instructions for installing an ethanol sensor are provided online in our wiki or in our user support forum.
Once the sensor is installed and connected to the ECU, you can datalog various ethanol-related parameters to confirm operation even before you enable ethanol sensor operation in ECMLink. You can also view these parameters without starting the engine! Simply activate the fuel pump off the Misc tab to circulate fuel through the ethanol sensor so that you can test and adjust settings before starting the engine.
Log parameter | Description |
FlexFreq | Displays the sampled freqeuncy from the ethanol sensor. |
FlexEthMix | Displays the ethanol content reported from the sensor as a percentage. A number like 85% indicates an 85% concentration of ethanol in the fuel. |
FlexOctWeight | Displays the weighting given to the MaxOct tables based on ethanol content. A value of 100% means the MaxOct table is being used exclusively with no influence from the MinOct tables. A value of 50% means the MinOct and MaxOct tables are being averaged equally. |
FlexFuelAdj | Displays the amount of fuel adjusment to be applied based on ethanol content and the ECU's configuration. A value of 0% would mean that no ethanol-related enrichment is being applied. A value of 50% means a 50% ethanol-related enrichment will be applied in the final injector pulsewidth calculation. Typical values for FlexFuelAdj are somehwere from around 6% for E10 and maybe 55% for E85. But this all depends on other parameters described below. |
Enables basic ethanol sensor functionality (i.e., automated global fuel adjustment). Once checked, the ECU will start sampling the MAF input for a valid ethanol sensor signal and once found will apply an ethanol-based adjustment to the global fuel scaler defined on the Fuel tab.
Defines the enrichment value to apply when the ethanol sensor reports 100% ethanol content. When the ethanol sensor reports 0% ethanol, no adjustment is done. A theoretically correct value for the E100 enrichment is around 63%. So that's a good value to start with. But we've found in testing that various injectors actually flow less volume with increasing ethanol content. So you may find that you need to increase this enrichment if your mixture seems to get a little leaner as you increase the ethanol content of your fuel.
When checked, the ECU will interpolate between the MinOct and MaxOct tables based on ethanol content (i.e., based on the value reported by FlexEthMix). You define the two end points where MinOct and MaxOct are used and then the ECU interpolates between the two any time the ethanol content reported by the sensor lies betweent those two end points.
Typical values would be to use MinOct at E10 (10% ethanol) and then MaxOct at E85 (85% ethanol). But this is entirely up to you, as the tuner, how you want to go. Some guys like to be running on the max tune by the time they have an E50 mix. In that case, they can just put 50% into the Use MaxOct at & above field.
Specifies the ethanol content at which the MinOct maps will be used exclusively with no influence from the MaxOct maps. Any ethanol percentage at or below the value specified in this field will force the use of MinOct maps exclusively.
Specifies the ethanol content at which the MaxOct maps will be used exclusively with no influence from the MinOct maps. Any ethanol percentage at or above the value specified in this field will force the use of MaxOct maps exclusively.
Secondary Maps are a set of base ignition advance and open loop fuel mixture tables that can be activated in place of the primary maps.� These maps can be configured in the Direct Access tab.� Normally, the ECU interpolates between max-octane and min-octane maps based on learned knock retard behavior.� In practice, though, the ECU almost always uses the max-octane maps because nobody with ECMLink allows the engine to knock very long without correcting the problem.� So the min-octane maps really end up unused.
When secondary maps are enabled, the min-octane (MinOct) tables in the Direct Access tab are treated as secondary maps instead of min-octane maps.� These include the OpenLoopMinOct and TmngMinOct maps.� The max-octane maps are used the primary/normal maps and then the min-octane maps are switched in when the specified conditions are met.
Disables learned octane behavior and treats the min-octane maps as secondary maps instead.� This can be used with or without specifying additional activation criteria.� When used without criteria, this check box does nothing more than disable the min-octane maps.� When used with additional criteria selected (below), this check box enables the secondary maps when any one of the following criteria are met.
Activates secondary maps at the same time the user's custom FPS (fuel pressure solenoid) controls are activated.� Custom FPS controls can be configured using the FPS tab.� This checkbox will remain disabled until custom FPS controls are defined and saved to the ECU in the FPS tab.
Activates secondary maps at the same time the user's custom EGR (exhaust gas recirculation solenoid) controls are activated.� Custom EGR controls can be configured using the EGR tab.� This checkbox will remain disabled until custom EGR controls are defined and saved to the ECU in the EGR tab.
Activates secondary maps at the same time the IdleSw input to the ECU is active.� To use this check box, you must first simulate (or disable) the idle switch input in the RPM/TPS tab.� This checkbox will remain disabled until the idle switch is simulated or disabled in the RPM/TPS tab.� To use this function, wire a manual toggle switch to the idle switch input on the ECU so that when the switch is activated, the ECU's idle switch input is switched to ground.
Secondary Fuel Adjustments provide a staged fuel configuration where a second set of global fuel adjustment values can be applied on top of the first when appropriate conditions are met.� This can be used, for example, to activate a second bank of injectors.� You simply have to calculate the secondary adjustment values based on how much additional fuel is being injected when the secondaries come online relative to the primaries (i.e., not relative to stock injectors as you would do for the "normal" global fuel calculation).
EXAMPLE 1: If you're running 850 primaries and 950 secondaries (assuming stock base fuel pressure), then the following illustrates how to calculate the primary global fuel compensation as well as the secondary global adjustment.
Global fuel (Fuel tab): 450 / 850 - 1 = -47.1%
Secondary global adj (AuxMaps tab): 850 / (850 + 950) - 1 = -52.8%
EXAMPLE 2: Another example where this might be used is when you want to switch between two different fuel types.� If you normally run E85 but want to be able to switch to gasoline when E85 is unavailable, you can use this function to make that global adjustment automatically when you flip a switch on the dash.
To do that, simply wire in a toggle switch to the idle switch input (toggles to ground) and select to enable secondary fuel adjustments when the IdleSw input is active.� Then configure your primary global fuel compensation in the Fuel tab for the E85 configuration and configure the secondary fuel adjustment in the AuxMaps tab to convert that configuration to gasoline (you would typically use around -33% for the secondary global adjustment field to switch from E85 to gasoline).�
With that in place, you can switch to gasoline at any time by simply flipping that switch and the ECU will kick in the secondary fuel adjustments you have defined.
Enables the secondary fuel adjustment function.� This can be used with or without specifying additional activation criteria.� When used without criteria, this check box basically does nothing because no criteria can be met to activate the secondary adjustment.� When used with additional criteria (more details below), this check box activates the secondary fuel adjustments when any one of the criteria are met.
Specifies the amount of time to wait after the criteria are met to activate secondary fuel adjustments before actually doing it.� This can be useful when triggering a second bank of injectors with a mechanical relay, for example.� In such a configuration, the FPS output might be used to trigger a relay which provides power to a second bank of injectors.� But since it's mechanical, there can be significant delay (100-200ms) between when the ECU tells the relay to trigger and the time the injectors are actually activated.� You can use this field to adjust when the ECU will cut the injector pulsewidth relative to the time the criteria are met.
The adjustment to apply on top of the primary global fuel adjustment specified in the Fuel tab when secondary fuel adjustments are activated.� See example 1 above for details on how to calculate this value.
An amount to add or subtract from the deadtime adjustment specified in the Fuel tab when secondary fuel adjustments are activated.
This option makes it so that the secondary fuel adjustments are always active.� It's a little unusual to use this option, but it can be handy when running large injectors to get some additional compensation resolution.� You can set the primary global fuel adjustment to -50%, for example, and then set the secondary adjustment to get the final number you want.� By setting the primary to -50%, you're basically configuring the ECU for 900 cc/min injectors (450 * 2).� Then you set the secondary adjustment using 900 as your base injector size like so (using 1600 cc/min injectors as an example):
Secondary global adj: 900 / 1600 - 1 = -43.8%
Activates secondary fuel adjustments at the same time the user's custom FPS (fuel pressure solenoid) controls are activated.� Custom FPS controls can be configured using the FPS tab.� This checkbox will remain disabled until custom FPS controls are defined and saved to the ECU in the FPS tab.
Activates secondary fuel adjustments at the same time the user's custom EGR (exhaust gas recirculation solenoid) controls are activated.� Custom EGR controls can be configured using the EGR tab.� This checkbox will remain disabled until custom EGR controls are defined and saved to the ECU in the EGR tab.
Activates secondary fuel adjustments at the same time the IdleSw input to the ECU is active.� To use this check box, you must first simulate (or disable) the idle switch input in the RPM/TPS tab.� This checkbox will remain disabled until the idle switch is simulated or disabled in the RPM/TPS tab.
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