Key To The SDS Map<\/strong><\/p>\n\n\n\nRPM\/Fuel Factor<\/strong><\/p>\n\n\n\nThe first major element of my table controls fuel flow based on engine RPM. Your will see a FUEL FACTOR associated with each engine RPM value in 100 RPM increments. In each case the factor is 140 except for 2600 and 2700 RPM. For these values, the factor becomes 231. The increase at high RPM reflects the need for additional fuel at high power settings. By increasing fuel using the MAP, there is typically no need to manually enrich the engine during take-off. The 140 fuel factor represents what is necessary during normal cruise operations. <\/p>\n\n\n\n
I modified these values when tuning my engine AFTER break-in. However, during break-in, I manually varied the mixture to control CHTs and to ensure the engine was receiving sufficient fuel for take-off.<\/p>\n\n\n\n
Manifold Pressure \/ Fuel Factor<\/strong><\/p>\n\n\n\nThese table entries adjust fuel flow based on the selected manifold pressure. You will notice that except for the first two entries, the fuel factor increases as manifold pressure increases. This is logical as higher manifold pressures require more fuel to make the increased power demand.<\/p>\n\n\n\n
The first two entries in the this table typically come into play only when there is a Manifold Atmospheric Pressure sensor (MAP) failure. If the MAP Sensor fails, the ECU will fuel at near full throttle levels as a safety measure. It is essential to keep to keep the engine operating if the MAP sensor fails. <\/p>\n\n\n\n
Readers are cautioned to never<\/strong> change low RPM \/ low manifold pressure values as these values are essential too keep the engine operating in the event of a MAP sensor failure. See the SDS Lycoming Tuning Guide for more details.<\/p>\n\n\n\nThese factors used were not changed.<\/p>\n\n\n\n
Engine Temp \/ Fuel Factor<\/strong><\/p>\n\n\n\nThese table entries are usually only used to increase fuel to the engine when the engine is cold. You will note that as the temperature of the engine increases, the fuel adjustment tapers off. Once the engine is at normal operating temperatures (176F and above), the factor goes to zero.<\/p>\n\n\n\n
The factors used were not changed.<\/p>\n\n\n\n
Start Temp \/ Fuel Factor<\/strong><\/p>\n\n\n\nThese table entries are usually only used to increase fuel to the engine when starting based on the engine temperature. When the engine is hot, there is little adjustment.<\/p>\n\n\n\n
The factors used were not changed.<\/p>\n\n\n\n
RPM \/ Ignition Timing<\/strong><\/p>\n\n\n\nThis table determines the engine timing in degrees before top dead center (BTDC). At lower RPMs, the timing is reduced to allow better combustion of fuel \u2013 slower RPMs mean there is more time for fuel to burn so ignition can be delayed somewhat. At normal cruise RPMs (at or over 1500 RPM), the timing becomes 24 degrees BTDC which is the recommended value for my engine. It is what would be used if magnetos were installed.<\/p>\n\n\n\n
The factors used were not changed.<\/p>\n\n\n\n
IGN RET-ADV\/LOAD<\/strong><\/p>\n\n\n\nThese factors allow ignition timing to be changed through a range of Manifold Pressures. In my case I do not use these table entries. In my opinion, there is no need to use these values as my timing is optimally set when cruising at 2400 RPM regardless of what Manifold Pressure is being used \/ achieved. By setting these values to zero, engine tuning is also simplified \u2013 particularly tuning for Lean of Peak (LOP) operations.<\/p>\n\n\n\n
All values set to zero.<\/p>\n\n\n\n
Air \/ Temp<\/strong><\/p>\n\n\n\nThe Air \/ Temperature factors adjust fuel based on the Outside Air Temperature (OAT) measured by the ECU OAT sensors. As air becomes colder, it\u2019s becomes denser and therefore more fuel is required to maintain the desired Air\/Fuel ratio.<\/p>\n\n\n\n
No change was made to these values.<\/p>\n\n\n\n
Other Single Entry Values<\/strong><\/p>\n\n\n\nThere are a number of other values that can be set using the SDS programmer. The values below represent the parameters that were available in my ECU as of 2022. Future changes to the ECUs will likely introduce new parameters not reflected below.<\/p>\n\n\n\n
Always consult SDS documentation before changing any of these parameters. Incorrect parameters can cause serious problems.<\/strong><\/p>\n\n\n\nIn almost all cases these values will be set by SDS and should never be changed. Usually you will only want to change the:<\/p>\n\n\n\n
\nFuel Trim<\/em> Parameters for Cyl # 1 to 6<\/li>\n\n\n\nLean with Pin 13 \/ Ign Advance Switch<\/em> (% fuel change when LOP)<\/li>\n\n\n\nPin 13 Aux Input Advance Switch<\/em>, Most people use use LOP button on programmer to activate.<\/li>\n\n\n\nAdvance Switch<\/em> which specifies ignition advance when running LOP<\/li>\n<\/ul>\n\n\n\n\n
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Parameter<\/th> Value<\/th> Purpose<\/th><\/tr><\/thead> Start Cycles<\/td> 20<\/td> Control fuel enrichment during cranking and the first few seconds of engine running after starting. Typical values of around 20 are appropriate.<\/td><\/tr> ACCUPUMP HIRPM<\/em><\/td>20<\/td> Adjusts fuel flow when there is a rapid increase in throttle angle above 1750 RPM (dramatic increase in throttle)<\/td><\/tr> ACCUPUMP LOWRPM<\/em><\/td>40<\/td> Adjusts fuel flow when there is a rapid increase in throttle angle below 1750 RPM (dramatic increase in throttle)<\/td><\/tr> ACCUPUMP SENS<\/em>E <\/td>5 <\/td> Sets ECU sensitivity to changes in the throttle angle<\/td><\/tr> CLOSED LOOP<\/em><\/td>OFF<\/td> Closed Loop not used in aircraft installations<\/td><\/tr> CL RPM LO<\/em> <\/td>1200<\/td> Value ignored, not used in aircraft installations<\/td><\/tr> CLR PM HI<\/em> <\/td>2400 <\/td> Value ignored, not used in aircraft installations<\/td><\/tr> CL MAP LO<\/em><\/td>16.3<\/td> Value ignored, not used in aircraft installations<\/td><\/tr> CL MAP HI<\/em><\/td>24.2<\/td> Value ignored, not used in aircraft installations<\/td><\/tr> Fuel Cut \/ MP<\/em><\/td>No Limit<\/td> Cuts fuel to engine is specified MP is exceeded<\/td><\/tr> Fuel Cut \/ RPM<\/em><\/td>3000 <\/td> Cuts fuel to engine if specified RPM exceeded<\/td><\/tr> Idle TP Location<\/em><\/td>Not Used<\/td> Throttle position at idle<\/td><\/tr> Idle Fuel Amount<\/em><\/td>Not Used<\/td> Fuel factor at idle<\/td><\/tr> Lean with Pin 13 \/ Ign Advance Switch<\/strong><\/em><\/td>-8% Enabled<\/td> Enables LOP switch \/ specifies % amount to lean when LOP<\/td><\/tr> RPM Switch on at<\/em><\/td>2300<\/td> Not used in aircraft installations<\/td><\/tr> Fast Idle<\/em><\/td>167<\/td> Not used in aircraft installations<\/td><\/tr> Radiator Fan Off<\/em><\/td>36<\/td> Not used in aircraft installations<\/td><\/tr> Radiator Fan On<\/em><\/td>33<\/td> Not used in aircraft installations<\/td><\/tr> O2 Type<\/em><\/td>PLX, AEM(Old)0-5V<\/td> Type of O2 Sensor Installed<\/td><\/tr> Pin 13 Aux Input Advance Switch<\/em> <\/td>Advance Switch<\/td> Specifies if LOP advance switch installed<\/td><\/tr> Advance Switch<\/em> <\/td>6<\/td> Specifies additional ignition advance (degrees) when running LOP<\/td><\/tr> Lean Warning<\/td> Disabled<\/td> <\/td><\/tr> Gauge Button<\/td> Guage1<\/td> Sets Gauge selected when Gauge button pressed on ECU programmer<\/td><\/tr> Magnet Position <\/em><\/td>97<\/td> Timing magnet position of primary ECU supplied by SDS. Value is 88 for <\/em>secondary ECU. <\/em>USE SDS SPECIFIED VALUES FOR YOUR INSTALLATION.<\/strong><\/td><\/tr>Ignition Related<\/span><\/strong><\/td> <\/td> <\/td><\/tr> Knock Retard <\/em><\/td>0<\/td> Not used in aircraft installations<\/td><\/tr> Knock Sense <\/em><\/td>1<\/td> Not used in aircraft installations<\/td><\/tr> Knock Max RPM<\/em><\/td>3800<\/td> Not used in aircraft installations<\/td><\/tr> Crank Retard <\/em><\/td>15<\/td> Not used in aircraft installations<\/td><\/tr> Setup Mode<\/u><\/em><\/strong><\/td> <\/td> It is important that these values are never changed<\/u><\/em><\/strong><\/td><\/tr>Air temp Sensor<\/em><\/td>GM F<\/em><\/td>Set by SDS – Type of outside air temperature sensor installed<\/td><\/tr> Map Sensor<\/em> <\/td>1 BAR IN<\/em><\/td>Set by SDS – Type of manifold pressure sensor installed<\/td><\/tr> Fuel Flow <\/em><\/td>0<\/td> Not used in aircraft installations<\/em><\/td><\/tr>MISCSW2CTL<\/em><\/td>4<\/td> Set by SDS<\/td><\/tr> Config 1<\/em><\/td>4<\/td> Set by SDS<\/td><\/tr> Config 2<\/em><\/td>0<\/td> Set by SDS<\/td><\/tr> Config 3<\/em><\/td>64<\/td> Set by SDS<\/td><\/tr> Config <\/em>4<\/td>128<\/td> Set by SDS<\/td><\/tr> Config <\/em>5<\/td>0<\/td> Set by SDS<\/td><\/tr> Config <\/em>6<\/td>2<\/td> Set by SDS<\/td><\/tr> Config <\/em>7<\/td>1<\/td> Set by SDS<\/td><\/tr> Config 8<\/em><\/td>0<\/td> Set by SDS<\/td><\/tr> Batt Calibrate<\/em><\/td>0<\/td> Set by SDS<\/td><\/tr> RS232 Rate<\/em><\/td>0<\/td> Set by SDS<\/td><\/tr> RS232 Baud<\/em><\/td>9<\/td> Set by SDS<\/td><\/tr> AFR Offset<\/em><\/td>0<\/td> Set by SDS<\/td><\/tr> ACCP Extra INJS# <\/em><\/td>5<\/td> Set by SDS<\/td><\/tr> ACCP Extra INJS\/<\/em>TP<\/td>25<\/td> Set by SDS<\/td><\/tr> ACCP Extra INJS Am<\/em>t<\/td>60<\/td> Set by SDS<\/td><\/tr> RPM Range<\/em><\/td>4500<\/td> Set by SDS – Maximum engine RPM<\/td><\/tr> Fuel Pulse Out<\/em><\/td>340<\/td> Set by SDS<\/td><\/tr> Fuel Pulse Inj Lag<\/em><\/td>1180<\/td> Set by SDS – Time between injector pulse and injector opening<\/td><\/tr> Engine Temp Sensor<\/em><\/td>Dale 1\/8 NPT<\/em><\/td>Set by SDS – Type of engine temperature sensor installed<\/td><\/tr> Baro Fuel Compensation<\/em><\/td>1.5%\/1000<\/em><\/td>Set by SDS – Fuel adjustment (%) per 1000 ft change in barometric pressure<\/td><\/tr> PIN 13 MAP Limit<\/em><\/td>25.1<\/em><\/td>Set by SDS – Maximum manifold pressure at which Lean of Peak can be turned on<\/td><\/tr> System<\/u><\/em><\/strong><\/td> <\/td> It is important than these values are never changed<\/u><\/em><\/strong><\/td><\/tr># of Cylinder<\/em>s<\/td>6<\/td> Number of engine cylinders<\/td><\/tr> SDS Model<\/em><\/td>Type \u201cF\u201d Fuel & Coilpack II<\/td> System Model<\/td><\/tr> Burn #<\/em><\/td>7148<\/td> Software build number<\/td><\/tr> SW Version #<\/em><\/td>29.4<\/td> ECU software version<\/td><\/tr> Nitrous RET\/TPS<\/em><\/td>156<\/td> Not used in aircraft installations<\/td><\/tr> CL Loop Eng Temp<\/em><\/td>152<\/td> Not used in aircraft installations<\/td><\/tr> Staged Time<\/em><\/td><\/td> Not used in aircraft installations<\/td><\/tr>