So I now have V4 of the ECU TCU BinConv working with full End Of Injection calculations (But not yet posted public). Made a simple but pretty cool change today which is showing very nice early indications, but will tell over time. Driveability and torque response is subjective without a dyno (But I say is better), but the fuel economy figures are showing good early indicators. Much of my driving is start/stop in traffic.
The Drivers Wish maps takes your throttle position, compares with RPM, and outputs a desired Injection Quantity (IQ) of fuel. There are some limits, but if all is good, this is what the ECU calls for.
Fuel rail pressure maps then takes this IQ, compares it with RPM to output a desired fuel rail pressure.
Start of Injection (SOI) also takes the IQ and compares it with RPM to output a degrees before TDC to begin the injection cycle.
The Injection Duration maps then take the injection volume which is a simple conversion from weight (mg) to volume (mm3) of diesel, compares it to Fuel Rail Pressure and outputs a duration to hold the injector open for in microseconds. This mg to mm3 conversion is one of the reasons I prefer to keep the fuel filter temperature control working.
So to improve the End of Injection (EOI), increasing the rail pressure at a given IQ will shorten the required duration to inject the same fuel and create an ever so slightly higher cylinder pressure slightly earlier, giving a slightly higher average torque for the peak usable crank angle. This is not the same as the add in boxes that fool the ECU into giving more fuel. The ECU is well aware of the change and no limits are exceeded or changed, just the same quantity of fuel goes in but in a shorter time. Yes, there are a few other side effects, but that is for the smart people to argue.
The calculator below shows the result of increasing the rail pressure by 10% above an IQ of 10mg/stroke and 1400 RPM.
Rail pressure change by 10%, never exceeding the stock 1350 max. This is the actual Rail Pressure map.
Result of EOI change. This represents the change in EOI from stock tune.X axis is mg/stroke fuel, Y axis is RPM. Up to a 2 degree improvement in EOI from a basic and simple change. Increase in fuel pressure results in a shorter time to inject the very same amount of fuel.
Actual EOI output for all RPM ranges. IQ on the x axis. Degrees on the Y axis. 0 being TDC.
This graph shows the SOI and EOI at 2000 RPM. Degrees on the left, IQ on the horizontal axis. The difference between the two is the injection duration.