Hi JoeTe,
I wonder if the C30 uses higher flow injectors and that is part of the reason why their SOI moves forward a bit? Really need to see the duration maps too as they do work together. I also wonder if the difference your mate heard with the 0 - 5 - 10 deg EOI was Knocking?? An EOI right at TDC 0 deg seems very brave to me. That means all injection, combustion, and pressure rise is happening during the compression cycle while the piston is still moving up. That must put some strain on the crank and conrods.
I think people who compare diesel and petrol tuning might not be looking at it correctly. In our diesels, we get a nice long burn that "normally" should last a similar time to the duration of injection. So with the fuel rail pressure map, we can control how fast or slow our burn happens, how long the burn takes. In a petrol, the burn happens in an semi-uncontrollably fast way right after the spark plug fires.
With the M mode in the gearbox. We do have 3 different gear change schedules in out TCU. My understanding is one is for high range (the one I play with), 1 for low range, and the other is unused.
I know for sure that input pin 3 on the TCU is the summer/winter switch on one of the Mercs, but for us it is used for one of the gear selector positions from the shift lever. I never really use low range, so I have toyed with the idea of just having a switch in the car with the correct resistors in it to mimic the transfer case switch. Change the low range ratio in the TCU to 1:1 to avoid any ABS sensor faults. Then, I could change the switch position from high range to low range while keeping the transfer case in high range. This should map select both different change maps in the TCU and different Drivers wish maps in the ECU. So sports/economy mode. What the downside would be that if ever I actually put it into low range, then the TCU would now see a ratio fault and go into limp mode. This is the main driver for me want to be able to modify the TCU running code. Then all problems would go away and I could have the best of both worlds.
As for the state of play with SOI. I am back to needing to do more research.
Turns out there is a big difference with SOI when converted using a time based to crank angle conversion, or using the fixed multiplier mentioned earlier. What is weird though is that the results produced in much of the map is similar, but the centre right is way way different. Way too different for my comfort.
Time based on the left, fixed multiplier on the right.
The differences between them.
