Playing around with the 2.7 software (ECU and TCU)

[703JRB]

Originally Posted by Adrian D

If you can read it, I can do it remotely. You need a KTAG interface to read the TCU.

Flat cost of 105USD. If you can't read it, there are 2 options: ship your TCU or I ship you a used TCU at the cost I can get them (around 30-40USD).

I should be able to read it. Would this include tuning or just the ratio change?

Cheers Joe

[RTB]

Well, unless someone can give me a better app for measuring 0-100 times, looks like I am done.

3 runs below 9 seconds, 1 above. Each start I chirp the tyres. The run above 9 seconds actually resulted in wheel spin on dry roads with 265 AT's, full fuel tank. This can be clearly seen in the data. Diff took up and grabbed it pretty quickly.

8.3 sec, 8.8 sec, 9.9 sec, 8.9 sec

Wheel spin can be seen with the 1.8 seconds to 27 km/hr. Longest time for this speed by far showing delay getting off the line.



There is something a little weird I don't understand though. I get a small amount of smoke when I tramp the throttle. Small enough that it is not visible during the day, only at night in the headlights behind me. I'm not a fan of smoke, so I lowered all the IQ values in the smoke map to reduce the max amount of fuel injected until the boost builds. Just did it as a direct ratio to boost pressure. Most values only decreased by no more than 5 mg/stroke (~10%). Plan is to reduce by 20% to match the amount of fuel that I measure going in versus what the ECU thinks is going in.

1st gear noticeably revs out quicker and I think is the primary reason for the change in times. Boost response is improved. My boost used to build ramping up to set point. Now it rises much more quickly. I even get little boost overshoots occasionally.

How???? I can only think it might have something to do with more efficient use of the turbine and allowing slightly higher exhaust flows, but that might be clutching at straws. Smoke map uses current boost to set a max fuel. This max fuel then limits how much more boost can be called for while it waits for the turbo to produce the actual boost being asked for. As the turbo produces more boost, the smoke map allows more fuel. So basically the target set point for boost is always closer to the real boost with a lowered smoke map. I would expect it would mean slightly more open VNT. Also, maybe just due to being a better AFR? With too high a smoke map, the AFR would go too low maybe? Reducing the smoke map would result in a better AFR during boost building times. The smoke map basically sets the minimum AFR.

Loving the new excel ECU reader. 246 value changes to the maps with a couple of formulas and a click of a button. That would have taken ages the old way.

[Adrian D]

Originally Posted by 703JRB

I should be able to read it. Would this include tuning or just the ratio change?

Cheers Joe

Tuning, ratio change, you name it, it's all in the same price

[RTB]

Not as fancy as the last video posted here, but good enough.

https://youtu.be/N8nXREU0rPc

The last 8.9 run shown.

[RTB]

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.