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Project Description

After a mammoth delay, I am now looking at installing in my new ride, an AAN powered Audi UrS?4.

AAN solution

I have seen there is a plug and play AAN solution available from the webstore, but am wondering what is required to modify my existing system kit (v3.2) to get the same result.

Obviously I will need a new connector and faceplate, what do I need in terms of the auditrigger?

AudiTrigger/CamHALLInverter might be a good idea, because it makes the setup less picky with noise or bumps related to flywheel shape.

Follow the AAN column in the spreadsheet on VemsAudiAan (otherwise non-standard ignition, injection and other settings would apply).

Trigger brainstorming

As you see, 5 pulses per cam rotation would be enough to get the car rolling, but there are clear advantages of a more advanced setup.

Answered Questions

Crank Sensor

  • the SHAPE of the missing tooth makes a difference with the adaptive hysteresis. A naive implementation where the tooth is simply left off, results in higher amplitude at the missing tooth. Look at a bosch 60-2 wheel:
  • the gap depth of the missing tooth should not be as deep as the gap of a normal tooth
  • the max depth of the missing tooth reached only at the middle (gradually), not with a sudden step !

WB02 calibration

For the WBO2 heater PID settings, the feedback comes from the measured nernst Ri value. The dimension is not Celsius, but resistance (maybe 0.6 Ohm or something similar?), where resistance gets lower as sensor temp rises.

Crank sensor

I'm looking at using a VR sensor to pick up on a 60-2 toothed wheel which will be attached to the crank pulley.

If you have a spare EC36 pin, it might be a good investment to have a separate pin for VR- that is connected to GND near the LM1815 chip (not through the EC36-pin26 GND). The idea is to keep signal seen by LM1815 very clean for best low RPM (<200 RPM , small signal) behaviour. Although EC36pin26 GND is not as noisy (by far) as the GND5 decreasing it further might be a good investment if the free EC.. pin is available and ECM unassembled. EC.. is perfect, just sharing current paths might (which is common for GND) inject some noise (that is usually below problematic limits).

MAP Sensor

I recommend mounting MAP on the top of the board. Better for getting the tube through the frontplate. Note that MPX4250AP pins must be bent to the other direction depending on the top/bottom (so that notched pin is close to AVR in any case)