MembersPage/JorgenKarlsson/AudiStwo (2007-03-19 13:36:11)

Audi S2

This car is owned by a friend and I have been able to use it for some AudiTrigger testing. It has been a slow project as it's hard to allocate garage cycles.

It's a clean car with mostly handling and brake modifications but the 3B engine was recently upgraded with some RS2 parts and a slightly bigger then RS2 turbo. The car is used on the road and for trackdays.


Engine managment specifics:

Ignition type: Distributor with Audi stock coil and stock powerstage. Driven with Stepper output A with no resistor in between. This is very similar to how Autronic drive ignition modules and active coils in all applications.

Ignition set up like if it was a coil on plug setup but with the same output for all positions. I think that we need an ON/OFF for overlapping dwell.


10+1 bench testing: 2007-03-18

Config for 1.1.11 firmware 24+1

1.1.x firmware

These should not surprise anyone:

After the (secondary trigger) campulse (taken from the middle cam transceiver; not the other cam transceiver at cyl6 that was 360 crankdegrees offsetted), the (primary trigger) cranktooth is named tooth0 (first, topmost entry in the example h[1] reftooth table). Tooth 4,8,12,16 and 20 follow, in this order (going from bottom to top in MegaTune).

128 degrees (trigtooth=1 + ign_tdcdelay=98 crankdegrees) after tooth0 we have the TDC of cyl2 (connected to channel 1 in our example, that is 0x10 in the first entry of the h[2] ignition output table ).


Config for 1.1.11 firmware 10+1

These should not surprise anyone:

1 A 10

2 B 20

4 C 30

5 D 40

3 E 50


Auditrigger testing 2007-03-11:

Final configuration taken from the car + log + mlp02mll capture of wheelerror: http://www.vems.hu/files/MembersPage/JorgenKarlsson/AudiS2/AudiS2_2007-03-11_bad_igntiming_wheelerrors.zip


Auditrigger testing 2007-03-10:

The more or less undocmunented 1.1.18 auditrigger configuration caused some trouble initially but it was solved after making some questions on IRC questions.

http://www.vems.hu/files/MembersPage/JorgenKarlsson/AudiS2/Audi_3B_synking_but_timing_is_very_late_when_cranking_low_batt_stopped_tests.zip


Auditrigger testing 2007-02-23:

Secondary trigger

Tested secondary trigger and found that even with C40 upgraded to 1.2uF it does not prevent false triggs during the last third of the rev. This was very clearly seen on the scope.

A weak pulldown of 2.7k was fitted (1k resistors not available during the test) and the mode jumper was used to connect pin 5 of the secondary trigger 1815 to 5v. This removed most of the magnetic noise from the speed sensor wheel and improved signal quality a lot.

Signal was still very strong and for the next test a 1k resistor will be used.

Primary trigger

I forgot about that I configured the pulse length for the output signal to be shorter on the primary trigger, this resulted in a scope setting that was to slow to reliably see all pulses. The pulselength is now ca 30us with R57=33k, R57 is normally 75k which will prevent high rpm operation with Auditrigger.

This had the benefit of me scoping most signals around the LM1815 chip. The signal on the adaptive thresold pin (pin7) was interesting:

Add pin7 scope plot here.

When charging the capacitor the current is pulsed, with R181=150k this results in a very strong sawtooth signal. For Auditrigger R181 is most likely not needed and I bridged it in this application. We need to review this to check if it can cause problems!!! An additional capacitor to even out the signal could improve performance.

So far the tests has been run with R56=18k (has to be changed to 10k), no pulldown (1k will be fitted, signal is VERY strong at cranking).

Ignition:

Something is wierd with the ignition output, possibly an inductive load somewhere on the wire to the ignition powerstage. I didn't have time to investigate in the middle of the night. It produced a 0.5v negative sharktooth instead of a 5.6v positive square pulse. Very tired...