MembersPage/JorgenKarlsson/AudiStwo

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 2.2L 5cyl 20VT "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:

Firing order: 1,2,4,5,3

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.

Note that 1.1.x does not officially support distributor yet. It can work, but keep a few things in mind


1.1.22 airtempsensor calibration:

I fitted a 510ohm resistor in parallel with the 2700ohm pullup to get the recommended 428ohm pullup.

I used the 2252_256 file from: http://www.vems.hu/files/Firmware/release/ptc_airX_cltfactor.zip but found that it seem to be built for 490 ohm.

Can I expect a temp sensor curve for he recommended 428ohm pullup or should I replace with 490ohm to match the current file? This car can be mapped well enough for now and remapping it if the new file arrives within a week is no problem. -Jörgen


1.1.22 Auditrigger testing 2007-04-26.

440cc injectors and 4 bar fuel pressure, this is standard for the RS2.

Dump of some information and also some snapshots of wheelerror counter at the end of the file: http://www.vems.hu/files/MembersPage/JorgenKarlsson/AudiS2/20070426223513_dump.txt

There are at least one significant error in the configuration, the dwell is set too high for the available time at the max rpm. As 1.1.22 doesn't support distributor engines properly this cause loss of ignition at around 7200rpm. By lowering dwell a bit the rev limit can be set higher. On coil on plug engines the dwell can be kept at 3ms (allthough the coils on the coil on plug engines will likely like a bit less dwell.)

The WBo2 failed for some reason when we did some highway testing, it was late and we haven't checked what went wrong yet. I will check that nothing is wrong in wbo2 config.

Update: The WBo2 problem was caused by the sensor body being overheated. All air that reach the outside of the sensor has passed between the head and the wastegate or between the strut tower and the wastegate. This is not very related to exhaust temperature as it would not happen at high speed testing, but it would happen when we let off and cruised afterwards. The sensor recovers when it has cooled down. -Jörgen


1.1.22 Auditrigger testing 2007-04-25.

After updating the configuration with these setting the car started and ran with an ignition cut once in a while. After tuning the fuel somewhat while warming the engine the ignition stopped cutting. I suspect trigger errors but was not able to reproduce them when logging the wheelerrors.

The car now ran very smooth and the ignition seemed fairly stablem, not rock solid but more like +-0.5deg at idle.

I have NOT fully indexed the car yet as wednesday is when we go to a car meet. The car sounded smooth enough for us to dare to carefully drive it to the meet even if it was not indexed.

I dry-reved the car to somewhere above 5k while checking the wheelerror counter in the terminal. It was fixed at W00. I need to fully index the ignition before going further.

This car will hopefully be done and reliable on May 5th as he is attendig the same track day as me on Mantorp Park.


N+1 bench testing - TODO: move this, belongs to a subpage of InputTrigger/MultiToothNoneMissing

Config for 1.1.27 firmware 24+1 (started from Toyota Supra 24+1 config)

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 ).


10+1 trigger, config for 1.1.27 firmware - TODO: move this, belongs to a subpage of InputTrigger/MultiToothNoneMissing

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: (note that this was before 1.1.22! so config was different)

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...