Update 09.23.2008

Audi is my favorite field. Almost half of my units run on Audis.

Last weekend my first VEMS equipped Audi brings Crew to champions!!! in Rally-sprint 4WD n/a class. It was very tight fight: both main pretenders starts this event with equal standings and gives very close SS times. Finally only 3.2s separate both. Here is results:

All my 5cyl Audis run on Auditrigger. One with strange 7A flywheel with Hall signal inverted. Maximal Rpms I ever try is little under 8000. Without errors. Almost all use 1.1.27 firmware.

What I like year later:

What I miss:

Update 09.05.2007

Put 1.1.23 firmware. Looks it works. Yes without Hall sender is possible to start/drive!

I make fine tuning on this old engine. Must say I like to tune VEMS. Configuration in nightmare, tuning is almost pleasure!

Old engine produce good power. Somewhat 15-20Hp higher than stock 170Hp. Only modifications is loud exhaust and now restrictive AFM is in the garbage!

What I like:



Flyback problem

Update: here is my solution for flyback:

7A engine use 2 Ohm injectors. ~315ccm. With resistors from factory. My mistake is install without resistors.

With flyback wire only it was completely impossible to tune. Injectors as soon as opened stays opened loooong time. Highest lambda possible 0.7

I install flyback board inside. And hope fix this problem completely. In reality things goes better, but stays far from good. This engine is for competition - no need for super-clean idle. Lambda 1.0, rough Ego control.

But without flyback (yes my mistake - two fried FETs at redline) control over injectors at idle is far far better. Idling even at lamda 1.10...1.15 !!!


So reality is: my first Genboarded cars will be Audi 20V turbo and n/a.

Here is board modifications for cramhome signal (crankhome + Hall on camshaft)



I imitate Audi Trigger using WAW file: 270 pulses on right, 1 pulse on left chanel. 1.0.53 firmware.

Everything works OK until ~6000Rpm. Then starts trigger errors. After 7000 - no sync at all.

It seems things goes even worthier with new 1.1.11 firmware.

Q: How to sort out what is cause: sound card resolution or something with Genboard?

Disquiet is because 2 of 3 Audis must rev up higher than 7000!

  1. Audi have restricted turbo by rules ~300hp max. I think ~500Nm@~3500 and ~300Hp@~5000
  2. is project with big turbo and target power >500Hp
  3. is n/a engine with deep modificatons for rallying ~250Nm@~5200 ~230hp@~6900
All 5L 20V using InputTrigger/AudiTrigger

here is my waw files:





I use Goldwave sound software. They have evaluation version: free and very sutable: simly loop .waw say 8000 times. And under tools is easy to control playback speed evenly.

Use 96000 samples/sec wav files for this 135 tooth pattern (at least if you go high RPM), not 44100 samples/sec.

third question:

Q: C30 cap between primary 135tooth VR input and ground? Is't it too big??


R56 * C30 = 18k * 1nF = 18 usec

18 usec is less than 55 usec/2, and even with a 27 usec time constant, the signal would reach the LM1815 input, just slightly lower amplitude (still much higher than needed to trigger). So this will not prevent reaching 8000 RPM.

However, if you want to reach 8000 RPM very quickly, like from 4000 .. 8000 in 0.4 sec or faster, than the adaptive hysteresis arming threshold might not be reached and trigger errors might be the result. A 7..8000 RPM revlimit in neutral gear is not a bad idea anyway.

This document: beside of all is mentioned:

...if there is noise C30 (which helps shape the input signal) may be broken, try replacing it if you don't have a scope 1nF is will give you a 16kHz filter frequency, you could easily have a bit more here for most applications....

But 16kHz is 7111Rpm for audi 135 teeth Wheel!


Update mid 09.02.2007

Another observation:


This situation I got using balance button on already "started engine": it works on 135(270)tooth signal only! No trigger errors. But reality - no second trigger signal at all.


and this is with normal mid balance and C30 soldered back


Both tests 1.0.53 and Audi_270&1_4690Rpm.wav

Keep an eye on MembersPage/MarcellGal/PowerAndTraction, we purchased a 5cyl audi (engine should jump to bay on 2007-03-09) to have all the details hammered out so installation and diagnostics becomes smooth (which it is not yet) on these nice engines.


Update 26.04.2007

My first Audi finaly runs on 1.1.22 firmware.

It is n/a 7A 20V engine. I have not time for bench tests for high revs. But in real life

BTW 7A engines crankhome sensor seems already right polarity for LM1815 input. Note that (at least AAN, but likely 3B version as well) motronic seems to run great with the crankhome-VR reversed (where they have to be reversed for our LM1815 to work).


Q: Do you have some pinout, or other info for the 7A engine (+harness) ? Is it similar to ABY/AAN/ADU or 3B?

A: I have not pinout to publish. But 7A use management from hitachi with 2 own shape connectors. Nothing similar with ABY/AAN/ADU or 3B in this plan. But trigger patern is the same.