AAN primary trigger settings-query (Firmware 1.1.27)

[Dylan@AM Racing]

So we have been doing some upgrades on our S4 the last while, which include:

1. Garret GT3588 turbo
2. Surge tank and Bosch 004 fuel pump

Problem: Since receiving my Vems PnP unit the vehicle would not start and with some changes to the ignition outputs I got it started. I have had to make changes to get the ignition timing correct. I am still not convinced that I am correct. I am getting very high egt's (1080 deg C at 2.2 bar boost) in the manifold. I have put more timing into it without detonation (27 deg at 280 kpa at 6800rpm) and this is with a pump fuel/methanol blend.

Now the standard S4 and ALL other set ups that I have seen use the following Primary Trigger Settings (MY SETTINGS):

TDC after trigger (deg)   57.0  66.0
Number of teeth on wheel  90  90
Trigger tooth   0  8
Next trigger tooth   18  18
Crank min.period (usec) 0 0


Now I don't want to have a melt down in the motor. Any ideas?

[mattias]

Sounds like your cam sync is off by one cam revolutio. Sure you mounted it correctly?

I don't know if that's possible on the AAN motor, but with 3B and cam sync in the distributor it's quite possible and can bite you in the a**.
It's quite noticeable - you have to shift the ignition order.

It's quite easy to calculate.. next cylinder one crank revolution away is ~130 degrees from TDC, while in the correct case is ~58 degrees (57 in your example). If you check your settings it confirms what I said because :  8 teeth times 8 degres + 66 degrees = 130 degrees.
And calculating from the correct setting :  58+144+144+144-360 = 130 degrees.

It's not clear to me, did you ever use a timing light ? Always use one. I know it can be tricky with coil-on-plug, but it can be done and must be done.

[Dylan@AM Racing]

I am running external Bosch coils with HT leads. So checking timing is easy. I did check it with a timing light and got it right using the values I showed above. Ok so its back to the drawing board to reconfigure the ignition outputs.

[GintsK]

Isn't direct Hall vs inverted Hall?

http://www.vems.hu/wiki/index.php?page=AudiTrigger%2FCamHALLInverter

[Dylan@AM Racing]

I have started using Vemstune and it is pointing me to a bunch of stuff:

1. Tooth  wheel width
2. Sec. trigget HALL dirac filter
3. Coolant fan temp too high

What should i do with the hall sensor settings? I have reconfigured my primary trigger settings_ no start
I have moved the ign outputs around_no start

 

[mattias]

No start? That's irrelevant, unplug the injectors and get the ignition timing strobed and double-checked first.
I find the marks on the flywheel suck. Make your own on the damper at the front of the engine instead, mark the damper where the piston is 10 mm down the bore before/after TDC and put the mark in the middle of those two (white paint is more permanent but tape works).

Were you using VemsTune previously, and with which firmware? What firmware version are you using now ?

If you upgraded from below 1.1.85 with an old VemsTune you may be in "safety" mode, no outputs will be enabled to help save your engine in case of a bad config.

GintsK, he should have an ECU with cam hall inverter in place if it's made recently (doesn't say if he bought it recently but unless it's taken 3+ years since receiving it to start the car, ...).

[Dylan@AM Racing]

firmware 1.1.27
ecu just over 1 year
latest version of vems

[mattias]

Get a proper TDC mark made on the front pulley, and double check the timing.

You can run as is if you want, but my guess stands - your camsync signal is one rotation off, forcing you to shift the ignition outputs one crank (+ some primary trigger changes due to 5 cyl = 144 deg spacing).

[boostd audi]

without a timing light your really guessing.

[Dylan@AM Racing]

I have a mark on the front pulley and checked with a timing light. With those settings it is 100%. We had a track day today and went well. My egt's were never more than 900 deg c in the manifold. I will rethink the ign outputs and the phasing story.

[Dylan@AM Racing]

My thinking would be to turn the cam through 180 deg which would change the phasing. Any thoughts?