Latest summary:
VEMS team implemented a special firmware solution for Maserati startup
- "kickstart motorbike style fire-at-pulse" and made the transition to normal running reasonably graceful.
- Was quite some work, but seemed essential for good support of this trigger so we didn't settle on "running-good": a Maserati with VEMS must be able to set up to always start good.
- maybe it can be applied to Viper if we get input on Dodge Viper (Phil's feedback on Maserati was awesome)
- note that newest 1.2.6 (at least 2012-10-04 or later) is recommended (wbo2 change), in any case check that wbo2 is actually measuring
This page was used for conversation during the implementation and testing, mostly historical now. We will do some cleanup on MembersPage/OddFireSixCyl and post good config (and related ign/inj output wiring for the Maserati firing order).
..July 2012..
I did the full install of the wasted spark ignition on the engine biturbo, the injection being still done by the OEM IAW Weber ecu of the biturbo. The coil I used was the Bosch 3x2.
I had run the Vems ignition through the distributor for about 3000 km. I made the OEM Microplex Marelli ignition ecu (2 oem ecus : one for the injection, one for the ignition) to run in // with Vems and I got a switch to commute the origin of the firing signal to the coils (there are 2 on the biturbo). I did so for two purposes:
1) to keep the benefit of the knock control of Microplex
2) to start the engine faster in a quarter of a turn with the Microplex instead of the 2 revolutions and more( yes 4 pi) given by Vems ( fw <= 1.2.5 , that was before the "kickstart" implementation ).
There has been some discussion about this sluggish start here http://www.vems.hu/wiki/index.php?action=find&find=MembersPage%2FFPhil%2FInstall where one might say that DIS was the cause of it. However without DIS I get the same results and even worse because of the wasted sparks
Wasted spark
Wasted spark for this odd engine is not obvious. The best that one can do is to pair cylinders in such a way that one cylinder is TDC and the other one is 30 deg admission.
- This works since, the gas "resistance" in the exhausting cylinder is rather low, and 90% of spark energy goes to the cyl with fresh charge waiting to be ignited.
Results
- Bench test
The test is done by increasing from zero the level of the z012 triggers signals.
One sees:
- the 2 sec trig from the cam pulley per each revolution (4 pi)
- the 6 pairs of prim trig per each revolution: 3 pairs are on the crank pulley 90-30-90-30-90-30
- odd firing 150-90-150-90-150-90
- first fire after 2 revolutions (and more)
-> It is unclear to tell which sec trig from the cam pair is used
-> I checked another config: TDC delay after trigger 10 deg, spark delay 30,0,30,0,30,0 which should give the same. For some reason, the fire comes 30 deg sooner.