MembersPage/OddFireSixCyl (2011-05-18 17:36:16)

Odd fire 90,150,90,150,90,150 degree V6

Now even the factory 30,90,30,90, ... factory maserati trigger is supported even with the dual camsync pulse (1.1.90 firmware). See below.


Non-maserati triggers

Common denominator is 30 deg, which suggests 12 teeth on crank (also called 24+1 pattern with Tools/Play-trigger type c024)

Bench tested configs using per cylinder spark delay:


Maserati factory trigger setup primtrig pattern 30,90,30,90,30,90, 30,90,30,90,30,90 with double camsync pulse

[Maserati biturbo .wav] made by Phil.

For the curious:


Reftooth-based solution might be another option WARNING: not yet passed testing with missing tooth + uneven odd-fire reftooth table !

With the missing-tooth primary trigger even the multiple-tooth camsync is no problem for recent firmwares using proper "sectrig ignore" value as on MembersPage/DamirMuha/MagnetMmarelliCamSensor

As you see, that method is about


Page needs to be cleaned up


SOMEWHAT OBSOLETE SPECULATION: Another chance to get 1.1.x working on this trigger is using divby2 with the "auditrigger" (because that is a pre-divider: divides before the pulses are considered giving 120,120,120,120,120,120 pattern). But than quite extreme per-cylinder ignition trimming (60 deg delay every 2nd cyl) is needed for the 90,150,90,150,90,150 result.

  • as 1.1.x firmware tries to time from the last tooth and expects constant spacing between teeth (except at the missing tooth, or missing teeth). The InputTrigger/SubaruThirtySixMinusTwoMinusTwoMinusTwo and the uneven old-lancia/fiat and subaru has separate implementation in 1.1.x (while the maserati still does not have a dedicated handler)

The solution to set 30 crankdegree teeth on the crank pulley was also recommended by Matthias on [Vems uk]

This is the reply I have posted

"The sensors are VR but it is not a big problem to make a Hall signal from them"

I can filter out one of the crank trigger or even I can divide the triggers by two to make 2 x (1cam trig +3 crank trig) each for one even fire 3 cylinders, for respectively the left bank and the right bank of the engine . But in this last case I need 2 GenBoards !!!

This is what Maserati has done for the late biturbos: 2 triggers + one ecu (ignition+injection) for each bank

The 30,90,30,90,30,90, 30,90,30,90,30,90 arranged according to ign events, trigger tooth marked bold:

The good news is that if firmware userspace "triggertooth" calculation can be taught about the uneven tooth-times (modifying the userspace easier than the interrupt timing code state machine), that might provide an 1.1.x solution without the per-cylinder spark delay tweak.