The picture is 4+extrapulse (never call it 4+1 please ! that is reserved for evenly spaced primarytrigger with 1 pulse sectrig ).
- Remember that VEMS is "versatile": it could be 6+extrapulse, 8+extrapulse, 12+extrapulse (suitable for 3,4,6,8 cyl), 3+extrapulse, 5+extrapulse,
- or N+extrapulse as long as integer number of normal pulses pass for each engine-event.
When used for primary trigger, it is called extrapulse trigger (supported since firmware 1.1.96)
- a low-pulsecount but relatively precise trigger
- might be a good compromise for home-made trigger wheels.
- say, 6+extrapulse is less work than 12-2
- but better than 6 evenly spaced "coil-type" pulses (which requires camsync and also, one must make sure camsync and crank pulses are not very close - that would cause problem with cambelt sloppyness).
When used for secondary trigger: also supported (eg. BMW S50 / S54 double-vanos engines variable position exhaust cam): sectrig dialog can be configured to ignore sectrig above a certain primtrig tooth ("secignore" variable).
IMPORTANT: To avoid confusion (especially when extrapulse trigger is used for sectrig), make sure to report details of BOTH primtrig and sectrig.
[2012-06-26 triggerlog] posted on Chat
- this seems 8+extratooth, (tooth width=45 crankdeg assuming
- the extrapulse splits the 45 crankdeg as 15,30
- so the full pulsetrain is: 15,30, 45,45,45,45 ,45,45,45
- config would be nice too, but as far as the trigger-settings are concerned we can make from scratch (using the bottom of primary trigger dialog, eg "honda extrapulse")
- see pulsetrain pattern
- make proper config and benchtest with 1.2.4
- and see how inj and ign behaves
See 1.1.96 ("extrapulse") on GenBoard/UnderDevelopment/FirmwareChanges