Subpage of Base setup menu

Ignition settings

These setting influence the ignition pulse generation of the VEMS ecu, ignition is scheduled from last possible occasion to get very accurate and precise ignition timing on all running conditions. Between channels overlapping dwell is used, but only when ignition output selection allows it (no collisions allowed) and desired dwell requires it, example:

• simple trigger no cam sync, no overlap
• multitooth wheel with or without camsync or simple trigger (with or without camsync), but only one output in use, no overlap
• multitooth wheel with or without camsync or simple trigger + camsync, but only cyl_nr/2 output in use (and all different), overlap, but max 360_degree_time - minimum_off_time
• multitooth wheel with camsync or simple trigger + camsync, but cyl_nr output in use (and all different), full overlap, but max 720_degree_time - minimum_off_time

Ignition outputs

Ignition Outputs In Use
Select how many ignition outputs to use in the Ignition Output Table.

Ignition Driver Type
Use Normal for all conventional ignition systems, EDIS is only used for custom PnP solutions.

Invert Driver Output
Normally disabled, use if you need inverted outputs. Only for experts!

Dual Output Mode
This function enables "virtual wasted spark" and will drive two ignition outputs at the same time. See Ignition Outputs Dual menu when assigning outputs in this mode.

Multi Spark
This enables multispark and will deliver multiple sparks per ignition output when engine rpm is below 1500 rpm (over a 25 degree relative window from first spark position); The amount of deliverable sparks are calculated by these boundries according to commanded dwell and seperation time.

Other

Ign Adjust - Cold
Adjusts ignition timing on a cold engine, the adjustment is ramped down from 0 degC to warm engine.

Ignition Retard Clamp
The minimum ignition timing allowed, used to clamp ignition timing for ALS and launch control. Typically 0 down to -20 degrees.

Ignition Dwell Settings

Coil Charge Time @13.2V
This sets the ignition dwell time, set this according to your ignition coil specification. Normal values are 1.5 to 3.0 ms. Too high values will overheat your coils! Take care and use correct fuse size.

Coil Charge Time MAP Scale

Dwell is extended by (MAP - 70kPa) * Coil Charge Time MAP Scale/4096, but no more than +0.4 (40% extension that is *1.4).

Examples:

• 0 : no dwell extension at all (neither voltage nor MAP based): Coil Charge Time @13.2 is used. Mainly used to set at fixed pulsewidth for external ignition amplifiers (CDI or smart coils).
• 1 : The recommended value, only voltage based dwell extension (max *2, when voltage is at or lower than 7 Volts).
• 2 : 40% reached at 890 kPa, and 1.5% at 100 kPa.
• 3 : 40% reached at 616 kPa, and 2.2% at 100 kPa.
• 5 : 40% reached at 400 kPa, and 3.6% at 100 kPa.
• 10 : max dwell-extension +40% reached at 234 kPa because (234 kPa - 70 kPa) * 10 /4096 = 0.4. This is a lot of extra charge time! Take care if using a higher setting than this.
• 20 : max dwell-extension +40% reached at 152 kPa because (152 kPa - 70 kPa) * 20 /4096 = 0.4
• values 2..255 : Battery voltage based extension is automatic. Slope of MAP-based dwell-extension is configured with this variable. MAP-based extension is max *1.4 (+40%), while total scaleup (vbattmultiplier * mapmultiplier) is max *2.
• Do not use values higher than 20, as this is likely to overheat/destroy your coils.

Higher value means higher slope (so max dwell extension reached earlier). Take care not to overload the ignition output or the coil (use lower Coil Charge Time @13.2V so you only get extended dwell when really necessary).