Used on Cosworth engines, on several Ford and Lancia cars. We also call this trigger 8+2
All (original) sensors, including the VR/VR trigger can be used. In trigger play dialog this pattern can be generated by l008 type (l as in Lancia).
Use the lancia_cosworth.txt configlet (bottom of primary trigger dialog)
- and set "TDC after the trigger" (eg. to 90 degrees ... Strobing is always nice of course)
- VT might show some fake warnings for this trigger. If you used the configlet, and RPM is fine, neglect them, just take a note in the install log: "used lancia-cosworth configlet => trigger-related warnings neglected, as instructed by ... this URL".
Very similar to 8+1, but we have a second camtooth that is neglected if
- and primary_trigger=fiatstilo is enabled
- (yes, fiatstilo bit originally for InputTrigger/ShortGapTrigger such as fiatstilo, subaru, but those are configured with missing tooth option, so there is no collision)
- note that stilo bit is disabled in secondary trigger
Firmware note: 1.2.26 or newer firmware is needed. (With 1.2.0 and around, it was very hard to start the engine with this trigger setup).
Runs well after startup, and good cranking
Cosworth trigger (4 on crank, 2 on cam) has been included in 1.1.x firmware for quite some time.
Even though it was running well after startup, first implementation had some hard-starting during cranking (initial sync sequence). Therefore several installers grinded one camtooth away and used "8+1" (means 4 crankpulse, 1 campulse): InputTrigger/MultiToothNoneMissing
At least one installer added a 36-1 crankwheel (because grinding away a camtooth is quite some work on this engine).
With the improved initial sync sequence (if the VR signals are otherwise in good shape and bias resistor is sufficient), hard-startup cranking is solved.
Double campulse with 36-1 crankweel
If you use 36-1 (or other missing tooth pattern) with the 2-pulse camsync, see applicable setting in MembersPage/DamirMuha/MagnetMmarelliCamSensor ! (Firmware 1.1.89 or newer)
alternate=03 divider=01 # 4 cyl rpmk=0B rpmk=B8 config11=31 config12=30 softrpm_range=02 # coiltype (bit1=1), lanciacoswort (bit5=1), 8+2 with 4 cyl, primary_trigger=23 secondary_trigger=19 # number of primary trigger teeth for engine period (which is 1 camrot in this case) tooth_wheel=08 trigger_tooth=00 another_trigger_tooth=02 # 0 is fine: crank_minper=00 # 0x168 = 360 = 90 crankdegree (4 pulses per crankrot in the 8+2 Cosworth) tooth_wheel_twidth1=68 tooth_wheel_twidth2=01 # actually not used, just default value, compliance with GenBoard/UnderDevelopment/FirmwareChanges reset_engphase_after=40 ign_tdcdelay=78 ignchmax=03 # neglected values: cam_sync_r_edge_phase=00 cam_sync_f_edge_phase=00 h=01 02 04 08 10 20 40 80 h=00 06 04 02 00 00 00 00 h=00 10 20 30 40 50 60 70
Note that this fires ignch3, ignch2, ignch1, ignch0 in this order. You can connect cyl 1,3,4,2 there respectively, or reconfigure for wasted spark for example ignch2 and ignch3 eg.:
h=20 30 20 30 40 50 60 70
Engine RPM/TDC Sensor - VR type
The crankshaft pulley has 4 identical teeth spaced at precisely 90°. The sensor sends a signal to the module whenever a tooth passes a the sensor. From this signal the module determines engine speed (RPM) and the TDC position of each piston (crankshaft position).
Note that pistons are 180 crankdegrees apart, so half of the pulses do NOT belong to pistons. This means this sensor requires camsync to operate. Not as convenient as a normal Bosch 60-2 or Rover K4-type pattern.
The distributor phase sensor (camsync) - also VR
The distributor is driven by the auxiliary shaft as on the standard ohc engine.
A phase sensor, located opposite a cam having two teeth separated at 90° (camdegrees) to each other, is fitted inside the distributor. At the passing of a tooth the sensor delivers a signal to the ECU. This signal is similar to the signal supplied by an RPM/TDC sensor fitted at the crankshaft pulley.
Generating trigger wav file
- Needs a signalgen 2007-04-15 (or later)
- type: l008 (l as in Lancia'. l008 for normal polarity, L008 for inverted, which effectively makes no difference for this wav) type
- for example RPM sweep from 166 .. 7777, 120 seconds long wav file, sectrig position is 23 (that way sectrig pulses clear primary pulses no matter which edge is selected). max amplitude (1000) for both first tooth, and max (1000) for all the rest teeth as well:
./signalgen l008 166-7777 120 23 1000 1000
Thanx to MembersPage/ZoltanAlmasi for documenting the cosworth trigger.
The signal from the distributor and the RPM/TDC sensor together enable module to identify the phase of each cylinder.
Note: the polarity of both sensors must be investigated. This is simple, but shouldn't be forgotten. And inverted if necessary, considering that the VR input HW senses the 0-crossing falling edge. (internally rising edge is configured when VR is used, since that is the output of the VR chip; but the VR input is always falling edge).
Unfortunately this trigger arrangement is not currently supported by firmware.
- with only 1 campulse, it is supported. Short-dwell ignition transformer (or CDI) is required for high RPM
- Is the crank-pulley special in some way ? Is there a chance it can be swapped for a
- multitooth pulley? (available in junkyard, as a long-lasting part that lives well beyond the engine) - under investigation...
- 2 pulses, 50..90 crankdegrees TDC would also work (grindoff ?) with 1-pulse camsync, but a multitooth is unbeatable.
- Original setup must workable with ECU swap, so grindoff not possible.
- how many engines are planned of this install ? It is possible to add firmware support, but it's not without costs
- I plan to build 3 engine with vems at first, but this engine management system is used by most of cosworth (Sierra Cosworth 3 door, Sierra Cosworth 2wd saloon, Sierra Cosworth 4wd saloon, and big-turbo Escort Cosworth) => contact WebShop