Ignition (output, ignadv and dwell) page for MembersPage/EricN
Note that trigger is on MembersPage/EricN/Trigger
Even-fire 6-cyl
using 6 LS1 coil near plug ignition transformers
This is what I know so far: 4 wires per coil
- 12v
- ground
- ground to the ecu
- trigger wire
Factory look is eventually the goal, but for now, I want to practice on this engine the same setup that will be in my racecar when it is actually built, then I will revert back to more simplistic setup.
We usually use ignition channel 2 and 5 for these (recent tradition, that assembled ECMs are setup with ign channel 2 and 5 this way unless ECM goes for V8 with COP: very handy when IgnitionPage/TransformerWithAmplifier is to be used), you need 4 more logiclevel channels (for total 6).
MembersPage/MarcellGal/EngineSwap also uses similar logic-level ign setup for IgnitionPage/TransformerWithAmplifier
Ignition sequence
- cyl order 1 5 3 6 2 4
- wiring
- ch00 EC36pin35 goes to cyl 1
- ch01 EC36pin33 goes to cyl 2
- ch02 EC36pin34 goes to cyl 3
- ch03 EC36pin36 goes to cyl 4
- ch04 EC36pin11 goes to cyl 5
- ch05 EC36pin12 goes to cyl 6
The matching channels found on GenBoard/Manual/DigitalOut/Table
(remember h[2] is traversed backwards]
h[2]=03 01 05 02 04 00 00 00
Trigger - for LS1 ignition transformers
I have measured the trigger signal: (originally measured it as dwell but now realize that I can't measure dwell, it is not accessible.
- Trigger signal is a constant 4 volt, logic level signal.
- Trigger time varies.
- Start/Idle 1 ms
- 3000 rpm approx 4 ms
- Full throttle/5500 rpm .55 ms
How to output a logic-level ignition signal
Use the same driver as the original IGBT is driven from, just solder a jumper wire in place of the IGBT (don't solder IGBT for given channels), between the gate and drain the 2 pins closest to the EC36 connector, and use ign_out=70 in your config /Emil
I connected a coil just to see if all works.
While my 2 year old turned my "engine" over (drill on a modified distributer) I would change the dwell in MegaTune while measuring the voltage at the trigger signal with a scope. The voltage "on" time is basically exactly half of what I set it to in MegaTune. Is this normal?? I expected them to be the same.
I assume there is no simple way to vary the trigger "on" time with RPM so I played with the various settings. To get 5.5 ms I set dwell to 11, very violent spark, don't expect the coils or plugs to last that long at that setting. Set it to 1 ms (2 in megatune) and the spark is ok, will jump a gap of about 1/2 inch, didnt push it any further for fear of arcing to the ecu. Set it to 3 ms and the spark "looks" about right.
Old/inaccurate info
This was how I measured it before, measured dwell on the ecu trigger wire, not correct to measure coil dwell.
- With scope on dwell, length is around 59.x degrees at all engine speeds and loads.
- Duty cycle was at about 95%, stayed constant.
Please correct the above, obviously there must be some misunderstanding as 59 degrees is not equal to 95%*120 crankdegrees.
There really are many ways, eg.:
- scope
- soundcard
- DVM in DC voltage mode (20V): duty = measured_voltage / (VBatt - 2.5V). Knowing RPM and duty, you can calculate dwell
- DVM + on VBatt
- (min.600V) diode (eg. ES2J or 1n4007 in GenBoard/VerThree/RescueKit ) used for the same purpose as on TimingLight
- cathode on ignition channel (ECM output that goes to primary)
- diode anode connected to DVM -
- optionally 270 .. 1000 Ohm parallel with the DVM. A LED in series with 270 Ohm is the best, basically same as on TimingLight (except that lower brightness is used for indication than for a real timing-light).