Changes by last author:
Added:
| * maximum RPM is: ..... (interesting for ignition hardware peak current) |
| * maximum RPM is: 3500 rpm |
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** Bosch Motorsport 3x2 coilpacks (4 pcs required for one engine)
** could be driven from 6 IGBT-s (IGBT can handle the double current if dwell is set sufficiently - not too high, and peak RPM < 7000 RPM) |
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** Two cylinder heads, each having inner and outer bank of plugs.
** Each bank uses one Bosch Motorsport 3x2 coilpack (4 pcs required for one engine) |
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| * Six outputs required - using four stepper outputs and two logic level outputs |
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** Suitable resistor values on board?. 255 Ohm is suitable to drive one module, but 120-130 Ohm needed to drive 2 modules (that still protects the i259 chip's outputs).
** I would recommend 6 IGBTs and 2 logiclevel outputs with appr 120 Ohm (=510x150-160 Ohm or so) current-limiting than it can be decided later to use logiclevel or power-outputs. It is also posssible to use 4 stepper (with module driving 8 transformers) and 4 IGBT outputs driving 4 transformers (configured in igndualout, that is perfectly valid and correct for a multispark engine like this !), either 4 driving the 4 modules individually (best setup) or possibly 2*2 connected in parallel (yes, connecting low-side switches in parallel is also safe). |
| ** Suitable resistor values on board?. 255 Ohm is suitable to drive one module, but 120-130 Ohm (=510x150-160 Ohm or so) needed to drive 2 modules (that still protects the i259 chip's outputs) |
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Ign output concept proposal:
While using i259 with lower output protecting resistor (in the 120 Ohm range) might work (or a module that does not have stupidly low input resistance), * Marcell would order ignout: 8 powerIGBT (0 logiclevel) * and use stepper-A and Stepper-C outputs with 100 Ohm protection resistors for 2 or 4 external ign-driver modules (4 transformers, 8 sparkplugs), |
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Ignition output hardware configuration 6 IGBTs and 2 logiclevel outputs * It can be decided later to use logiclevel or power-outputs. * Option 1 : 6 outputs required - using 4 stepper outputs and 2 logic level outputs ** This is the method we will try first using external ignition modules to avoid ignition coil current through ECU ground * Option 2 : using 4 stepper outputs (with module driving 8 transformers) and 4 IGBT outputs driving 4 transformers ** configured in igndualout, that is perfectly valid and correct for a multispark engine like this ** either 4 driving the 4 modules individually (best setup) ** or possibly 2*2 connected in parallel (yes, connecting low-side switches in parallel is also safe). * Option 3 : using 6 powerIGBT-s, can be wired with two coils each. ** it is double the current but ok if dwell is set sufficiently - not too high ** must have peak RPM < 7000 RPM (in fact only 3500 rpm). 8 powerIGBT (0 logiclevel) * use stepper-A and Stepper-C outputs with 100 Ohm protection resistors for 2 or 4 external ign-driver modules (4 transformers, 8 sparkplugs), |
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Obvious, but worths to mention:
When wiring, make sure to pair cyls that are 360 crankdegrees apart (not in same phase, especially not the 2 sparkplugs of same cyl !). |
| On this engine every cylinder head has an inner and outer bank, those will be handled and controlled by the same output signals from the ECU. Each wasted spark coil will send spark to the pair of cylinders that are 360 crankdegrees apart. One coil is _not_ wired to the two plugs belonging to the same cylinder, |
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Assuming an I6 with 153624 firing order (to which the big V12 is related), pairs would be:
16 52 34 |
| Each bank is a regular inline 6 cylinder with 153624 firing order (same as this big V12 is related), the pairs are the usual 1+6, 2+5, 3+4 and will use one Bosch 3x2 coilpack each. |