
Output Wiring
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suppression techniques outlined earlier are particularly important. All wasted spark systems
should use ‘Resistive Spark Plugs’ if the engine does not currently use them.
One igniter channel is required for each dual post coil.
Single Post Coils
It is possible to run an engine that has a single coil per cylinder in wasted spark
configuration. This is often done when there is not enough ignition drives to control each
coil individually. In this case two coils are fired at the same time.
Each coil must be wired to a single igniter channel. It will be necessary to split the wiring
from the each ECU ignition output to go to the input of two igniter channels.
IMPORTANT!
When running a wasted spark arrangement with a single coil per
cylinder, each coil must be wired to an individual ignition channel.
DO NOT wire the output of one igniter channel to two coils. This will
result in very low spark energy and erratic engine running.
Wasted Spark Ignition Wiring
To ensure each ignition drive is matched to the correct cylinder, the firing sequence will
need to be determined. Note this option is only possible when the engine has an even
number of cylinders. When using a wasted spark arrangement, an ignition drive will fire
cylinder pairs that are 360° apart in the firing order.
·
Ignition Drive 1 always needs to be connected to cylinder number 1 and its
corresponding cylinder (360° apart in the firing order).
·
Ignition Drive 2 should be connected to the next cylinder in the firing order and its
corresponding cylinder (360° apart in the firing order).
·
If more cylinders exist (6, 8, 10 & 12 cylinder engines) then the pattern should be
continued. For example Ignition Drive 3 fires the third cylinder in the firing order and
its corresponding cylinder.
Use the following table to determine coil ignition wiring for wasted spark applications. Write
the engines firing order in the column on the left.
Write Firing Order Below
Number of Cylinders
2
4
6
8
1
Ign 1
Ign 1
Ign 1
Ign 1
Ign 2
Ign 2
Ign 2
Ign 2
Ign 1
Ign 3
Ign 3
Ign 2
Ign 1
Ign 4
Ign 2
Ign 1
Ign 3
Ign 2
Ign 3
Ign 4
Wasted spark Ignition Wiring
Example - Wasted spark set-up for a 4 cylinder engine with 1-3-4-2 firing order.