Haltech E6X Manual Win Version - Manual (Page 105)

E6X Manual
105
B.2.2 Direct Fire Ignition
There are two forms of Direct Fire Ignition:
1) One coil per cylinder (usually mounted on top of the spark plug),
2) Wasted spark; where two cylinders are paired together (cylinders with the
same TDC but on different strokes) and fired together each time one of the
cylinders requires ignition, which means each cylinder has an ignition event
as it approaches TDC compression (the ignition required for that cylinder)
and TDC exhaust (the ignition received for the paired cylinder).
Each method requires the ECU to know how many coils it must drive. Each coil needs its
own ignitor and ECU ignition output. The ECU also need to know the current engine
position, it obtains this from a synchronisation signal known commonly as a “home” signal.
The ECU is capable of driving up to 4 individual channels. This means that engines with
more than 4 cylinders are limited to waste spark ignition. Waste spark ignition systems can
ignite 2 cylinders for each ignition output, so consequently direct fire ignition cannot be used
on engines with more than 8 cylinders.
Note:
Engines with an odd number of cylinders cannot use waste spark ignition since
these engines cannot pair cylinders.
If a 6 or 8 cylinder engine is equipped with a single coil per cylinder these coils can be paired
and driven as a waste spark configuration.
One Coil Per Cylinder Ignition
The ECU is capable of driving up to 4 individual coils in a sequential fashion and will fire its
four ignition outputs as follows:
Ignition
#1
Ignition #2
Ignition #3
Ignition #4
The cycle starts after a synchronisation or home signal is detected. Refer to 4.2.3 Ignition Set-
up Page, p41.
Please note that the type of ignition mode selected will have an effect on the available
Injection modes.
The diagram below shows how the ignition outputs would be allocated for a four-cylinder,
four coil direct fire application.