Haltech E6X Manual DOS Version - Manual (Page 122)

E6X Manual
122
After recognising the home event, the ECU will locate the first “standard” engine trigger by
the tooth indicated as “Tooth Offset” which can be programmed via the Ignition Set-up page.
To find the remaining “standard” trigger events, the ECU counts a number of teeth equal to
the total teeth in one cam revolution, divided by the number of cylinders.
For Example a 4-cylinder engine with a 24-tooth wheel on the cam and a corresponding home
would have the following setup values:
Trigger Angle: 65° (10° to 100° as required)
Trigger Type: Multi-tooth
Total Teeth: 24
Tooth Offset: 2 (1 to Total Teeth)
With these set-up values, when the home signal occurs the ECU will start counting the trigger
teeth (24-tooth wheel), when it reaches the tooth offset it will operate as a standard trigger.
The position of the remaining triggers is determined by taking the number of teeth in the
trigger wheel (24) divided by the number of cylinders (4). This number (6) is the number of
teeth that is counted between triggers.
In this case the triggers will occur at the following teeth: 2,8,14,20. Each trigger occurs 65°
(Trigger Angle) BTDC of the current cylinder and will perform ignition based on this angle.
Due to the high frequency of multi-tooth signals the maximum Rpm to which the ECU will
operate is 10,500 rpm. This rpm value is based on the above-mentioned 24-tooth trigger.
E.6.2 Motronic Style Triggers
Motronic style triggers are a type of multi-tooth trigger but are distinct in that they use a
missing tooth instead of a separate home signal to synchronise the ECU with engine position.
The motronic wheels supported by the ECU to date are those driven by the crank only and are
limited to wheels with 60 teeth with 2 missing and 36 teeth with 1 missing. The motronic
wheel operates identically to any other multi-tooth wheel with the following exceptions:
Care must be taken when selecting a “Tooth Offset”, if the tooth offset is selected such that it
will cause the missing tooth to be required to perform a trigger, incorrect trigger timing and
poor engine operation will result.
Grey Trigger Teeth
White Home tooth