Haltech E8 - Manual (Page 102)

Haltech E11/E8 Instruction Manual
The height of this map is angle at which the trailing spark trails the leading spark. If a flat map at the
height of 10 degrees is set, then the trailing spark will always fire 10 degrees after the leading spark. The
Rotary Engine Ignition Split Map is a 3D map that allows adjustment depending upon load and engine
speed. See Halwin User Guide section for details on the controls used to tune this map.
Idle Control
BAC Idle Control Tuning
BAC valve idle control is used to hold steady the RPM when off the throttle. This method of controlling
RPM at idle is done by looking at the difference between the target idle RPM and the current RPM and
adjusting the BAC valve’s output duty cycle until the difference is zero.
• BAC Frequency - Frequency that the BAC solenoid will run at.
• Temperature Range - There are two temperature values to be set, a cold temp and a warm temp.
Coolant temperatures below the cold temp value will use target RPM, duty cycle and duty cycle
offsets below it in the table. Coolant temperatures above the warm temp value will use target RPM,
duty cycle and duty cycle offsets below it in the table. Any coolant temperatures between cold and
warm temp will interpolate target RPM, duty cycle and duty cycle offsets between their cold and
warm values.
• Target RPM - The RPM at which the Engine will idle.
• Start Duty Cycle - This is the duty cycle that the BAC valve will default to when the engine RPM is
falling towards the ‘Target RPM’ and before it begins its idle control. This value should cause the
engine to idle at a speed just above the ‘Target RPM’. If this value is too low then the RPM will fall
below the ‘Target RPM’.
• Minimum Duty Cycle - The minimum duty cycle the BAC valve will reach when controlling the idle.
Set so that the engine won’t stall. This acts like a throttle stop.
• Post Start Duty Cycle Offset - On start up, this opens up the BAC valve to help start the engine by
allowing more air. This value is added on to the ‘Start Duty Cycle’. This new calculated value is used
when the ECU is initialized and the engine is not running and also for the first three seconds of the
engine running.
• Air Con RPM Increment - This value is added to the ‘Target RPM’. It is done to handle the extra
load when the air con is turned on. It is taken away again when the air con is turned off.
• Air Con Duty Cycle Increment - This value is added to the ‘Start Duty Cycle'. It is done to handle
the extra load when the air con is turned on. It is taken away again when the air con is turned off.
• Idle Target Dead Band - Used to stop the idle controller from ‘over controlling’ the idle due to the
small fluctuations in RPM when idling. E.g. target RPM = 1000RPM, dead band = 50RPM, therefore
if the engine RPM fall between 950RPM and 1050RPM then the idle controller will ignore any
changes in RPM and considered it to be controlled. (E.g. 15 – 50 RPM).
• Decel RPM Rate - This value helps determine if the RPM is falling or steady when off the throttle.
When the RPM is steady then it is ready to be controlled. If this value is set too low then the
fluctuations of an RPM which is hovering consistently around one point will make the controller think
that the RPM is never steady. If this is set too high then the RPM could be considered steady when it
is still falling. (E.g. 25 – 50 RPM).
• Decel to Idle Control Wait - When the RPM has finished falling and has become steady, idle control
will happen after this period of time.
• On Throttle Duty Cycle - When on throttle and off boost the BAC valve defaults to this duty cycle.
Page: 102 Copyright © Haltech 2008