40
32.4 Spark
Figure 92
Figure 93
All Holley base tunes contain timing curves that will provide adequate engine operation, however the ignition timing at idle, cruise, and
wide open throttle can be adjusted independently from each other to compensate for different engine combinations and geographical and
climate extremes.
The following are typical values for each:
Idle Timing
– 18-34 degrees is typically used at idle. The larger the camshaft, the more timing is usually used.
Cruise Timing
– 32-48 degrees is typically used when cruising for optimal fuel economy.
Wide Open Throttle Timing (WOT)
– LSx applications typically don’t use more than 28 degrees at WOT. Older V8 engines are
usually between 32-38 degrees.
NOTE:
Too much timing can cause pre-ignition that can damage an engine. Be cautious when tuning.
NOTE:
The actual timing between IDLE, CRUISE, and WOT is blended together automatically. Consequently, the timing you see on
the MONITOR screen, may not be ex
actly what you set for these settings. Changing these settings raises or lowers the “curve”
of that specific area.
32.5 Transmission
NOTE:
Caution must be used when modifying transmission parameters. Lowering line pressures too much can cause rapid
wear and damage to the transmission. The base calibrations provided should provide a safe base calibration. If the
transmission has very soft shifts or seems to slip, immediately stop to diagnose whether the problem is due to tuning
or mechanical issues.
Selecting TRANSMISSION brings up the following menu. There are five areas you can modify; SHIFTS, WOT SHIFTS, TCC PARAMS,
TCC (UN)LOCK, and LINE PRESSURE. These are reviewed below.
32.5.1 Shifts
Each Up-shift and Down-shift can be completely config
ured by selecting ‘Shifts’ from the transmission menu. Refer to section 18.1
(Making Adjustments) of this document for instructions on how to modify these curves.
Upshift/Downshift Tuning Notes:
All Upshift points must occur at a higher speed than downshift. The touchscreen will give a warning and not allow this to occur if
requested.
Although it can be programmed with the handheld, the ECU won’t allow a downshift to occur if it will over-rev the past the MAXIMUM
RPM in the SYSTEM>TRANSMISSION>TRANS SETUP area.
Summary of Contents for 550-407
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