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Lower Gears Engine RPM Limit
OEM
FORMERLY - LOW GEARS #1 ENGINE RPM LIMIT
Lower Gears Turn Off Speed
OEM
FORMERLY - LOW GEARS #1 TURN OFF SPEED
Intermediate Gears Engine RPM Limit
OEM
FORMERLY - LOW GEARS #2 ENGINE RPM LIMIT
Intermediate Gears Turn Off Speed
OEM
FORMERLY - LOW GEARS #2 TURN OFF SPEED
Description:
Lower Gears Engine RPM Limit and Intermediate Gears
Engine RPM Limit are meant to approximate ideal
progressive shifting. Lower Gear Engine RPM Limiting
should be used in conjunction with Intermediate Gears
Engine RPM Limiting. However, you can choose to use
only Lower Gears Engine RPM Limit if that is best suited
to your operation.
Both Lower and Intermediate Gears RPM Limiting have
“soft” rpm limits. This means if you are in a heavily
loaded condition or starting on an especially steep grade
and do not want to shift until the engine reaches higher
rpm, the limit will not stop you. If not heavily loaded, it
simply slows the acceleration rate of the engine when
you pass the programmed setting, prompting the driver
to shift for the most “normal” operations.
The maximum engine acceleration rate above the Lower
Gears Engine RPM Limit is 33 rpm/sec and 25 rpm/sec
for Intermediate Gears Engine RPM Limiting.
The engine can accelerate all the way to your
programmed Top Engine limit (TEL) when necessary
and will not be noticed by most drivers if properly
programmed to fi t your application.
Once the Lower Gears Engine RPM Limit has been
determined, the Lower Gears Turn Off Speed is selected.
It is the speed at which the Lower Gears Engine RPM
Limit no longer applies but the Intermediate Gears
Engine RPM Limit does. It is selected as the mean
vehicle speed between where the Lower Gears Engine
RPM Limit intersects the line of gear to be limited and
the line of the next highest gear. Next, Intermediate
Gear Engine RPM Limit and Intermediate Gears Turn Off
Speed are selected in much the same way. The values
for all four parameters are automatically calculated
when using Cat
®
Design Pro.
Available:
All electronically controlled on-highway engines
covered in this handbook
Engine/Gear Parameters