Download Dyno DataMite User`s Manual

(C) Performance Trends Inc 2005
Dyno DataMite Analyzer
Chapter 2 Definitions
Finish Engine RPM
Is the high engine RPM at the end of the test, at which you close the throttle to stop the test.
Desired Accel Time, sec
Is the time for the engine to accelerate from the Starting Engine RPM to the Finish Engine RPM. Generally, you want this time
to be from 6 to 12 seconds. If you go quicker than 6 seconds, the data will not be as accurate.
Total Gear Reduction
Is the total gear ratio between the engine and inertia wheel. This should be the Gear Ratio you have entered in the Dyno Specs
menu, and is set to this when you first open this menu.
Current Readings
Click Current Readings to display the screen showing current readings for most sensors. This screen can be very useful for
troubleshooting problems with signals, or for watching the engine through a dyno test, like a tachometer. See Section 2.7 for
more details.
Help
Click on Help for help on this screen.
2.6.1 Torque Arm Torque Measurement
This is the type of dyno most people are used to. The engine’s
crankshaft is connected to an absorber, like a pump, generator,
etc. The power absorber’s outside case can float in bearings. A
torque arm is attached to the absorber case which prevents the
absorber case from turning. The force in this arm is measured,
and then knowing the distance from the center of the absorber out
to the torque arm, torque can be calculated. See Figure 2.23.
If this is your type of dyno, choose Torque Arm as the Torque
Measurement type. The dyno screen now becomes very simple as
shown in Figure 2.24. See Appendix 5 for calibrating a Torque
Arm type of dyno.
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Figure 2.23 Torque Arm Type of Dyno
Absorber impeller or armature connects to engine
Torque = Load x Torque Arm Length
Absorber
Case
Floats in
Bearing
Load is
measured here
as a force or
a pressure.
Torque Arm Length