SuperFlow AutoDyn, Operator'S Manual

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Supplemental Information
Appendix B - Page 214
AppB Test Repeatibility.fm
B.2 The Dynamometer
• Calibrate, calibrate, calibrate!!! Insuring your dyno's torque measurement system is
correctly calibrated is critical to obtaining repeatable results. The Hendrick team
calibrates before and after each test. Other teams calibrate every morning and keep a
log of calibration results. All use precision weights. Also, insure you have loaded
correct calibration values for your fuel and air turbines.
• Keep your dyno in good operating condition and follow the proper maintenance
procedures. Change the absorber oil at least every 60-100 hours of operation with
10w30 synthetic oil (60cc for standard absorber, 120cc for 871 absorber). Keep your
dyno and test cell clean. Preciseness comes from cleanliness!
• Keep spare parts available. SuperFlow recommends a zero-downtime kit consisting of
servo valves, engine speed pickups, water filters and absorber pump seals. Those
parts and a few others are essential to have on hand during crunch time. Contact a
SuperFlow Customer Service Engineer for details and ordering.
• Oil and water temperature management is absolutely essential for repeatability.
SuperFlow sells a pressurized cooling tower and an oil cooling heat exchanger. Invest
in both.
• Fuel system management is also critical. Fuel flow and pressure rates should be
consistent. Fuel temperature must also be maintained to get repeatable BSFC and A/
F ratio numbers. Fuel temp is also critical to power repeatability.
• Air flow measurement is crucial. It provides BSAC and volumetric efficiency numbers.
Make sure your air turbines are calibrated. Send them back to SuperFlow yearly to
have them checked. Keep your calibration numbers handy so you can verify the
proper ones are loaded in your software.
• Buy a mercury barometer to obtain the correct barometric pressure reading for
calibrating the dyno. Correct the reading for temperature and gravity.
B.3 The Operator
• Be smooth and consistent.
• Start every test of record with the same oil and water temperatures.
• Develop appropriate test methodologies and routines specific for your application. For
instance, Hendrick Engines tests from 5400-8700 on open motors and 4900-7300 on
restrictor plate motors. They use 100 RPM accel rates and critically monitor oil and
water temps. Allow the engine to stabilize at an RPM before pressing START to begin
the test.
• Average your test data before attempting to analyze it. The WinDyn software allows
multiple tests to be averaged together. Use a minimum of three tests. Engines simply