Advantages of Factory Pro EC997a

Eddy-current brake

Allows steady-state testing, which enables:

True horsepower readings, unaffected by the inertia of the motorcycle's rotating masses. Actual measurement of the torque produced, rather than a calculation based on the force required to accelerate a theoretical given mass. Therefore, a motorcycle with low rotating masses does not falsely show an inflated horsepower number as it might on an inertia dyno.

Use of an integrated exhaust gas analyzer (EGA). Pinpoint accuracy in isolating tuning problems and their causes, as the engine can be held at a desired RPM and throttle position while recording EGA traces. A delay of some inconsistent duration always occurs between the time a sample is produced and when EGA readings stabilize. Steady-state testing, along with a software-based delay compensation, makes this offset irrelevant. Conversely, the use of an EGA becomes unworkable in conjunction with inertia testing.

Variable sweep testing. By controlling the load on a low-inertia roller, acceleration can be tested at any rate from 1 to 50 feet per second per second (fps/s).

Accurate sweep testing. Sweep tests are calibrated with inertial mass values derived from steady-state testing results. Many dynos, especially without the ability to measure horsepower at a steady state, assign some theoretical average inertia value instead.

Low-inertia roller

Allows fast response, which enables:

Torque/horsepower measurement in the steady-state testing mode. The ability of an eddy-current brake to maintain a steady engine RPM depends upon the inertia of the roller. A low-inertia roller requires high-frequency, low-amplitude corrections. Controlling the RPM with a narrow margin of error allows for increased accuracy in measuring horsepower. In contrast, a high-inertia roller forces low-frequency, high-amplitude corrections. These variations in correcting torque directly translate into false horsepower readings.

Minimal wear & tear on engine. During steady-state testing, the target RPM is attained within 3 to 5 seconds. In contrast, a typical high-inertia roller requires 20 to 30 seconds.

Extremely flexible, accurate sweep testing. In combination with an eddy-current brake, the low-inertia roller enables acceleration testing at rates from 1 to 50 fps/s. The detection of minute variations in the rate of acceleration results in very precise readings. The damping provided by a high-inertia roller masks such subtleties. Flexible and accurate sweep testing assists in isolating acceleration flat spots. The effects of the weight of rotating masses, such as wheels, tires, etc., can also be evaluated.

Integrated 5-gas EGA

Measures CO, NOx, O2, HC and CO2.

CO (carbon monoxide) is a tuning gas, which is the most accurate indicator of mixture strength and allows the quick "roughing in" of fuel metering.

O2 (oxygen) is a diagnostic gas that allows for the detection of misfires, leaky exhaust valves, and/or stagger issues (on multi cylinder engines with common exhaust).

With most dynos that use oxygen sensors rather than EGAs, an "air/fuel ratio" is derived from oxygen content. Yet outside of a lab, that relationship is unpredictable. Still, "air/fuel ratio" is often used as a tuning guide, or even as the final arbiter of whether tuning is complete. On the off chance that this target approximates the oxygen content at peak power, such content is easily attained with a suboptimal fuel quantity, offset, and ignition timing.

NOx (oxides of nitrogen) is a tuning gas, which roughly indicates whether the ignition timing should be advanced or retarded. High readings also serve to alert the dyno operator that detonation may be eminent, allowing possible engine damage to be averted.

HC (hydrocarbons) are diagnostic gasses that indicate misfires and/or oil consumption.

CO2 (carbon dioxide) is a diagnostic gas whose readings will only be in range if the other gases are correct. The desired CO2 value is generally only attainable if further changes to overall fuel and ignition-timing settings alone will not yield any more power.


With a skilled operator, an eddy-current brake dyno with a low-inertia roller and 5-gas EGA produces results superior to those of an inertia dyno or a high-inertia-roller-equipped brake dyno with or without O2 sensing.
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