Engine Dynamometers
Engine dynamometers, or "engine dynos," measure torque or revolutions per minute (RPMs) directly from an engine's crankshaft or flywheel. This data gives information about the engine's horsepower.
Because engine dynamometers can be used to test engines separately from vehicles, they are widely used by automobile manufacturers, engine rebuilders, and producers of high-performance vehicles such as race cars. Engine dynamometers do not account for engine losses in the drivetrain, as a chassis dynamometer would. Engine dynamometer tests also tend to produce more accurate and repeatable results.
While engine dynamometers operate on basic principles, a good engine dynamometer is the end result of a great deal of sophisticated engineering. An engine dynamometer must be able to withstand high-frequency vibrations, produce accurate and repeatable results, and be simple to use.