About Dyno Power Testing

Dynos can pick up minute changes in power during car tuning.

When testing power output levels during car performance tuning, specialists use a piece of equipment called a dynamometer, or dyno. There are two major types of dynos: the chassis dyno and engine dyno.

Chassis Dyno

A chassis dyno measures the engine's ability to lay power to the drive wheels and can be used with the engine still installed in the car. The car's drive wheels are placed on rollers which turn as more and more power is applied, keeping the car in place. Power is measured by the load being applied to the rollers.

Engine Dyno

For an engine dyno, the engine needs to be removed from the car. It is then hooked up to one of several types of machines, most commonly a fluid coupling connected to a pump which measures the engine's ability to do work at any given rpm.

Advantages/Drawbacks

A chassis dyno more closely emulates power in real-world driving conditions because it accounts for power loss through the drivetrain. It does not provide information as exact as an engine dyno, however. The latter is more useful during dedicated engine tuning.

References

• Circle Track: Dyno Tech - Technology Transfer, Part V