Change visitor typeROTOTEST VPA-RX Chassis Dynamometer - How it works
The obvious difference between a traditional chassis dynamometer and a ROTOTEST® VPA-RX™ is the lack of rollers. By replacing the drive wheels with wheel adapters the dynamometer units are bolted in place, providing a slip-free installation. The dynamometer itself is built around industrial hydraulic pumps, which are mounted in a cradle. The movement of the cradle is limited by a Rototest patented torque measuring system that thanks to its clever design includes all parasitic losses (e.g. bearing friction) resulting in industry-leading accuracy. The absorbing torque is generated by limiting the pumps' output flow using a computer controlled ultra-fast hydraulic valve (patented).

An oil flow from the oil pumps is directed through hydraulically driven fans and then through large oil coolers. The fans produce head wind to cool the vehicle while at the same time ensures a proper operating temperature of the ROTOTEST® dynamometer system. The system is operated from a control cabinet with an intuitive, easy-to-use windows-like user interface.


The ROTOTEST VPA-RX chassis dynamometer is attached directly to the wheel hubs.


The ROTOTEST VPA-RX chassis dynamometer is attached directly to the wheel hubs.
The ROTOTEST® VPA-RX™ chassis dynamometer is attached directly to the wheel hubs.