The 7 post shaker is a piece of test equipment used to perform technical analysis on race cars.
Vehicle designers use the results of the testing on the 7 post shaker to adjust spring rates, shock valving and steering ratio to best suit conditions of a specific emulated track.
The 7 post applies lift, downforce, road irregularity forces and load transfer due to braking, acceleration and cornering.
[1] The very basic parameters that need to be initialized are the vertical input forces to the vehicle from the road surface.
The drivers and engineers want to look at how the car reacts to specific tracks, as the car will respond differently at the tri oval at Talladega Superspeedway where speeds can approach 320 kilometres per hour (200 mph) than Bristol Motor Speedway where the corners are banked 24 to 30 degrees.
Once the unit is started transducers in the form of accelerometers and strain gauges, convert the mechanical movement of the vehicle into an electrical signal.
When testing on the 7 post shaker, all variables are inter-related and can be analyzed while the effects of the actual installation can be quantified.