Hyper Racer - Copyright © 2009 - Dean Crooke


The Starter Motor Automatic Protection Device has been designed to eliminate the problem of starter motor damage on racing cars fitted with motorcycle engines.

Motor car engine
In a conventional motor vehicle, when the starter button is pushed, the current from the battery is applied to the solenoid, the solenoid engages a lever that pushes out the drive pinion on the starter driveshaft and meshes the pinion with the starter ring gear on the flywheel of the engine. The solenoid also closes high-current contacts for the starter motor, which begins to turn. Once the engine starts, the key-operated switch is opened, a spring in the solenoid assembly pulls the pinion gear away from the ring gear, and the starter motor stops. The starter's pinion is clutched to its driveshaft through an overrunning sprag clutch which permits the pinion to transmit drive in only one direction. In this manner, drive is transmitted through the pinion to the flywheel ring gear, but if the pinion remains engaged (as for example because the operator fails to release the key as soon as the engine starts, or if there is a short and the solenoid remains engaged), the pinion will spin independently of its driveshaft. This prevents the engine driving the starter, for such backdrive would cause the starter to spin so fast as to fly apart.

Motor cycle engine
However a motor cycle engine operates differently in that the drive pinion is constantly engaged with the ring gear and does not disengage when the engine is running. This is fine as long as the engine is running in the forward direction. A problem arises, when the race car fitted with a motor cycle engine, spins on the track and the engine momentarily rotates backwards, damaging the starter motor.

Driver's work around this problem by disengaging the clutch and/or applying the brakes and locking the wheels as they slide backwards. Unfortunately the driver does not always react quickly enough, with the result being that the starter motor disintegrates.

The SMAP Device has been designed to eliminate the problem of starter motor damage by instantly disengaging the clutch when it senses reverse axle rotation.

Hyper PRO Racer
The SMAP Device is available as a bolt on option on the Hyper PRO Racer. Like all motor cycle engined race cars i.e.; Radical, Westfield Clubmans, Aussie Racing Cars etc, the PRO Racer is a fully functional race car without the SMAP Device fitted. However, as many drivers of motor cycle engined race cars have found out, you do not always get to the clutch or on the brakes in time to save the starter motor from destruction. Worse is in store for the corporate rental race car operator that is putting inexperienced drivers into these cars, with the inevitable result that the drivers first spin results in the destruction of the starter motor. With the SMAP Device fitted to the PRO Racer, the corporate operator eliminates this issue from his business.

This is a World First Design and is an exclusive option on the Hyper PRO Racer.

Copyright - Design Registered - Patent Pending