Limiters tricked by illegal device

AS a driver you have probably been left behind as some cowboy cruises past you going 120, 130 or 140km an hour or more.

Chances are they either have a faulty speed limiter or an illegal bypass device that gets around the speed limiter.

The Victorian Police stand at the recent Sandown Heavy Vehicle Safety Drive Day in Melbourne showcased a large range of illegal speed limiting bypass devices.

Senior Sergeant Wayne Cully said many of the devices on display had since been superseded by others and the old whizzers replaced devices such as dog collars.

Snr Sgt Cully said the mechanism that controls speed limiters could be simply altered by the dog collar devices that confuse the limiter and allow the vehicle to go much faster than the 100km/h limit.

“There are a number of ways people used to get around speed limiters and still do it unfortunately,” he said.

“They put devices on because the pulse wheels have so many teeth on them the engine management system counts the amount of teeth as they revolve.

“If a number of teeth are taken out or taped over the ECM thinks ‘oh hang on that's only 14 or 13 teeth I'll have to speed up to find out where the others are and it overrides it that way'.”

He said going over the 100km speed limit was a fairly easy way to tell if a truck had a device or faulty speed limiter.

But he conceded there would be run off going down hill.

“We accept that coming off a hill loaded there will be some run off and that's fine, but when you're back on the flat and moving away either the cruise control or the driver has to bring the truck back to 100 km/h,” he said.