Historian_One
December 16th, 2009, 10:33 AM
(NOTE: Runs with Thrust 2 in 1981 were at Bonneville not Black Rock. Richard Noble achieved a peak speed of 500 mph. The record set by Noble at Black Rock in 1983 was the first official jet World Land Speed Record set on an alkaline playa rather than a salt flat, although Kitty O'Neil had set a woman's record of 512 mph in 1976 at the Alvord dry lake in Oregon. Thrust 2 weighed 8,000 lbs, with 60% of that being carried on the front wheels. Just one front wheel carried more than the entire weight of the car that Art Arfons ran at Bonneville in 1990. Where as Noble did 500 mph at Bonneville with 4-inch wide front wheels carrying 2,400 lbs each (static weight), Mike Charlton's entire jet bike streamliner weighs only 2,100 lbs empty and runs on 8-inch wide wheels. So while Thrust 2 had to go 240 mph before the wheels got "on plane", Mike's bike is probably "on plane" standing still!)
From THRUST 2 - DESIGN OF THE WORLD LAND SPEED RECORD CAR by John Ackroyd, Proceedings of the Institute of Mechanical Engineers, Volume 199
"At approximately 240 mph (390 km/h) the wheels came 'onto the plane' and control improved. Beyond this speed aerodynamic stability was increasingly effective and the car more precisely controllable. It was found that rapid initial acceleration through the low speed stage improved handling and the car ran arrow true up to 480 mph (772 km/h).
The salt surface was softer than expected and as a result the ruts were deeper, meaning that we had to 'consume' track rather than re-use it. The effect of the salt consistency was that below planing speed, a ramp was being pushed ahead of the wheel, reducing the effective castor angle and giving a natural braking action.
All the runs at Black Rock were made with the Mark 2 wheels. These are basically similar to the Mark 1 units but incorporating the lessons of 1981. The braking slots have been eliminated as they are not required. The front wheels were increased in width from 4 in (102 mm) to 6 in (152 mm) to increase bearing area and reduce rut depth, and therefore increase understeer and reduce planing speed."
From THRUST 2 - DESIGN OF THE WORLD LAND SPEED RECORD CAR by John Ackroyd, Proceedings of the Institute of Mechanical Engineers, Volume 199
"At approximately 240 mph (390 km/h) the wheels came 'onto the plane' and control improved. Beyond this speed aerodynamic stability was increasingly effective and the car more precisely controllable. It was found that rapid initial acceleration through the low speed stage improved handling and the car ran arrow true up to 480 mph (772 km/h).
The salt surface was softer than expected and as a result the ruts were deeper, meaning that we had to 'consume' track rather than re-use it. The effect of the salt consistency was that below planing speed, a ramp was being pushed ahead of the wheel, reducing the effective castor angle and giving a natural braking action.
All the runs at Black Rock were made with the Mark 2 wheels. These are basically similar to the Mark 1 units but incorporating the lessons of 1981. The braking slots have been eliminated as they are not required. The front wheels were increased in width from 4 in (102 mm) to 6 in (152 mm) to increase bearing area and reduce rut depth, and therefore increase understeer and reduce planing speed."