MAY 2020 ISSUE
The 2020 Rolex 24 at Daytona saw the No. 14 Lexus RC F GT3 car undertake 29 pit stops during the race. Those pit stops, all of which saw the mechanics add fuel and change all four tires had one thing in common and that was the use of the pit stop wheel gun – two, in fact, one for each side of the car.
The wheels of the Lexus RC F GT3 car are each retained by a single wheel nut which needs to be tightened quickly, safely, securely and reliably, up to a torque of some 600 ft⋅lbs at every stop. Failure to do this will expose the driver to a wheel potentially working loose and the consequent risk of an accident as a result.
Thus, the pit stop wheel gun is an essential piece of race equipment that needs care and attention throughout its life so as to perform its job time and time again.
Weighing in at over 8 lbs. it is nitrogen powered using a line pressure approaching 300 psi. The wheel nuts on the Lexus RC F GT3 car are handed – the two nuts securing the wheels on the right-hand side of the car have left-handed threads while those on the left-hand side of the car (driver’s side) have right hand threads. The pit stop wheel gun needs to perform two specific functions. The first is to undo the hot wheel nut after each stint of the race and then after the mechanic has changed the direction of rotation of the wheel gun using the sliding plunger on the back side of the gun, removed the old wheel and tire assembly and offered up the new one, it has to tighten the wheel nut up to the required torque setting.
The wheel nut is retained in the wheel gun socket by magnets and this prevents the nut falling out of the socket while the gun is on the ground as the mechanic changes the wheel – all designed to save time and minimize error.
Often taken for granted, the pit stop wheel gun is an invaluable piece of race equipment that the mechanics and driver rely upon to perform time and time again.