It is fascinating to watch the pitstops of Formula 1 where they seem shockingly long if they take three seconds to change out their wheels and tires. This past year the record was 2.0 seconds. Pit stops at the Indy 500 are also amazing to watch as they only have one person per tire (Formula 1 has many) and the impact guns are on hoses and must be dragged out of the way so that the cars can take off and rejoin the track. In the past, NASCAR tire changes were depended upon five lugs to be undone and then the new wheel had fresh set of nuts already stuck on each wheel ready for the impact guns to be quickly tightening them in a circular fashion with a speed that was almost too fast to see. Each tire corner worker would also have spare nuts at hand in case any of them attached to the wheel might come loose. With their next gen cars five lugs are gone as NASCAR has adopted the single center lug design of the above racing formulas.
Speed in the pits is as important as speed on the track and the impact gun it a critical part of the process. United Race Parts booth was an amazing place to stop and visit as they had the premier wheel guns on display. Paoli is the tool of choice for the top teams.
Above is the business end of this race tool. The wheel nut sockets are all custom made out of titanium. If you look closely at the perimeter you see round circular things. What are they? Magnets that pull the socket to the wheel nut and secure it tightly to the socket. Formula 1 wheels have captured center wheel nuts that are part of the wheel and other race series are moving to adopt to that approach. In the mean time, it remains important that the socket has full contact with the single wheel nut.
As you look at the back side of the Paoli gun, you will see that there are two prominent sliding pins that are there to push in either direction so as to change the rotation of the un and socket. The next time you watch an Indy pit stop you will notice that when the corner tire changer undoes their wheel they drop the gun so that the button is pushed into tighten mode as the gun hits the surface of the pit road. When that corner tire changer puts on the replacement tire the gun can be picked up and is already in tighten more. Often the torque on the gun is higher in loosen mode than it is in tighten mode, but still far higher torque than you use on your street car’s lugs.
Above you can see a new addition to the Paoli lineup. Look closely and you can see that it has a battery pack to power it instead of a pressure hose hook-up.
Notice that the there are four round LEDs just behind the red Paoli sticker on the top. The desired torque can be pre-set and the LEDs indicate to the operator when proper torque has been achieved. You will be seeing these new electric guns taking over tire change pit stops in the future.
No matter which of the Paoli guns you choose be prepared to open up your checkbook. The guns sans the socket are in the $20K range and add another $10K for a custom made socket. I’ve been told that Formula 1 teams budget upwards of $200,000+ for their needs of Paoli tire changing guns and sockets for the season.
As they say, the devil’s in the details.
JIM'S GARAGE 
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