The difference in time between the winning car and the second place is often measured in milliseconds. Teams will press home even the slightest advantage to give their drivers a chance to stand on the podium, and pushing the cars is one of the acts which provide a very small incremental advantage.
There are several reasons they push NASCARs in the paddock, the technical areas, and to the start line. The reasons include protecting the clutch, preventing stalling, it helps prevent wheelspin, protecting the drivetrain, noise reduction, preventing engine heat and saving gas, and Symbolism.
It may seem strange why NASCARs are pushed around the paddock, in the pits, and to the start. There are good reasons why this happens, which all hinge around making NASCAR as competitive as possible.
The Main Reasons Why Crews Push The NASCARs
There are several reasons why crews push the race cars in the paddock, the technical areas, and to the start line.
1. Pushing The NASCAR Minimizes Stress On The Clutch
NASCAR runs with surprisingly small lightweight clutches. Many of these cars use smaller clutches than are found on street cars (often half the size).
While this reduces the weight for the race, during slower running in the pit areas, it’s very difficult to gently ease the car out of a standstill.
The only times NASCAR is meant to take off from a standstill are during standing starts and leaving the pit stall. In both instances, it is in race conditions where the normal standard is launched at high revs.
During a pitstop, when the drivetrain is up to race temperature, it is hard on the equipment to start from a dead stop. The combination of a lightweight clutch and a high rev start makes It very easy to fry a clutch just sitting there trying to get moving.
2. It Prevents The NASCAR From Stalling
For the NASCAR series, pushing the car avoids the river stalling the car and decreases the out-lap time as much as possible.
If the driver’s about to stall the NASCAR, a push from three beefy crewmen might be the difference between a hiccup and a full-fledged stall.
The gearbox in a NASCAR is designed for high HP but with lower torque at the driving wheels. It keeps the car running at high speed but does not provide a lot of power accelerating to speed. In a true racing gearbox, 1st gear is not a great starting gear where it is common to have a 2.5/1 ratio.
If the NASCAR does stall, the team can also give it a push so that the driver can “Pop” the clutch to get the engine to refire
3. NASCAR Use A Spool And Stagger Set Up
A conventional car uses a differential to compensate for the inside wheel slowing down and the outside wheel speeding up in a corner.
The term “spool” comes from NASCAR, which uses tire “stagger” instead of a rear differential on oval tracks. It means employing a fixed axle on oval tracks to provide optimal traction.
The easiest way to convert the rear end of a NASCAR to a fixed axle is to use a “spool” that couples the axles. The spool is a rigid axle coupling with the same shape as an empty differential housing.
With both axles being fixed together, the size of the tires on each side of the car must be adjusted to compensate for the fact that the outside wheel is going to turn faster (because it has a greater distance to travel) than the inside wheel (which travels a smaller distance).
With this setup, If the tires grip in the pit box and one side wheel is a larger diameter than the other side, the potential damage to the drivetrain is significant.
Giving the car a push start assistance helps to eliminate this issue.
4. Pushing The NASCAR Minimizes Stress On The Half Shafts
There is a bonus in minimizing drivetrain stress. If the river pits for gas only and doesn’t quite get the tire lit up, you can easily twist driveshafts.
There have been instances when after a refueling stop, with tires that are still hot and have a lot of traction, the driver has dumped the clutch too aggressively and snapped one of the half-shafts because the hot tires had more grip than the axles had strength.
It is not uncommon for a NASCAR team with more than one car with driveshafts that twist at a different rate to the others in the team, even ones with similar mileages.
So, any stress the crew can minimize by pushing the tractor off the pit box is worth the effort.
4. It Helps To Keep The NASCAR Going Straight
Pushing the car to get it going helps reduce wheelspin enabling the driver to keep the car from going sideways when the cutch is dumped and the back tires start spinning.
5. It Reduces The Noise Of A NASCAR In The Pit Lane
If you have ever stood next to a NASCAR, firing up and idling, you will know how loud it is.
Imagine how loud it is standing next to a pack of race cars doing the same thing. It’s fun for a short while, but your hearing will suffer after hours and hours of this. Add to this that many race paddocks are indoors, where the sound echoes.
6. It’s Hard To Get In And Out Of A NASCAR
Getting in and out of a NASCAR takes some great gymnastic skills, and sometimes it is easier just to push it with your arm in the window to steer.
7. It Helps Manage The Heat Of A NASCAR
Every time the NASCAR is started, it generates a lot of heat which is only dissipated when the car is doing what it is designed to do, which is to race at high speeds.
Running the car at slow speeds while the engine is burbling away makes it hot and increases the potential of overheating.
It is not great for the mechanics who must work near the hot exhaust and engine.
8. It Saves Gas
NASCAR is fueled scientifically and with just the right amount of gas to last to the next refueling stop.
In this scenario, every drop counts, and idling along the start line is not fuel-efficient and can eat into reserves.
9. It Protects The NASCAR Tires
Each hard launch will increase tire wear, and if three burly fellows can give it a start, it reduces a small amount of tire wear.
10. Pushing A NASCAR Can Also Be Done For Symbolism
When NASCAR’s only black driver, Bubba Wallace, was threatened with a hangman’s noose hanging in his garage stall, dozens of drivers pushed his car to the front of the field.
All 39 other drivers surrounded Wallace before the race, and their crews joined them in a solidarity march down pit road as they pushed his car.
A NASCAR Driver Can Push His Car
A NASCAR driver is allowed to push his disabled car to the pit road but may not push another car to assist that driver in saving fuel or in maintaining a cautious pace while saving fuel on the racetrack. As always, no assistance is allowed on the final lap.
There are many reasons why a NASCAR is pushed while in the paddock, pits, and, in some cases, to the start line. The teams exercise even the smallest apparent advantage when the difference between a win and a failure is measured in milliseconds.