Transmissions are the part of the car that gives the driver control over which gear and, consequently, how much acceleration and max top speed an engine can produce. In engines as powerful as those in NASCAR race cars, the type of primary transmission used matters a tremendous amount.
While automatic transmissions and manual transmissions each have their advantages, the model of transmission racers uses has been finely tuned for optimum racing capacity.
Key Points:
- NASCAR cars use manual transmissions for peak performance, as opposed to traditional automatic transmissions.
- NASCAR cars feature a shift lever and straight-cut gears to reduce shifting into the wrong gear at the wrong time or shifting too slowly.
- A 5-speed sequential gearbox has been introduced, allowing for more frequent upshifting and downshifting during races.
Having driven both manual and automatic cars quite a bit, I can tell you that while the feel of the manual is far superior, the speed and ease of gear changing with an automatic transmission are unparalleled. But NASCAR vehicles are not street cars, and their transmission components are far superior to traditional transmissions.
Read on to discover how NASCAR vehicles have found a happy medium between feel-shifting and rapid, infallible gearbox response.
Does NASCAR Race Manual or Automatic Vehicles?
Since the 1940s, NASCAR has used a manual transmission with no intention of changing that fantastic formula. Although the build and features of the manual gearbox have evolved and been enhanced to reduce shifting into the wrong gear at the wrong time or shifting too slowly, racing cars have always been manual.
Advances like a shift lever and straight-cut gears have been added, but original features, like a reverse gear, are still a part of the vehicle’s makeup.
NASCAR’s 2022 system is still manual even as it becomes more computer and electronically supported. It is unlikely that there will ever be a point in racing sports will drivers will not be the ones to tell the car when to change gears.
However, as the street cars the stock cars are based on increasingly incorporate changes like electric drivetrains, NASCAR too will need to move beyond configurations of the previous generations.
Even though drivers have a steering wheel or floor-mounted shift levers that use sequential shifting, drivers still need to engage the vehicle to change gears. A clutch pedal must be engaged to switch gears, but the driver no longer has to find the right gear in the manual gearbox, making it faster but essentially still a manual operation.
The end of the H-pattern manual gearbox led to the Sequential gearbox origins found in NextGen NASCAR vehicles. Both of these gearbox configurations are manual and not automatic gearboxes, but the way they work represents a drastic change in NASCAR transmission builds.
The transmission is one of the most regulated aspects of NASCAR official’s rules, and a change like this will give engine builders tons of new techniques to try and get included in the racing league’s regular rules.
NASCAR Transmission System
A transmission takes torque from the engine and transfers it to the rear axle so that the wheels and engine speeds match. NASCAR racers can feel when the two are running in perfect harmony and choose to shift up or down at that time to simulate what an automatic transmission does with the control of a manual gearbox.
This is an important part of stock car racing as there are no RPM gauges for racers to look at, and shifting too early or late will dramatically impact the performance in the race. Racers have an intimate knowledge of how their transmissions work, and below are some of the main components they rely on.
| Components | Function | Location |
| Transmission | Allows wheels and engine to catch up to each other and run synchronized | The main components are seated in the engine bay, but various parts are found throughout the cockpit and axials as well |
| Gearbox | Lets driver select which gear they will go to next to speed up or slow down | Under the gear shifter on the right-hand side of the driver |
| Clutch Pedal | Makes it easier for the driver to switch to another gear and tells the transmission to release and not generate power | Furtherest pedal to the left |
| Rear-Mounted Transaxle | Provides the power from the engine to the wheels | The top of the middle of the rear axle and near the rear wheels |
How Does a NASCAR Transmission Work?
A transmission provides the correct gear ratio to allow the engine and wheels to match the speed. When this happens, the car is running at peak performance. As the racer’s speed increases, they will shift up to 4th gear, where they will stay for most of the race.
The introduction of a 5-speed sequential gearbox has made up and downshifting more frequently possible over the limited configuration of the traditional four-speed gearbox.
During the race, drivers need to shift up or down using rev-matching, where the speed of the wheels and the speed of the engine (RPM) is the same. Because there is no gauge for this other than an experienced driver’s intuition knowing the speeds that correspond to the engine revolutions per minute can be vital to winning the race.
To even the playing field and reduce the need to engage the foot clutch pedal every time a driver wants to change gears, straight-cut gears where teeth face outward were instituted. This is an improved 4-speed manual transmission over the helical gear shape of road cars which requires a heavy engagement of the clutch pedal to release the shifter and make changing gears possible without grinding.
Decreases in the axial load on stock cars make it easier for drivers to shift without engaging the clutch pedal. The introduction of levels takes it one step further, negating the need to select the correct gear and only having to worry about the next gear.
Now the clutch is reserved for starting races without stalling and going into reverse.
Will NASCAR Next-Gen Cars Change Transmissions?
in 2022 the cars switched from the traditional four-speed H-pattern gearbox to a sequential 5-speed which changed things for racers, pit crews, and engine builders drastically. A 5-speed gearbox, sequential transmission, and a lever attached to the steering wheel for shifting up or down are the main components of the new transmission system.
The transaxial has been developed to run the current NASCAR steel driveshaft but also has the capacity to run future hybrid and electric drivetrains for regenerative braking and other electronic-assisted modernizations found in high-performance street cars.
What Pedals Does NASCAR Have?
Like a standard manual street car, you will find three pedals by a NASCAR driver’s feet. The same pedals we are familiar with, the brake, gas, and clutch, are used by drivers as they reach speeds of 200 MPH for 500+ mile races.
Brake
A brake is used to slow down for corners or stop the car in cases of obstructions or to pull into the pit stop. The speed of the cars means brakes need to be extra powerful in case sudden stops are needed. Racers rely more on shifting to the right gear for turns and use brakes in a strategic manner to block or slow down other vehicles when needed.
Accelerator
This makes the car go fast and fires the V8 600+ HP engines to propel the car forward. Naturally, this is the racer’s best friend. If possible, a heavy foot on the accelerator for most of the race is what a racer strives for on traditional ovals and how they win the gold.
Clutch
This pedal is important, and without it, drivers would have a hard time controlling the transmission. Even though straight-cut gears and other adjustments have been made to make clutch pedals less critical during the race shifting, it is still needed at the stop and start of races.
The sequential shifter system in NextGen NASCAR vehicles relies on the clutch to be engaged before shifting to the next gear is possible. Clutch pedals control the manual transmission NASCAR cars use.
