Few aspects of racing are less understood than the hydraulics used in F1. Not part of the equation until 1983, F1’s multiple hydraulics systems have become critical to teams’ success. Understanding how each F1 hydraulic system works is key to understanding how F1 racing works.
F1 hydraulics control multiple systems that let the vehicle perform at the level it does, even under the most adverse racing conditions. Hydraulics are used to control the brakes on an F1 car, along with power steering, transmission use and the clutch as well. Even DRS uses hydraulics to work.
Because hydraulics are used in so many key systems within an F1 car, it’s vital that they perform as expected, and hydraulic issues are common causes of cars retiring mid-race. Below, we go into more detail about how the hydraulics systems of an F1 car work.
How F1 Hydraulics Work
The first step in understanding hydraulics is to make a key distinction between “hydraulic” systems and “pneumatic” systems. The two are often confused and both play a role in an F1 car, but those roles are very different.
Hydraulics are run by liquid fluids (gases can be fluids as well). The fluid (oil, water, etc.) is unable to be fully compressed, which builds pressure when compression is attempted. That pressure performs specific tasks related to the operation of whatever machine the hydraulics are hooked into.
With hydraulics, gas is unwanted because it can be compressed, which will reduce the overall pressure able to be created in the hydraulic system, and therefore the effectiveness and reliability of the hydraulic system. Hydraulic systems on an F1 car control many different functions and parts, including:
- Turbo waste gate
- Air inlet variable valve
- Drag Reduction System (DRS)
Since the introduction of hydraulic systems in F1 in 1983, teams have endeavored to add hydraulic control everywhere possible. The advent of Electronic Control Units (ECU) in the early eighties meant that hydraulics could precisely control several major components of the car to keep the racing as smooth as possible.
How F1 Hydraulics Work
- The control system is managed by valves and oil pressure
- The ECU issues data that the valves translate to modify hydraulic pressure for various functions where it is needed
- Pressure is generated by a piston inside a cylinder
- Pipework and manifolds dispersed throughout the car direct pressurized fluid to servo-valves and actuators
- Once the fluid has done its job it is returned to its original position using pressure and gravity
High fluid pressure is needed to operate the various hydraulic systems. A special pump is attached to the engine and it pushes fluid to ensure the pressure level remains the same. The pressure required can be in excess of 200-250 bar, or 2,900-3,600 psi.
The development and adoption of hydraulics resulted in several benefits to drivers:
- The clutch and shifting gears could be controlled by paddles very easily and reliably
- Differentials could be configured in real time to give the driver more control over their driving experience
- Power steering could be used
- DRS could be used to promote overtaking
Pneumatics are also fluid actuated, but the fluid does not have to be incompressible. Gasses, such as nitrogen or air, can be used to perform these duties. Pneumatic equipment or parts usually function with springs, valves, and occasionally floats.
A Cam System
The “poppet” valves in an F1 engine are an example of a pneumatic valve. These are used in all 4-stroke engines and are managed by a “cam” system. Because they tend to be simple, pneumatic systems are less expensive, lightweight and easy to control (outside of timing on the cam shaft).
The reason more pneumatic devices or systems are not used in F1 comes down to consistency and timing. Hydraulic processes and valves are more easily tuned and accurately timed. Pneumatic pressure is not sustainable in and of itself and begins degrading as soon as it is implemented.
Additionally, pneumatic pressure is difficult to time, meaning the cam shaft must be tinkered with to get the type of timing F1 needs.
Key F1 Hydraulic Systems
The key systems in an F1 car that are controlled by hydraulics include:
- Brake by Wire
- Reverse gear
- Power steering
A differential delivers different torque to each wheel it is configured to manage. A hydraulic differential lets teams fine-tune how much differential is utilized at various points on the track. This can give the driver maximum traction through and out of corners, as the power is more optimally provided to each wheel.
Brake By Wire
F1’s brake by wire system was introduced in 2014 and it utilizes the Engine Recovery System (ERS) to help stop the rear wheels when a driver presses the brake pedal. Because only a limited amount of energy can be harvested from the rear brakes through the MGU-K, it’s vital that the braking always feels the same to the driver even when no energy is being harvested.
Brake by wire helps achieve this, as the hydraulic system connected to the ECU ensures that, no matter how the rear tires are being slowed, be it via brake pads, engine braking or via the MGU-K, the driver has consistent feel of the brakes when they press the left pedal. This makes sure they can drive safely and effectively, without worrying about their braking power fluctuating.
Reverse, Clutch & Throttle
These systems also use hydraulics to function effectively. By regulating pressure and controlling gears and valves, hydraulics help F1 vehicles shift gears, move forward, and even use reverse.
F1 cars also use hydraulics for their power steering. Because of the intense loads and G-forces F1 drivers feel during cornering as a result of their high speeds, power steering is used as otherwise the drivers would struggle to turn the car safely. Hydraulic power steering basically makes it much easier to turn the wheels, even under the immense loads cornering puts them through.
The Drag Reduction System helps cars overtake in clearly defined DRS zones, as long as they are within a second of the car in front at the detection point. DRS opens a flap on the rear wing of the car that reduces drag, giving the driver a speed advantage over the car in front to promote overtaking. DRS is activated by a button on the steering wheel, and hydraulics are used to open the flap.
What Is F1 Hydraulic Fluid Made Of?
F1 hydraulic fluid is not much different from regular brake fluid, albeit dyed a different color to help identify leaks. Like standard hydraulic fluid, it’s derived from a mineral oil based-stock. Other base stocks are also used because they’re fire resistant and can function at high temperatures.
These other stocks include:
- Glycol ethers
- Organophosphate ester
- Propylene glycol
- Silicon oils
In addition, hydraulic fluids contain oils, butanol, adipates (bis(2ethylhexy adipate,) polyalkylene glycols, silicones, hydrocarbons and anti-corrosion and erosion inhibitors. F1 has also experimented with environmentally friendly ingredients in their efforts to make their cars carbon neutral.
Why Do F1 Cars Sometimes Leak Hydraulic Fluid?
If an F1 car is leaking hydraulic fluid, it is usually because of one or a combination of several reasons:
- The car is not properly maintained or set up
- Pressure buildup causes a hose or seal to rupture
- The hydraulic system was damaged in a crash
- Other parts failed causing ruptures in the system
In most cases, if a hydraulic system failure occurs on an F1 car, handling, braking, and accelerating become severely impacted. Because of the risk of damage to other components, F1 cars are usually retired if they have hydraulic issues.
Do F1 Cars Use Hydraulic Brakes?
F1 cars do use hydraulic brakes, although they also utilize a system called brake by wire. This allows the rear wheels to be slowed down by a combination of the brake pads, engine braking, and the hybrid system, all without causing any inconsistencies in terms of what the driver feels.
The front braking system of an F1 car functions like any other vehicle, including relying on hydraulics to activate the various components needed to slow the front wheels down. This means that, when the driver presses the brake pedal, hydraulic systems are used to press the brake pads into the discs. However, the rear brakes also utilize a complex system known as brake by wire.
It uses the ERS to help slow the rear wheels, along with engine braking, based on calculations performed by the ECU. When activated, the MGU-K collects energy from the rear brakes and stores it in the battery. When the maximum amount of energy has been stored, either from that lap or as a result of the battery capacity being full, the ECU switches to engine braking and traditional braking.
The ECU’s capabilities mean that all of this can happen without any input from the driver or the team. This ensures that, when the driver presses the brake pedal, they get consistent and reliable braking force at the rear wheels, with no jumps or drops in braking force as the ECU switches between harvesting, engine braking and traditional braking.
Do F1 Cars Have Hydraulic Suspensions?
F1 cars do not have fully hydraulic suspension systems, but they do contain dampers that are hydraulic. Other parts of an F1 suspension system, such as springs, push rods and pull rods may not be directly hydraulic themselves, but the overall system benefits from hydraulics.
Every suspension system serves two purposes: connect the vehicle body to the wheels and improve handling and comfort by absorbing the impacts of the track surface. On a road vehicle, the main goal of the suspension system is to provide a comfortable ride. On an F1 car, it’s all about performance.
F1 cars are not very comfortable rides. Drivers feel every crevice, bump, divot and crack on the racing surface. The suspension helps provide the driver with maximum performance, by being set up in a way according to that specific track and the preferred driving style of the driver.
F1 suspension must deal with another aspect that road vehicles do not: extreme downforce. F1 cars are designed so that the faster they go, the more downforce they generate. This means the suspension system is constantly trying to raise the car up, while the downforce is pushing it into the ground.
That is where “platform control” comes in. Platform control is the ability of an F1 car to manage the pitch and ride height of the car. Both affect the ability of the aerodynamic features of an F1 car to perform correctly. Pitch is balance across the vehicle while ride height is the distance between the floor of the car and the track surface.
An F1 car’s suspension system holds the car at the desired ride height when under downforce load and offsets any shifts in balance in the vehicle. This lets the team preset the vehicle to attain a specific height to maximize aerodynamic features while providing enough downforce to keep the vehicle pinned to the track.
Three Suspension Elements
This involves the suspension elements that are inside the vehicle that you do not see. It utilizes dampers, rockers, springs, torsion bars and anti-roll bars. Of those, dampers are hydraulically managed.
The most common damper on an F1 vehicle is a hydraulic piston that absorbs energy from the suspension. Dampers on an F1 car perform key roles:
- They absorb energy from the chassis
- They transfer energy by virtue of extremely tight calibration, making them very difficult to activate (meaning the load must reach a certain level before activation)
- They ensure a smooth ride, particularly on bumpy tracks and over kerbs that could affect the handling of the car
The outboard suspension involves the elements that are built onto the exterior of the vehicle but are positioned to avoid direct airflow. Outboard suspension parts include uprights, axles and wheel bearings. None of these suspension elements are hydraulic, but they all work as part of one large system.
These are the parts that are exposed and are not hidden under the car. These include wishbones, pull rods, push rods, and track rods.
Are F1 Suspension Systems Hydraulic?
If the definition of a hydraulic suspension is that the entire system must be hydraulic, then, no, F1 suspensions are not hydraulic. If the definition is that a hydraulic suspension must have at least one hydraulic component, then the damper qualifies, and this means F1 suspension systems are partly hydraulic.
The hydraulics of an F1 car are responsible for various systems, including the use of the clutch, brakes, and throttle, along with power steering, DRS, and many important other components. F1 hydraulics were first introduced in 1983 and have since become an essential part of these cars.