Ground effects in F1 are nothing new, but they were largely banned decades ago. We didn’t see ground effects being used again quite so obviously until the introduction of the 2022 cars. This left many fans wondering why F1 banned ground effects in the first place.
F1 banned ground effect cars in the 1980s because the FIA felt that the high cornering speeds were becoming too dangerous. If the ground effect was disturbed, cars would lose so much of their downforce at one time that it just became too risky, and the ground effect was banned for the 1983 season.
The ground effect is a clever concept that was heavily developed in F1 in the 1970s. It’s also quite a complex concept, and in the article below I aim to break it down in a way that is easy to understand, but without losing any of the important detail of this fascinating effect.
Note: An important fact to be aware of from the start is that the ground effect wasn’t completely ‘banned’ and it wasn’t technically ‘reintroduced’ in 2022. It has always been there in some form, just not as obviously (or as hyped by the fans and media) as it is now. I’ll explain more about this in the article below.
What Are Ground Effects In F1?
The ground effect can be broadly defined as the increased lift/downforce a body experiences when close to the ground. It’s not a concept exclusive to F1, and birds and planes make use of the ground effect in the opposite direction to F1 cars. When close to the ground, these bodies experience additional lift and reduced drag, allowing them to accelerate to a speed that let’s them take off.
Note: Downforce can be thought of as lift in the downward direction, and it’s sometimes called ‘negative lift’ for this reason
When Were Ground Effects First Introduced In Formula 1?
Ground effect cars were first used in F1 in the late 1970s. Colin Chapman’s Lotus 79 took the F1 world by storm by being the first car to fully utilize the ground effect, after testing it the year before. The Lotus, with Mario Andretti at the wheel, was driven to championship glory in that season.
But F1 cars have made use of this effect for a lot longer than many people realize, as components on the car like the front wing make use of it, not just the complex tunnels underneath the modern cars. Front wings generate more downforce when they are closer to the ground as a result of the ground effect.
Per my note at the beginning of the article, the ground effect was never truly banned or reintroduced, but the way in which it could be used was changed. So, it may be more accurate to refer to ‘ground effect cars’ rather than ground effect having been banned, as it was the exploitation of the ground effect to its maximum that the FIA outlawed in the 1980s.
The Ground Effect Cars Of The 1970s/1980s
So, how did these ground effect cars of the 1970s and early 1980s work?
In order to create lots of downforce, the underside of the car’s sidepod was shaped like an inverted wing (they did not have Venturi tunnels like today’s cars – more on this later). This shape forced the air under the car to move through a tight space, and this caused the air to speed up.
The faster moving air generated an area of lower pressure. This area of low pressure under the car effectively ‘sucked’ the car to the ground. The closer the car got to the ground, the stronger this effect could be, and therefore the more downforce they could produce.
This creates downforce, but in a different way to how other components of F1 cars do it. Rear wings are perhaps the easiest to consider in terms of how they produce downforce (things like bargeboards are a little more complex), and it creates a useful comparison with the ground effect.
How Rear Wings Generate Downforce
The rear wing of an F1 car generates downforce using Bernoulli’s Principle and the continuity equation. In simple terms, the continuity law says that if airflow hits an object like a wing, the same ‘amount’ of air flows above and below the wing.
But the path the air must take below the wing is longer than the path above the wing (due to the wing’s shape), and the continuity equation also says the amount of air entering at the front of the wing must be equal to the amount of air leaving at the back.
This means the air underneath the wing needs to speed up in order to compensate for the longer distance it travels. This is where Bernoulli’s Principle comes in, which says that faster moving air has lower pressure. Lower pressure under the wing and relatively higher pressure (slower moving air) above the wing creates downforce.
The problem is that wings also create drag, and importantly for the 2022 F1 regulations, a lot of dirty air.
The Problem Of Dirty Air
Dirty air is turbulent air that leaves the back of an F1 car as a result of interacting with the various downforce-generating components on the cars, like front and rear wings, and even the tires (and formerly the complex bargeboards). While the lead car benefits from increased downforce, this dirty air thrown out the back limits the impact of the downforce-creating components on cars behind it, making it harder to follow other cars.
This dirty air is made up of many complex things, from the mushroom-shaped wake at the back to the low energy wakes of air coming off the tires. It’s all essentially air that has lost energy in the process of being used to generate downforce for the lead car. This slower, turbulent air is less useful for creating downforce for the car behind, which makes it hard to follow in corners where downforce is crucial for maintaining grip and high speeds.
Key Fact: F1 cars in the past could lose about 50% of their downforce when following another car, depending on how far back they were
While that’s the main reason F1 cars since 2022 look so different to their predecessors, it’s the element of reduced drag that originally made the ground effect so lucrative for F1 teams in the past. Big wings produce a lot of downforce, allowing for fast cornering. But they also create drag, which is essentially a force working against the direction the car is traveling in.
Reducing Drag
As the rear wings are great at utilizing low pressure areas below them to suck the car to the ground, at high speeds they also leave a low pressure area behind them. This low pressure at the back and higher pressure at the front arrangement at high speeds means the car is constantly battling a kind of ‘suction’ effect trying to pull the car backwards.
This limits top speeds on the straights, so the ideal solution was to limit the sizes of the wings, obviously losing out on downforce, but also minimizing drag. Then, the ground effect could be used to make up the downforce losses, without having to worry too much about drag. This led to some very fast cars!
The ground effect became so effective that more and more teams started using it. The ground effect was great for older cars that were less powerful and lacked downforce from wings and bodywork. However, when the cars became more powerful, and cornering speeds increased rapidly, the issue of safety become more important.
KEY POINTS
• The ground effect is an increase in downforce the closer an F1 car gets to the ground
• The effect has been used in F1 for decades, but to a more limited extent than in the 1970s and early 1980s
• It provides a way of generating downforce without as much drag as some other components produce
Why Were Ground Effects Banned In F1?
Ground effects were banned in F1 because, as the cars began to corner at higher and higher speeds, it became very dangerous when cars suddenly lost the suction effect created by the ground effect tunnels under the car. This could happen relatively easily, causing the car to lose downforce.
Essentially, teams realized that a great way to maximize the ground effect and gain even more downforce was to attach skirts to the sides of the cars. This effectively sealed off the edge of the floor of the car, very close to the ground, meaning the airflow under the car wasn’t able to escape out the sides.
This made the wing shapes underneath extremely effective at producing downforce. However, if the skirts broke, or if the car raised up significantly going over a bump or kerb, the seal would break, causing the air pressure under the car to rapidly increase as the airflow was disturbed and the tunnels lost their effectiveness. This would cause the cars to effectively lose almost all of their downforce instantaneously.
Why Was This Allowed In The First Place?
Back then, the understanding of aerodynamics was not as great as it is today (although it was still impressive of course). This meant teams had to use skirts to seal the floors as there was no other perceived way to do it that would be as efficient, and therefore allow for as high speeds (more on how this isn’t the case in modern F1 cars in the next section).
It was fairly easy for these skirts to get damaged, either through contact with other cars, general wear and tear, or by going too aggressively over the kerbs. If this happened at high speeds, the cars could lose lots of downforce very quickly at critical parts of the track, potentially resulting in very nasty accidents.
When Were Ground Effects Banned In F1?
Ground effect cars were banned in F1 in the form of various other regulation changes, namely a ban on skirts in 1981 (that was later reversed in 1982) and a rule that required all cars to have flat floors from 1983. This didn’t outlaw the ground effect directly, as flat floors could still make use of the ground effect, just not to the same extent as the previous generations of cars could before the bans.
Key Fact: In the years leading up to the introduction of the 2022 regulation changes, F1 cars still generated a lot of their downforce using the underfloor and the ground effect. Some estimates suggest about 50-60% or more of the cars’ downforce came from the underfloor in 2017-2021.
How The Ground Effect Works On 2022 F1 Cars
In 2022, the ground effect made its return to F1 (again, it had been used after the bans in 1983, just not in such an extensive way). It had been almost 40 years since we last saw a car that uses ground effect to such a great extent. However, teams and the FIA have learned from the past, and they designed it to be safer and more effective for 2022 and beyond.
Engineers simply have a much better understanding of aerodynamics now than they did in the 1970s and 1980s, and they know how to safely implement it. Importantly, from 2022 onwards, there won’t be the controversial and dangerous skirts. Instead, teams implement clever aerodynamics to help seal the floors and make it work effectively.
With greater aerodynamic knowledge and simulation software and techniques, teams have been able to seal their Venturi tunnels under the car aerodynamically, rather than using vulnerable skirts. They do this using vortices, which are created by outwash generated by the strakes and/or the underside of the sidepod inlets.
This is a much safer way to seal the underbody of the car, as it cannot be damaged in the same way physical skirts can, only disturbed. This means a sudden loss of lots of downforce is unlikely. But there is still the question of why F1 would bring this effect back in such a large capacity in the first place.
Why Was The Ground Effect Brought Back In 2022?
The ground effect is returning to F1 because overtaking has become increasingly difficult in recent years. The cars have become larger and more focused on producing massive amounts of downforce using large wings and complex bargeboards.
This downforce made the cars faster through the corners, but this caused a wake of dirty air to flow off the back of the car. This dirty air disrupts the downforce of the car behind, causing them to lose grip and become slower when they’re within a few car lengths of the car ahead.
The solution was to get the cars to produce less dirty air in their wake by removing a lot of the excess wings that disrupt the airflow over the car, and to eject it over the cars behind (using components like the beam wing). The intended result is for their to be more ‘clean’ air left for the car behind to use to produce downforce, making following much easier through the corners.
Final Thoughts
F1 banned ground effect cars in the 1980s as the FIA deemed them to be unsafe at that time. When the seal between the cars’ skirts and the track was broken, such as when they went over kerbs or if the skirt broke, the cars lost a massive amount of downforce, and they could easily spin out of control.
Modern F1 cars now use ground effects to a large extent once again, but while major use of the effect was banned decades before it’s ‘reintroduction’ in 2022, the cars had actually been making use of it in seemingly more subtle ways even after the bans, with a lot of their downforce continuing to be generated by the underbody via the ground effect.
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