Swirl, Wake, and Crack Your Cheeks!

One Wake, Two Completely Different Races. Who Else Would Think of Comparing Hungaroring and Thruxton?

At Thruxton and the Hungaroring, drivers complain about the same dirty air - yet the way they interact with it is almost exactly opposite.

In the BTCC at Thruxton, the wake first helps you catch the car ahead - and then makes it harder to negotiate the next fast corner.

In Formula 1 at the Hungaroring, it first makes the sequence of corners harder - while the brief assistance it provides on the straight only partly repays what has already been lost.

The difference is explained not so much by speed itself as by how much of the car’s total grip comes from aerodynamics.

The Speeds Are Closer Than You Might Think

Josh Cook’s Thruxton pole lap was 1:15.219 around the 2.356-mile circuit, giving an average speed of approximately 181.5 km/h.

Lando Norris’s Hungaroring pole lap was 1:17.207 over 4.381 kilometres, corresponding to roughly 204.3 km/h.

The difference in average speed is therefore only about 12.6%. The corresponding average dynamic pressure for the Formula 1 car is approximately 27% higher - certainly not two or three times as high.

More importantly, BTCC cars reach around 160 mph - 257 km/h - on the back section of Thruxton. Through Church, a touring car is therefore travelling at speeds of the same order as a Formula 1 car in many of the Hungaroring’s faster corners.

The main difference is not the air. The air obeys the same laws. The cars are different.

One Wake Contains Two Different Effects

Behind the leading car, two things happen simultaneously.

The first is a deficit in longitudinal air velocity. 

The leading car has already spent some of the flow’s energy overcoming drag and pushing air aside. The following car enters a region in which the air itself is moving more strongly in the same direction as the car, so its relative velocity through the surrounding flow falls.

On a straight, this is beneficial: less drag.

The second effect is turbulence and flow non-uniformity.

The air reaches the front of the following car at different velocities, from different directions and with vortical disturbances.

In a corner, this is harmful: less downforce, and less predictable downforce.

Both effects can be related, approximately, to the dynamic pressure of the incoming airflow, which varies with the square of velocity. If effective airspeed falls by 10%, dynamic pressure falls by approximately 19%.

On the straight, that roughly means: “Drag has fallen - excellent.”

In a corner: “Load on the aerodynamic surfaces has fallen - less excellent.”

But turbulence adds another level of difficulty. It can do more than simply reduce aerodynamic load: it can substantially alter the distribution of that load between the front and rear axles.

Why the Same Loss of Downforce Hurts a Formula 1 Car More

Very crudely, the maximum lateral force can be represented as:

Fy,max ≈ μ(mg + L)

where mg is the mechanical vertical load from the car’s weight and L is aerodynamic downforce.

If some downforce is lost, the relative reduction can be approximated as:

ΔFy / Fy ≈ ΔLa / (mg + La)

Now imagine two hypothetical cars.

On the first, aerodynamics provides only a relatively small part of the total vertical load. Even losing 20% of its downforce therefore reduces the total tyre load by comparatively little.

On the second, downforce represents a major part of the total load. The same 20% aerodynamic loss now has a much larger effect on potential cornering speed.

The first case is closer to a touring car. The second is closer to Formula 1.

That is why loss of clean airflow in a touring car is more likely to be felt as additional understeer or as the need for a small lift.

In a Formula 1 car, it can disrupt the entire intended balance between the front wing, floor and diffuser.

Thruxton: The Wake as an Investment

Much of a Thruxton lap is spent in fifth or sixth gear. The circuit consists of long curves rather than short straights separated by slow corners. Official BTCC material describes it as the championship’s fastest circuit, and because of its high lateral loads and abrasive surface it requires an especially durable hard tyre.

The following driver therefore benefits from the wake not merely on a conventional straight. A car may remain inside the reduced-drag region through a substantial part of a high-speed curve. It requires slightly less power to maintain speed, and the gap gradually closes.

This is particularly valuable before the chicane. A few kilometres per hour gained through the section around Church and Goodwood become extra kinetic energy before the braking zone.

But there is a price to pay for that profit.

What the Touring Car Loses

The front splitter and floor receive poorer-quality airflow. Pressure conditions around the front of the car deteriorate and the aerodynamic balance shifts rearward. The driver needs more steering angle.

On a front-wheel-drive car, this is particularly unpleasant because the front tyre is being asked to do three jobs at once:

• generate lateral force;
• transmit drive;
• compensate for the loss of front aerodynamic load.

Add more steering angle and the tyre begins to slide more heavily. Its surface temperature rises, while the actual increase in cornering response becomes progressively smaller. So at Thruxton it is perfectly possible to close rapidly on another car - and then suddenly discover that you can no longer take Church at the same speed.

The Thruxton Tactic

The ideal sequence looks roughly like this:

1. Use the wake during acceleration and through the first part of the high-speed section.
2. Get close enough to benefit from the reduced drag.
3. Before the most aerodynamically sensitive fast corner, move slightly out of line.
4. Restore cleaner airflow to the front of the car.
5. Re-enter the wake on the exit and prepare the attack before the chicane.

In other words, the driver tries to retain the longitudinal benefit of the wake, while avoiding its lateral penalty.

In touring-car racing this is possible because there is more freedom to vary the racing line, the cars are less aerodynamically sensitive, and they are capable of surviving a little contact or running side by side.

The Hungaroring: The Wake as Debt

The Hungaroring contains very few long sections where reduced drag can be exploited for any meaningful length of time.

After Turns 1 and 2 comes a sequence of corners in which the exit from one immediately determines the entry to the next. Formula 1’s own description of the circuit famously compares it to a kart track, emphasising its linked corner sequences and shortage of straights. The following car therefore pays the aerodynamic penalty through much of the lap and gets its main opportunity to recover that loss only on the start-finish straight.

What the Formula 1 Car Loses

The front wing encounters air with lower total pressure and an altered velocity direction. The floor receives a less stable flow at corner entry.

This is particularly important because the floor is not simply another wing that happens to produce a little less force when disturbed. Its performance depends on maintaining a particular flow structure along its edges, underneath the central section and through the diffuser.

Once that airflow becomes non-uniform, several things can happen simultaneously:

• front-axle load falls;
• the location of the resultant aerodynamic force - the so-called “centre of pressure”, which is not much of a centre in the geometrical sense - shifts;
• the low-pressure region beneath the floor becomes less stable;
• sensitivity to roll and ride height increases.

The driver does not necessarily experience this as constant understeer. Instead, the car may feel acceptable in one corner and then suddenly demand much more steering angle in the next. That forces the tyres - particularly the fronts - to slide.

This is essentially what Norris described while racing behind Piastri. His underlying pace may have been higher, but he could not exploit it while sitting directly in the wake. After Piastri’s second stop, Norris had clear track and, despite running older tyres, began lapping substantially faster than his team-mate on fresher rubber but stuck in traffic.

And it was not only Sainz Jr who mattered there.

But Weren’t the 2026 Formula 1 Cars Supposed to Follow More Closely?

Before the season, FIA single-seater technical director Nikolas Tombazis estimated that a 2026 car following at a distance of roughly 20 metres should retain around 90% of its downforce. For cars from the end of the previous regulatory cycle, he gave a figure of approximately 70%.

The regulations restricted some of the methods previously used to push airflow outward around the wheels and the outer portions of the floor. The front and rear wings also switch into reduced-drag configurations on the straights, while the overtaking aid is now more closely linked to the management of electrical energy.

The FIA therefore expected the new generation to follow other cars much more effectively.

But “retaining 90%” does not mean “being unaffected by the wake”.

Even a 10% loss of aerodynamic load can matter enormously if:

• most of it is lost from the front axle;
• its magnitude changes from corner to corner;
• it arrives with turbulent fluctuations;
• the driver has to compensate by overheating the tyres.

And active drag reduction helps on a straight. It does not restore clean, uniform airflow to the front wing and floor in a corner.

Tyres: Similar Outcome, Different Route

Touring Cars

At Thruxton, the main victim of dirty air is the outside front tyre. The car loses some front load, the driver increases steering angle, and the carcass and tread operate at greater slip angle.

On a front-wheel-drive car, drive torque is added to that burden - demanded in horsepower-sized doses simply to overcome the largest aerodynamic resistance seen anywhere in the season, thanks to the championship’s highest average speeds.

But the hard tyre compound and the relatively modest contribution of aerodynamic load make the process more predictable. The car does not normally lose a huge amount of grip instantaneously. Instead, it begins to turn less effectively and consume its front tyres more rapidly.

Formula 1

At the Hungaroring, the wake can first remove aerodynamic grip and then trigger secondary thermal degradation.

First, the car loses aerodynamic grip. Then the driver compensates with mechanical sliding, overheating the tyre. After that, the car begins losing mechanical grip as well - even if it subsequently returns to clean air.

In other words, dirty air in Formula 1 can leave behind a kind of thermal debt.

Cooling Is Different Too

The wake contains not only turbulent air, but heated air.

In touring cars, reduced airflow through radiators and brake ducts may force the driver to back off slightly, particularly when running in a tightly packed group. But larger air intakes and less extreme packaging generally provide a greater operating margin.

In Formula 1, radiators, brakes, power electronics and battery systems operate inside an extremely tightly packaged car. The temperature of the incoming air affects not only the combustion engine, but also the capability of the electrical system and the cooling of the oil and brakes.

So sometimes a driver drops back from the car ahead not because the tyres are finished, but because one particular temperature has approached its limit.

In Brief

The Main Point

At Thruxton, the wake is rather like a loan: the driver receives speed now, but has to pay some of it back in the next fast corner.

At the Hungaroring, it is more like a tax: the driver pays in lost downforce throughout much of the sector in return for a small rebate on one straight.

That is why at Thruxton you can watch one car close rapidly on another, fall back slightly through Church, and then begin closing again before the chicane. At the Hungaroring, a faster car can spend dozens of laps trapped behind a slower one. Every time the driver tries to get close enough to attack, the dirty air spoils precisely the corners that were supposed to provide the speed needed for the straight.

In touring car racing, the wake more often creates an overtaking opportunity.

In Formula 1 at the Hungaroring, it more often destroys the conditions required to create one.

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