Barely two years have passed since Ross Brawn, former F1 team owner of Brawn GP, designed and implemented the regulation changes ahead of the 2022 Formula 1 season. His intentions were pretty straightforward; reduce the impact of dirty air to promote closer racing between cars.
However, the seemingly vile factor that has always obstructed nail-biting battles is back, thanks to the constant evolution of the cars. This makes us wonder if dirty air is a blessing or an outright curse for Formula 1. Here’s a detailed explanation of what dirty air is and how it differs from another seemingly similar yet vastly different phenomena: slipstream.
What is Dirty Air in F1?
Dirty air affects cars that closely follow each other around medium—to high-speed corners. Unlike low-speed corners, medium and high-speed corners, like the ones at Yas Marina Circuit, Catalonia de Barcelona, and Hungaroring, are considered low-grip areas.
Now, amid such low grip conditions, cars are forced to rely on their aerodynamics to stay on track, and this is easier for the lead car, with ample energy available from the oncoming air. Undisturbed air seamlessly flows through the car, subsequently offering much-needed grip to maintain stability.
A huge impact for last year’s Monza winner on Sunday
Though his race was over, Charles Leclerc was okay after this crash coming out of Parabolica#ItalianGP 🇮🇹 #F1 pic.twitter.com/gwZbEQfVdT
— Formula 1 (@F1) September 6, 2020
The lead car has now used up all the energy, leaving behind a pair of vortices, commonly known as low total pressure or ‘dirty air’. The airflow is completely disrupted, and the car closely following behind is forced to cope with a sudden loss in downforce.
In other words, the car is no longer stable, and with less energy available, the cooling systems that rely on the undisturbed airflow to maintain optimal temperature begin heating up. This has a direct impact on the engine and brakes, and in most cases, the driver is forced to slow down and reduce the gap to the lead car until the temperatures are back to normal.
What is Slipstream in F1?
Slipstream comes into effect when two cars follow each other down a straight. In this case, the lead car is at a disadvantage solely because it is forced to cope with higher wind resistance. The oncoming air prevents the lead car from maxing out its straight-line speed.
That slipstream tho 👀@ValtteriBottas put a move on Daniil Kvyat as Week 2, Day 1 wound down#F1 #F1Testing pic.twitter.com/p2Xm5FfJVb
— Formula 1 (@F1) February 26, 2020
Meanwhile, it also creates a low-pressure zone for the car behind, meaning the following car has lesser wind resistance, which positively impacts its straight-line speed. The car gets dragged into the low-pressure zone, which is commonly known as ‘Tow’. Eventually, when the car behind is close enough to the lead car, it can pull out of the slipstream to attempt an overtake.
The difference between Dirty Air and Slipstream
There are three major differences between the two phenomena. First, dirty air comes into effect when two cars follow each other closely through a medium-speed or high-speed corner. Meanwhile, slipstream majorly comes into play when two cars follow each other down a straight.
Cleverly done by @ValtteriBottas in Mexico 👀
He uses George Russell’s slipstream to gain an edge at the start of his successful bid to take the DHL Fastest Lap Award 🚀#MexicoGP 🇲🇽 #F1 pic.twitter.com/vC14KVud6n
— Formula 1 (@F1) November 8, 2021
Second, in the case of slipstream, the lead car is at a disadvantage while in dirty air, it’s the following car that suffers the disadvantage. Third, dirty air harms the following car’s aero balance. However, slipstream doesn’t affect the aero balance in any way.
