Why do Formula 1 cars spark? F1's sparking cars explained

F1 fans will notice at every grand prix that sparks fly out of all the cars when they hit high speeds along a straight.

It is crucial that every car does this as it actually helps improve performance rather than hinder. So, why do F1 cars sparkle and how does it help the teams?

Why do F1 cars spark?

F1 cars have a plank underneath, which runs from the rear to just before the front wheels. It was introduced by the FIA to reduce under-body aerodynamics - though this is no longer the case due to the introduction of ground-effect cars in 2022 - as well as prevent the car from bottoming out on the straights. 'Bottoming out' occurring when the underbody of an F1 car hits the track surface. 

An F1 plank is made out of Jabroc, which comes from beechwood built in a composite process, with veneers and resin used on each layer.

The sparks on F1 cars come from titanium skid blocks which are embedded within the plank. An F1 skid block exists to prevent the plank from getting damaged, and they protrude out from the plank itself by no more than 3mm. When the car 'bottoms out' the skid blocks hit the ground first, creating a shower of sparks behind the car in the process.

Titanium skid blocks were originally used in the 1980s and 1990s, and were reintroduced to F1 in 2015.

Sebastian Vettel's Aston Martin sparks as it climbs Eau Rouge at Spa

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Does sparking damage the car?

The sparks coming from an F1 car are intended to prevent damage, rather than being a sign of damage.

An F1 car's plank was introduced in 1994 as a safety measure following the fatal crashes of Roland Ratzenberger and Ayrton Senna at that year's San Marino Grand Prix. It protects the car floor when running over a kerb, while ensuring that teams maintain a minimum ride height as too much skid block wear during a grand prix will result in disqualification.

Article 3.5.9 e) of the 2024 F1 technical regulations says: "The thickness of the plank assembly measured normal to the lower surface must be 10mm [plus or minus] 0.2mm and must be uniform when new.

“A minimum thickness of 9mm will be accepted due to wear, and conformity to this provision will be checked at the peripheries of the designated holes."

Michael Schumacher became the first driver to be disqualified because of excessive damage to the skid block, as he lost his victory at the 1994 Belgian GP.

Jarno Trulli also once received a disqualification because of excessive plank wear, as he initially lost his fourth place finish in the 2001 United States GP - but, Jordan successfully appealed the decision. 

Plank wear caused Trulli to be disqualified at Indianapolis in 2001, before he was reinstated on appeal

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Why does it happen on the straights?

F1 cars run at a specific ride height, and are then pushed down into the track by the aerodynamics creating downforce. The car's aerodynamic surfaces are designed in such a way that the air flowing over the car pushes it down, creating downforce and reducing the car’s ride height.

The downforce pushes the car down the most on the straight, as the amount of downforce created by the aerodynamics increases with speed. This helps the cars to take corners quicker, reducing the lap time.

While this helps with lateral – side to side – movement in corners, there’s no lateral movement on the straight. This means the aerodynamics force the car’s ride height lower, making it closer to the ground and thus more likely to make contact with the track as the drivers hit bumps in the track, which in turn means more sparking. It’s also more common at the start of a race, as cars have up to 110kg of fuel on board and are much heavier than at the end of a race.

You will also occasionally see sparks when a car runs over a kerb, as a kerb is typically higher than the track and can make contact with the skid blocks.

Sparking occurs predominantly on straights when aerodynamic forces push the car into the road

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