Rake Angle – Unusual Solutions to Usual Problems.

Rake Angle – Unusual Solutions to Usual Problems.

The rake Angle of an F1 car is the amount of angle that the rear of the car is with the front of the car. In this section, we explain how teams use unusual solutions to usual problems.

History Lesson

Before the Aerodynamic revolution of the F1 cars, Lotus was the first to pioneer the ground effect. Especially Lotus 78 of 1977. The idea of using the underbody of the car to create a negative effect and effectively suck the car to the ground has been exploited.

Rake Angle - Unusual Solutions to Usual Problems.
Cars with Skirts : Credit F1.com

After much deliberation, these physical side skirts are banned from F1 and teams have been told to achieve it using aerodynamics. This is when the Aerodynamic revolution in F1 came through. Redbull is the Pioneer of the rake angle concept. Adrian Newey, the pioneer F1 designer was one of the early adopters of this concept. This design took Redbull to 4 Straight world championships.

Mercedes meanwhile stuck with the low rake angle and during the Hybrid era of 2014 the power of the engine caused the high rake cars to have a unstable rear end. Remember the twitchy and undrivable car of the Redbull in 2019. No amount of technical mitigation was able to rectify the issue.

Regulations in 2021

As the new technical regulations of 2021 came into play FIA states that the whole floor must now be solid – while the floors will also feature triangular cutaways at their rear, reducing the downforce-generating surface area on cars further. This came about as a result of the decision to delay the introduction of sweeping new Technical Regulations – which would have included a move from 13-inch to 18-inch Pirelli tires – from 2021 to 2022.

This rule change particularly favored the cars with high rake angles as it gives a clear path for the airflow. But initially, it was thought that the high rake angle cars would suffer as the floor changes will make an even more unstable rear end. But neither of them was true.

Rake Angle - Unusual Solutions to Usual Problems.
Rake Angle - Unusual Solutions to Usual Problems.
The top image shows the current spec floor, the second image shows the trimming required in this area for 2021

High Rake vs Low Rake.

High Rake angle on the car is when the rear of the car is higher than the fronts. Similarly a Low Rake angle the rear of the car is still higher than the front but not as much as the former.

Rake Angle - Unusual Solutions to Usual Problems.
Comparison of Rake Angle

The high-rake angle car is effectively angled forward, and in theory, this greatly boosts the power of the floor. The incoming air is compressed beneath the front wing, creating a powerful high-pressure zone. This causes the air to rush and expand into this space, thus accelerating the air and working the diffuser harder. This theoretically creates a higher peak downforce.

The lower rake angle, on the other hand, the gap is much lower, and thus they require a much longer wheelbase and floor. They are forced to compensate through an increase in floor plan size. That why Mercedes is longer than any other car on the grid. The Rake Angle of the car can’t be increased or decreased as per wish as this has a drastic aerodynamic effect on many parts associated with it. It changes the rear brake cooling and a whole host of components.

Has Mercedes Fixed it?

Rake Angle - Unusual Solutions to Usual Problems.
Mercedes’ 2020 floor vs Mercedes’ 2021 floor. Credits: Daimler.

Mercedes predicted this problem in 2021 regulations and has increased the rake height as much as they can without affecting the aerodynamics of the car. Mercedes have sorted out the problem but playing the sticky up bits on the floor of the car and by simplifying the diffuser to be more effective.

image 9
Winglets on the Floor of Mercedes: Source Autosport

It also changed the barge boards and making changes to the front end of the car. Remember the front wing coming alive it is for the same thing. But this has also lead to a more unpredictable car to drive. This might be one of the reasons why the setup changes are required for the car for slow corner races like Baku and Monaco. Redbull’s performance cannot be linked to the rake angle alone. It has mended and mended and perfected the rear of the car which is particularly unstable in the high rake angle cars.

As the season progresses it will be clear how the changes are affecting the top two teams in different circuits across the calendar.

Share

One thought on “Rake Angle – Unusual Solutions to Usual Problems.

Leave a Reply

Your email address will not be published.