Revealed: McLaren’s clever trick to get around diffuser limits

Formula 1’s new aero rules aimed to cut downforce have been a big challenge for teams this winter as they have thrown everything at trying to recover the losses.

Revealed: McLaren’s clever trick to get around diffuser limits

But while the focus for many outfits has been on the floor area, and some clever ideas have already appeared, McLaren appears to have stolen a march on rivals with a unique diffuser solution instead.

The package of rule changes for 2021 came in three parts – involving new requirements for the floor, the brake ducts and the diffuser.

For the diffuser, which is a powerful tool for harnessing airflow under the car to boost downforce, the FIA has mandated that the height of the dividing strakes between its channels are now 50mm shorter.

While the rule seems quite straightforward, there had been suspicions about McLaren having found a clever solution to the new rules when it was so secretive over this section of the car when it was first revealed.

Read Also:

It took particular care that renders from its launch and the images released from it ‘filming day’ at Silverstone didn’t show off any of the important parts at the rear of the car. 

With teams forced to reveal their definitive 2021 concepts in Bahrain testing, it has emerged that McLaren has indeed done something unique with its diffuser.

It appears to have employed a pretty neat trick that allows it to have two strakes below the theoretical cut line which has been created to reduce their height in the new regulations.

The ‘trick’ is that the aerodynamicists have extended the floor transition rearward to create these lower strakes than should be possible (white arrow).

These taller inboard strakes then gradually extrude upwards and outwards as the diffuser's ceiling expands outwards.

McLaren MCL35 diffuser detail

McLaren MCL35 diffuser detail

Photo by: Giorgio Piola

The expansion of the floor transition area is clear when we compare it to the design that the team used in F1 last season. (see above)

Red Bull Racing RB16B rear detail

Red Bull Racing RB16B rear detail

Photo by: Mark Sutton / Motorsport Images

It is also in contrast to solutions seen at other teams where the strake depth is uniform across the diffuser, as can be seen on the Red Bull.

The McLaren idea is one that will almost certainly be evaluated by other teams to see if there is much of a performance gain there.

But with just two days left of testing, and less than two weeks until the first race, it is unlikely rivals will be able to copy the concept just yet. So it may take some time for rivals to follow suit if it is deemed a good benefit. 

shares
comments

Related video

What we learned from F1's first full race simulations

Previous article

What we learned from F1's first full race simulations

Next article

Hamilton: ‘No point getting worried’ over Mercedes mileage

Hamilton: ‘No point getting worried’ over Mercedes mileage
Load comments

About this article

Series Formula 1
Event Bahrain March testing
Teams McLaren
Author Matt Somerfield
The Barcelona practice times that prove Red Bull has hidden pace Prime

The Barcelona practice times that prove Red Bull has hidden pace

Lewis Hamilton led the way in Friday practice for the 2021 Spanish Grand Prix, but there was one major encouraging sign for Red Bull. However, making good on that gain will require Max Verstappen to avoid repeating a mistake that left him well down the FP2 order...

Formula 1
May 7, 2021
Why McLaren doesn’t doubt Ricciardo can escape his ‘dark’ place Prime

Why McLaren doesn’t doubt Ricciardo can escape his ‘dark’ place

Three points finishes from as many starts represents a decent opening innings on paper, but Daniel Ricciardo has endured a tough start to his McLaren career - only magnified his teammate's excellent form. Yet both he and the team have good reason to expect a turnaround soon.

Formula 1
May 6, 2021
What needs to “change” for Red Bull is ending Verstappen’s errors Prime

What needs to “change” for Red Bull is ending Verstappen’s errors

OPINION: Going up against the dominant force of Mercedes and Lewis Hamilton was always going to demand the best from Red Bull and Max Verstappen. But after making a couple more errors during the Portuguese Grand Prix, the Dutch driver showed there's a small gap he still needs to close in the 2021 Formula 1 title fight.

Formula 1
May 5, 2021
The "subtle" Red Bull upgrades that kept it in the Portugal F1 mix Prime

The "subtle" Red Bull upgrades that kept it in the Portugal F1 mix

Red Bull's Portuguese Grand Prix fortunes were decidedly second best to Mercedes', but the result skews the potential that the team had at Portimao. With a new set of updates, the team looks good going forward into the rest of 2021's spicy F1 competition

Formula 1
May 3, 2021
Portuguese Grand Prix driver ratings Prime

Portuguese Grand Prix driver ratings

The 2021 Portuguese GP will for several drivers go down as a weekend of missed opportunities amid imperfect track conditions that caused struggles with tyre warm-up. But the performances of a select few stood out from the crowd

Formula 1
May 3, 2021
The five key tests Hamilton passed to claim Portugal victory Prime

The five key tests Hamilton passed to claim Portugal victory

Just as he did in 2020, Lewis Hamilton had to come from behind to win the 2021 Portuguese Grand Prix. Only this time there were two rivals he had to pass, among the several challenges he had to overcome, on his way to securing a 97th grand prix victory

Formula 1
May 3, 2021
Imola 1994: Memories from Ayrton Senna’s F1 rivals Prime

Imola 1994: Memories from Ayrton Senna’s F1 rivals

The tragic events of the 1994 San Marino Grand Prix changed Formula 1 forever. Here, 17 of the drivers who took part explain how they coped with the devastating deaths of Roland Ratzenberger and Ayrton Senna.

Formula 1
May 1, 2021
The data that leaves both Red Bull, Mercedes uncertain of supremacy Prime

The data that leaves both Red Bull, Mercedes uncertain of supremacy

Lewis Hamilton topped the crucial FP2 session on Friday as F1 returned to Portugal, but his Mercedes team cannot be sure it has the edge on its Red Bull rivals. As cool temperatures and wind combine with the still-slippery surface to present drivers with quandaries over set-up and tyre warmup, there's still everything to play for come qualifying.

Formula 1
May 1, 2021