---
title: "McLaren: F1 rivals could copy diffuser design within first few races"
canonical: "https://readmotorsport.com/2021/03/15/mclaren-f1-rivals-could-copy-diffuser-design-within-first-few-races/"
type: "post"
language: "en-GB"
author: "Hamilton Lyndon-Griffiths"
section: "F1 News"
published: "2021-03-15T14:30:45Z"
modified: "2021-03-15T14:30:47Z"
---

# McLaren: F1 rivals could copy diffuser design within first few races

McLaren is a “bit surprised” its diffuser design to claw back downforce lost by the new aero rules hasn’t been adopted by other Formula 1 teams.

During pre-season testing in Bahrain it became apparent McLaren had come up with a unique concept to limit the loss of downforce from the new regulations.

The diffuser is part of the sea of changes to the aero rules for 2021 and has been trimmed by 50mm, but McLaren has managed to find a way around the restrictions.

The Woking-based outfit has extended the floor transition in the central area that isn’t affected by the limitations, allowing it to run deeper fins.

McLaren technical director James Key is clear the design does not exploit a loophole in the regulations, labelling it a “straightforward” incorporation.

“It is a normal design idea, and actually I think we are a bit surprised that maybe we’re the only team with that,” explained Key, as quoted by Motorsport.com.

“It’s just one feature of many in an area which changed for this year. You’ve got a certain regulation of a continuous surface in that area within the Y250 position, either side of the centreline of the car. Those little vortex generators down there which you see as well on pretty much every car now, these little aluminium or carbon parts are actually governed by de facto the same rule. So it’s fairly straightforward.

“You need the CAD screen to see it, because you’re taking cross sections of a 3D surface, so it’s fair to question I suppose when it’s difficult to tell without that CAD data to prove it’s within the boxes it should be in and to prove it’s a continuous surface. But that’s really all it is.”

McLaren’s concept has already grabbed the attention of its rivals, with Key believing they could copy the design within the opening races.

“I think the first port of call with any idea you see out there is CFD, so I think you can jump on an idea that you spot on another team within a week easily nowadays,” Key said. “I guess if there’s still interest after a week, whether it’s our diffuser or Mercedes’ edge of floor detail or whatever it is, I think you can get a feel for things quite quick.

“Then it’s really understanding how it works with your car. That’s the key to this. You can then end up with a unique geometry of your own because you might understand the principle, but then you have to adapt it accordingly that it works with your car. The diffuser situation for example is also very stable in that environment as well.

“So you’d probably therefore wind tunnel test it, which might be a week or two down the line, and then you’ve got to manufacture it. These particular steps are pretty straightforward. So you could say between three and five weeks between taking the picture and putting it on the car if you really wanted to push this through.”

Key praised the team’s aero department for its quick thinking, having realised it could design around the rule changes.

“I think it’s always nice for a team to come up with an idea which is unique and the credit fully goes to our aero department and the guys in the rear aero group for realising that there was an opportunity there to use the new regulations in such a way,” Key said.

“I suppose it’s one of the visible things which gets talked about a lot, but ultimately it’s just a bit of a much wider picture of a complex part of the back of the car. I’m sure it’ll be forgotten by the time we get back here in a couple of weeks’ time.”