2026 Aerodynamic & Chassis Regulations

[johnnycesup]

wasn't that ground effect with SKIRTS holding in the air ?

totally different to anything allowed in the last 45+ years

Let's look at more recent stuff then shall we:

https://www.linkedin.com/pulse/what-par ... illem-toet

From Willem Toet's linkedin post about a 2009 F1 car, the "floor and diffuser" is 3.5 times as efficient in L/D than the rear wing, and 2.8 times as efficient than the front wing. I imagine his knowledge of the actual drag and lift figures should be beyond question.

https://www.f1technical.net/features/21667

From a very good article in the main F1technical site about the post 2017 rules, the "underbody and diffuser" is 5 times as efficient than the front wing and 3.6 times as efficient than the rear wing.

https://www.davidpublisher.com/Public/u ... 15a456.pdf

From a paper using cfd to simulate a 2017 f1 car, the "underbody + plank" is 2 times as efficient as the front wing and 2,8 times as efficient than the rear wing.

I'd love to see someone with a different result.

[Vappy]

The floor has always been the most critical part of creating effective downforce, in part due to the lower cost of drag.

[vorticism]

Look at those inwash boards. The whole claim to fame of these regs is inwash and yet they couldn't even manage to get these boards to actually inwash. Air just goes right through them.

https://i.postimg.cc/5N82Lbnw/q11.jpg

They are still inwashing. It's only a general term. The legality box for the floor board forces an inward angle regardless of interpretation. Even if that box wasn't angled inward, say the box was straight or even slightly turned outward, the presence of vertical bodywork in that location will be impeding outward flow through that area (generally speaking, paired with a typical outwashing sidepod). "Impeding outwash" would be another way of saying inwash, ultimately.

[Nineosix]

Just had a thought about the 2026 active aero rules and wanted to throw it out there.
So we know the wings will move between modes on straights and corners for drag reduction. But what if teams could use those wing adjustments to mess with the airflow going to the diffuser? Like when the rear wing goes flat, maybe it changes the pressure enough to make the diffuser stall or work less efficiently, giving you even more drag reduction on top of what the wing itself does.
Same thing with the front wing affecting the vortices that feed air under the car. Could you set the wing angles to deliberately screw up the diffuser flow in low drag mode?
Is something like this even allowed in the regulations or are the wing positions going to be so strictly defined that teams can’t really play around with it?
Anyone know if this kind of thing is realistic or am I just overthinking it?

[TeamKoolGreen]

The 2026 regulations will feature a return to flat floors in part to drastically reduce overall aerodynamic drag, which is necessary for the new hybrid power units to function efficiently on straights. The new power units shift to a near 50/50 split between combustion and electric power, requiring a significant reduction in aerodynamic resistance to manage energy effectively.

What's the source on this?

The underbody is a lot more efficient in L/D than a wing, that is very much proven. That's why teams come up with skinny low drag wings for Monza and Vegas (until now, where there was only DRS in terms of active aero), not flat floors.

The Race from 2023.

First off, everyone seems to have forgotten completely the timeline of events. 2026 was ONLY supposed to be a power unit regulations renewal. Nothing else.

This is the timeline of events:

2026 power unit regulations. Key pillars:

Maintaining the 1.6-liter V6 turbo hybrid engine architecture.

A significant increase in electrical power (up to 50% total power).

Use of advanced, 100% sustainable fuels.

Removal of the complex MGU-H component to reduce costs and attract new manufacturers like Audi and Ford.

January 17, 2023: Articles detailed the immediate 2023 technical rule changes (such as floor edge height adjustments and stricter roll hoop tests) while mentioning that these rules were a lead-up to the all-new 2026 generation.
(so far nothing about scrapping the venturi floors)

June 20, 2023: The FIA published a detailed version of the 2026 Power Unit Technical Regulations.

Late 2023: Discussions began to emerge regarding the need for accompanying chassis and aerodynamic regulations to work in tandem with the new power units, including early talks about potential active aerodynamics and a focus on lighter, more agile cars. The engine development was frozen until the end of 2025 to allow focus on the new era PUs.

It was only after the tests of the new Frankenstein power units, that they had to decide to completely change the whole car to make the new PU's work.

[carisi2k]

Look at those inwash boards. The whole claim to fame of these regs is inwash and yet they couldn't even manage to get these boards to actually inwash. Air just goes right through them.

https://i.postimg.cc/5N82Lbnw/q11.jpg

They are still inwashing. It's only a general term. The legality box for the floor board forces an inward angle regardless of interpretation. Even if that box wasn't angled inward, say the box was straight or even slightly turned outward, the presence of vertical bodywork in that location will be impeding outward flow through that area (generally speaking, paired with a typical outwashing sidepod). "Impeding outwash" would be another way of saying inwash, ultimately.

That inboard will be useless when the teams power up the sidepod outwash. If they truly wanted to get rid of outwash they needed to square the sidepod from the inwash flap all the way to the rear wheels.

[TeamKoolGreen]

Here it is right from Ben Sulayem mouth and from the F1 website from June 6 2024

FIA President Mohammed Ben Sulayem said: “Today, the FIA is defining a hugely exciting future for the pinnacle of motorsport with the launch of a comprehensive new set of regulations for the 2026 FIA Formula One Championship and beyond.

“Following the publication of 2026 power unit regulations two years ago we have we have taken opportunity to redefine the chassis regulations to match the energy requirement of the new power units.

https://www.formula1.com/en/latest/arti ... qsVQtDr2UB

It had nothing to do with improving ride quality, nothing to do with ride height or stiffness, nothing to do with the rain being kicked up. The chassis regulations weren't even up for renewal.

[djos]

Here it is right from Ben Sulayem mouth and from the F1 website from June 6 2024

FIA President Mohammed Ben Sulayem said: “Today, the FIA is defining a hugely exciting future for the pinnacle of motorsport with the launch of a comprehensive new set of regulations for the 2026 FIA Formula One Championship and beyond.

“Following the publication of 2026 power unit regulations two years ago we have we have taken opportunity to redefine the chassis regulations to match the energy requirement of the new power units.

https://www.formula1.com/en/latest/arti ... qsVQtDr2UB

You are conflating the redefined chassis rules with ground effect efficiency, there is no relationship.

The FIA’s head of single-seater matters Nikolas Tombazis said: “It is much less of a Venturi effect than the current generation.

“The main driving force for that is we wanted to have cars that are not quite running as close to the ground as current cars, so maybe we try to relax a bit that aerodynamic mechanism.”

https://au.motorsport.com/f1/news/why-f ... /10665845/

[TeamKoolGreen]

Here it is right from Ben Sulayem mouth and from the F1 website from June 6 2024

FIA President Mohammed Ben Sulayem said: “Today, the FIA is defining a hugely exciting future for the pinnacle of motorsport with the launch of a comprehensive new set of regulations for the 2026 FIA Formula One Championship and beyond.

“Following the publication of 2026 power unit regulations two years ago we have we have taken opportunity to redefine the chassis regulations to match the energy requirement of the new power units.

https://www.formula1.com/en/latest/arti ... qsVQtDr2UB

You are conflating the redefined chassis rules with ground effect efficiency, there is no relationship.

The FIA’s head of single-seater matters Nikolas Tombazis said: “It is much less of a Venturi effect than the current generation.

“The main driving force for that is we wanted to have cars that are not quite running as close to the ground as current cars, so maybe we try to relax a bit that aerodynamic mechanism.”

https://au.motorsport.com/f1/news/why-f ... /10665845/

That article is dated months after Ben Sulayem's satement. He was clear. They have since started piling on other reasons why the flat floors and active aero have been added. For example, they say the active aero is there to create more excitement and driver engagement. Do you believe that too ?

The chassis regulations were not even up for renewal and weren't even a discussion from August 2022 to late 2023. It was only after simulating the 2026 power units that they realized they had to cut as much drag out of the car as they could. And that's when the active aero and flat floors came in. Getting rid of the venturi drag wasn't even enough. They had to add active aero also.

[djos]

Here it is right from Ben Sulayem mouth and from the F1 website from June 6 2024

FIA President Mohammed Ben Sulayem said: “Today, the FIA is defining a hugely exciting future for the pinnacle of motorsport with the launch of a comprehensive new set of regulations for the 2026 FIA Formula One Championship and beyond.

“Following the publication of 2026 power unit regulations two years ago we have we have taken opportunity to redefine the chassis regulations to match the energy requirement of the new power units.

https://www.formula1.com/en/latest/arti ... qsVQtDr2UB

You are conflating the redefined chassis rules with ground effect efficiency, there is no relationship.

The FIA’s head of single-seater matters Nikolas Tombazis said: “It is much less of a Venturi effect than the current generation.

“The main driving force for that is we wanted to have cars that are not quite running as close to the ground as current cars, so maybe we try to relax a bit that aerodynamic mechanism.”

https://au.motorsport.com/f1/news/why-f ... /10665845/

That article is dated months after Ben Sulayem's satement. He was clear. They have since started piling on other reasons why the flat floors and active aero have been added. For example, they say the active aero is there to create more excitement and driver engagement. Do you believe that too ?

The chassis regulations were not even up for renewal and weren't even a discussion from August 2022 to late 2023. It was only after simulating the 2026 power units that they realized they had to cut as much drag out of the car as they could. And that's when the active aero and flat floors came in. Getting rid of the venturi drag wasn't even enough. They had to add active aero also.

Ben S is a politician, he has no idea what he’s talking about. Here’s another article that’s only 7 days old and sums up the reason for the changes quite well.

But the cars it created ultimately became exactly what the rules set out to avoid, extremely difficult to race thanks to how difficult it became to follow.

They produced enormous levels of downforce and were seriously fast, and were challenging to drive even if they did take a big physical toll on the drivers. But they struggled to follow closely and created processional races.

So what went wrong?

The short answer is that the teams did everything they could to ‘break’ the regulations in their relentless pursuit of performance and race wins.

https://www.the-race.com/formula-1/how- ... ffect-era/

[De Wet]

Why are the Aerodynamic Testing Restrictions in place for 2026 if everybody is starting with a clean slate ?

[AR3-GP]

Why are the Aerodynamic Testing Restrictions in place for 2026 if everybody is starting with a clean slate ?

F1 uses balance of performance to make sure everybody wins.

[johnnycesup]

The Race from 2023.

Got a link?

My recollection of events is that there was indeed a massive need for drag reduction, hence the introduction of active aero for everyone and the narrower tyres and cars, and they took the opportunity to make the cars a bit less peaky, stiff and bouncy by reintroducing a flat floor.

Everyone knows the underbody is pretty much the most efficient downforce you get in an f1 car, by a factor of at least 2. If the mods can approve my post, I came with the receipts.

[jjn9128]

The folks over at Symscape seem to agree:

In a brilliant example of lateral thinking the Lotus team applied the well known "airplane in ground effect" principle (reduced drag) to a racing car and found a significant increase in downforce with minimal increase in drag as a result.

https://www.symscape.com/blog/secrets_of_diffusers.html

There are a number of "ground effects" the which work for aircraft are ram pressure and circulation cancellation, the latter one reduces the bound vortex strength so reduces induced drag (less tip vorticity). F1 ground effect will be venturi principal which lowers static pressure with the reducing ground clearance. As a result pressure gradients are steeper and boundary layer loses increase. There's also circulation cancellation which reduces the wake upwash.

That said the floor is one of the more efficient parts of the car, off the top of my head front wing and floor will be order of 8:1-13:1 L/D depending on regulation generation and circuit. Rear wings are less efficient, but partly due to aspect ratio as much as the lack of ground effect.

[TeamKoolGreen]

The Race from 2023.

Got a link?

My recollection of events is that there was indeed a massive need for drag reduction, hence the introduction of active aero for everyone and the narrower tyres and cars, and they took the opportunity to make the cars a bit less peaky, stiff and bouncy by reintroducing a flat floor.

Everyone knows the underbody is pretty much the most efficient downforce you get in an f1 car, by a factor of at least 2. If the mods can approve my post, I came with the receipts.

Clearly the huge venturi floors produce more drag than a flat floor with a diffuser. Even if it is less relative drag than wings. And that is why the flat floor is back.

Everything , including the narrower car and narrower tires, flat floor and active aero was introduced because the new PU's could not handle the drag after the simulations were done in late 2023.

Can you show me anywhere where it says that the chassis regulations were up for renewal in 2026 ?