Red Bull RB21

[Vanja #66]

Thank God for Auto Racer!

[Cs98]

That's a pretty big redesign for mid season. Changing the shape of the inlet is one thing, but the mid wing is totally new.

[Silent Storm]

First major upper bodywork upgrade of the season, and first major sidepod change since arguably the start of 2024

The full sidepod is not visible yet, but the inlet has become a more standard shape (abandoning sharkmouth) and a midwing is now present. Very similar to McLaren's 2025 sidepods with the mirror stay accommodated at the tip of the midwing

Also can see the horizontally stacked intercoolers for the central-line cooling are still present. This wasn't abandoned yet

Autoracer Imola 2025
https://autoracer.it/wp-content/uploads ... caled.webp

Miami (for comparison)

https://img.auto-motor-und-sport.de/_/b ... 201940.jpg

The fact that they’ve retained the central line intercoolers suggests one of two things...

1) They’re not the primary contributor to the internal flow mismatch or
2) Red bull is deliberately sequencing these changes, validating pressure fields and heat rejection step by step before committing to more invasive packaging revisions.

Switching from the sharkmouth to a more conventional inlet likely improves pressure recovery into the sidepod plenum. That smoother entry flow should reduce localized separation and swirl upstream of the radiator faces, precisely the kind of internal aero refinement we discussed as necessary to close the loop on tunnel track correlation.

It’s worth noting that while the inlet shape has changed and the midwing is a new addition, it doesn’t visually look like a major rework of the internal aero package... at least not yet.

[Silent Storm]

Side by side comparisons show a clear reduction in inlet width, but the vertical dimension looks similar or slightly larger. From what’s visible so far, this seems more like an external aero decision... Reducing frontal pressurization and redirecting upwash, rather than a direct fix to internal flow inefficiencies.

[organic]

Looks like they have introduced a strake/fence on the underside of the SP inlet in the undercut as well. Detail I've not seen on any other car to date

[Silent Storm]

Is that a strake under the inlet?

[organic]

https://pbs.twimg.com/media/Gq_WCmXWUAA ... name=large

Is that a strake under the inlet?

Think so.. don't recall seeing that on any other car to date

*Been pointed out to me by SonoDAS that W13 had a strake under the midwing

To me it looks like the strake may continue onto the next piece of bodywork, so we could see the full idea when the sidepod bellies are fitted

[CjC]

Looks like they have introduced a strake/fence on the underside of the SP inlet in the undercut as well. Detail I've not seen on any other car to date

Yea I guess that’s the ‘radical’ feature which is being reported

[CjC]

Is the mid wing bent backwards as well?

[organic]

Is the mid wing bent backwards as well?

I don't think so. Looks like it tapers the leading edge rearwards towards the wingtips just because of the legality volumes. But what I do see from some angles is the suggestion of quite aggressive dipping inboard on the sidepod upper surface. Maybe waterslides make a comeback

[Silent Storm]

From fabrega

[AR3-GP]

The surfacing of the S-duct inlet has evolved (I think?). There's a small channel created just underneath the sidepod inlet.

[Matt2725]

Someone will know, but which legality box allows for that strake to be under the sidepod?

[vorticism]

It's impressive they've been using air-air intercoolers since 2014, and won 4 WDC while using them them. Their intercoolers are a primary deficit to Mclaren in the context of the 2025 regs and the now-matured regs cycle in general, imo. Water-air radiators sacrifice some centerline packaging space in front of the engine in exchange for smaller sidepod heat exchangers. Look at the a-a intercooler in that photo. Now imagine it's not there... That's what the MCL39 has, which makes optimizing the engine cover easier.

[organic]

A nice view of the latest diffuser specification

photo by Francesco Bianchi