It’s not something McLaren is dismissing but asked if the chosen route for the new car’s aero platform was unambiguous, Marshall replied: “You kind of think there’s a lot of freedom but when you actually draw it out there’s not that much because there are boxes you have to stay within. The wheelbase is shorter by regulation. The engine is fixed length, your gearbox cluster and driveshafts positioning are fixed, you need a certain amount of fuel in the car and that sets your fuel volume. Now the new energy stores are [bigger]. Then you have a driver volume and his protection and so really you have only 150-200mm of car that you have control over the length of. The front nose is pretty mandated, so you have a bit of bellhousing and some stuff around the pedals you can play with. So there’s not an awful lot of freedom. Hopefully everyone else has come up with the same sort of conclusion. If there’s more freedom we’re not aware of it.
“In terms of packaging the fuel volume is less but the batteries are bigger, the tub is simpler, making the packaging a bit easier. So some things help, some don’t. But [in terms of] freedom you’re restricted by regulation boxes you can’t control.”
Just like almost all F1 engineers Rob is notoriously reticent to go into too much detail. But it’s interesting he mentions the regulation boxes – because within them, there appears to be a possible opportunity for differences which could be aerodynamically significant: cockpit positioning and front axle line. The rear face of the cockpit has to be between 1830-2030mm from the front of the survival cell, giving a 200mm range of where within the wheelbase to site it. Additionally, the front axle has a 150mm range, again as measured from the front of the tub. So we are not talking about different lengths of car here. Just different geometries within the same length.
Why might this be so significant? Because there is another dimensional stipulation – new for these regs – that the top of the nose and the cockpit sides should follow a curvature prescribed by a notional circle with its circumference mid-point mid-cockpit; so with the nose rising up and the top of the chassis falling away all in the same radius. What this means is that the closer you can bring the cockpit and front axle together, the higher your nose can be. Which in turn means, the greater mass airflow you can feed to the underfloor.
Bodywork ahead of the sidepods will push turbulent wheel wake into the floor
FIA
The complication of that is that the FIA has also mandated in-washing ‘floor boards’ roughly where the pre-’22 barge boards used to be. They are there to take the front wheel wake into the floor. Out-washing is better aerodynamically, in-washing narrows the wake for the following car. Bringing the front wheels and cockpit closer together will give you less opportunity of minimising that in-wash. But where is the optimum trade-off? And might there be a packaging trick which allows full potential to be taken of a higher nose? These are the sort of first order choices a new formula brings and invariably after a season or two they narrow down to a uniform optimum.
There may be nothing in it, but such puzzles present a fascinating anticipation about where the secret honey is located and who might have found it. If under a new reg set McLaren, as a customer team, can take up where it left off, it would be arguably even more impressive than its fight back to the front over the last few years.