After three years among Formula One's backmarkers, big decisions were made at McLaren to switch from Honda power to Renault over the winter. Released bright and early this morning, the new MCL33 represents the next step for the team as it looks to return to the front of the pack with its new power unit. But with large areas of the car remaining bare in launch spec, it's clear that the MCL33 seen today is only half a step towards the final Melbourne package that will race next month.
In truth, McLaren's woes started before Honda came on-board. The team was already struggling compared to similarly-engined rivals and the partnership with Honda was supposed to give McLaren the works-team edge it had lacked since Mercedes started switching its attention to its own factory outfit in 2010. But the Honda partnership did not got to plan and midway through last year McLaren chose customer status with Renault over a works deal that wasn't working.
Switching power units
A byproduct of Honda's problems was a lack of running due to reliability issues and having to set the car up with a down on power engine. While the Renault package was no bastion of reliability last year, it's hoped that at last McLaren can get some pre-season testing mileage under its belt to gain a better understanding of its car.
The other fallout from the engine switch was the late decision affecting design and lead times. The Honda power unit follows Mercedes' split-turbo philosophy, while Renault has a turbo wholly mounted at the rear of the V6 engine. Thus, the chassis designed for the Honda needed space to the rear of the fuel tank area to house the tubo's compressor and its airbox whereas the Renault's engine front is cleaner while housing some of that same hardware behind the engine. Both solutions have their merits, but McLaren had to part design a car that could take either engine, eventually having to repackage the rear end for the Renault layout.
As F1 engine sizes are fixed in many dimensions, the volume the aerodynamicists had to work around was similar and the team feels the car would have ended up looking similar with either engine. But under the skin some changes were beneficial. The entire engine can be moved forwards allowing the rear of the car to be a little slimmer, with the tradeoff of a revised gearbox case to house a complete turbo, not just the exhaust-driven turbine.
Engine change notwithstanding, McLaren has the resources to develop the aero and the chassis simultaneously, so this shouldn't be a reason for the outwardly simple changes to the car for 2018.
Is the McLaren underdeveloped?
As with Red Bull -- the other Renault engine customer -- the sidepods are slim with tiny inlets, although McLaren have retained their old concept here and not a high-top inlet design as on the Red Bull. Much of the rest of the MCL33 is strikingly similar to the old car, while the team has already confirmed there will be a big update for Melbourne. But with most of the other teams planning a similar update, it seems strange that so much would be left off for testing when so much can be learned from the upcoming eight days of running at the Circuit de Catalunya.
Again, the car is steeply raked, with a high rear end and nose-down attitude. Familiar shapes can be seen with a hugely complex front wing, multi-vaned front wing mounts and the similarly-slotted rear wing endplates. The bargeboards are complex and have evolved from 2017, but this area is lacking the more extensive work others have applied, with just two rows of fins over the top of the sidepod -- a solution discarded by most teams in the early 2010s.
Curiously missing is the S-duct in the nose, and although we can see its inlet under the car, some of the turning vanes are missing. Of course, all this can be retro-fitted so we can expect that this will all be part of the MCL33's Melbourne specification. In terms of what's new, we can see long slots along the floor edge -- most teams ran these in 2017 and they increasingly grew during the season -- but McLaren's are now nearly the full length, suggesting much of the floor is in its first race specification.
Other changes can be found at the rear suspension, specifically the top wishbone, which is usually a "V" shape where the two legs meet near the rear wheel mounting. Instead McLaren have merged the two legs and a single straight arm extends from the sidepod to reach the wheel. This is a clean solution and the narrow arm that's formed sits out in the airflow and will be helping to direct that airflow down through the rear wing.
Obviously, a lot has been done to the car for 2018, but from the exterior that's visible today, there isn't enough to suggest McLaren has made a significant step. However, as developments appear through testing and on arrival in Melbourne we should get a better idea how brave McLaren has been over the winter.