McLaren’s reunion with Honda was initially surrounded by plenty of hype, born out of the glorious memories from the golden 1988-1991 period. One thing has perhaps been overlooked though. In 1988, when the two partners won their first title together, the Japanese engine manufacturer had already been using and fine-tuning its V6 turbo for six years.
Last season’s nightmare has clearly poured cold water on the team’s hopes and forced Honda to revise its power unit, while still unlocking the most out of McLaren’s ‘size zero’ philosophy. Noticeable improvements are expected and the initial patience has nearly vanished.
A SCULPTED NOSE AND LOWERED SUSPENSIONS
While seemingly similar to the 2015 design, the McLaren-Honda MP4-31’s nosecone does include several small novelties. Instead of being flat, the nose has been hollowed out from its pointier protruding thumb tip up to where the middle of the SAP logo sits (see yellow outline), which gives the layout an original concave shape.
The edges connecting the tip to the front wing pillars used to be horizontal; they now are arched as on the last two Toro Rosso chassis. The rationale behind the slight tweak is to further increase the volume of airflow under the nose.
The front wing mounting pillars have been very carefully designed, considering their aerodynamic purpose is at least as important as their structural function. Thanks to their slightly elongated profile, the pillars create a sort of tunnel that channels the airflow coming from the front wing’s mandated 500 mm neutral section and travelling towards the under nose turning vanes, the splitter, and the sidepods.
The upright slits that have appeared on each side of the pillars are unprecedented and help better guide the airflow towards the vanes. Their inner face has been carefully sculptured and channels part of the airstream towards the ‘S’ duct system, which has a more aggressive layout compared to last year’s initial version.
The front brake ducts still are horseshoe-shaped, though they now sport an extra fenced inlet that draws inspiration from a similar Mercedes design.
CHASING A HIGHER RAKE ANGLE
McLaren still runs a high rake angle on its MP4-31 with the front end much lower than the back of the car. Chief engineer Peter Prodromou thus carries on treading the path he started to walk when he was working at Red Bull. By raising the rear ride-height, aerodynamicists look to increase the diffuser’s volume, and by extension its efficiency. The thing is, the higher the diffuser gets, the more exposed it also is: turbulences – mostly coming off the rotating front wheels – enter the low-pressure area laterally, which might end up hampering the diffuser’s effectiveness. This is the reason why aerodynamicists try to generate a series of vortices to seal the diffuser’s edges as much as possible.
By further embracing the ‘rake’ philosophy (also seen at Force India) engineers at Woking show they are confident they have overcome any splitter friction issues and protected the diffuser’s edges really well.
TRYING TO FIT A BIGGER TURBO
Former Honda motorsport boss Yasuhisa Arai told F1i’s Chris Medland that Honda needed to increase the turbo sizing on its 2016 power unit, while incorporating even more the ‘size zero’ concept. As a reminder, technical regulations mandate a 90-degree V6 engine, so the Japanese engineers had to find a clever way to free up some space inside the V6 so it can fit a bigger turbo.
Increasing the turbine sizing means that Honda might have further downsized other components, which could negatively impact reliability that was already quite poor in 2015. Ferrari’s 2014 power unit had also been hampered by its miniaturised turbocharger. The Scuderia managed to correct the issue last year but its engine architecture is not as constraining.
After last year’s disappointing season, there has been change at Honda with Arai stepping down from his F1 role ahead of retirement. Yusuke Hasegawa will replace him, having initially served as Jacques Villeneuve’s engine engineer before becoming Honda F1 Team’s head of engineering in 2008 before the Japanese manufacturer pulled the plug on its works outfit.
Honda’s extremely compact unit has enabled McLaren to radically trim down the rear end, especially in the ‘coke bottle’ area. While the ‘size zero’ was pretty unique to McLaren in 2015, the Ferrari SF16-H certainly represents Ferrari’s own interpretation of the concept (see comparison below).
A NEW REAR END
Despite its radical DNA, last year’s MP4-30 kept its predecessor’s mounting points at the back. The lower wishbone remained far behind the driveshaft, while the 2015 McLaren design could also still accommodate aero elements like the so-called ‘mushrooms’ and ‘bells’ (they were never run though). Prodromou joined the team in September 2014, so he was not able to modify the rear suspension up until the 2015 Abu Dhabi Grand Prix.
The latest layout is more conventional, with the lower wishbone being brought forwards to the gearbox and now lodged in a casing that also houses the transmission shaft. Thus, McLaren has better integrated the wishbone, which now obstructs the airflow less in this key area of the rear end.
The other major change can be found in the rear wing, with McLaren having gone for a different design philosophy for the endplates. Two very sculptured notches have replaced the seven vertical slots that featured in the lower part of the MP4-30’s endplates, a design that once again draws some inspiration from Mercedes.
A long vertical slit has also been added but while this is a first for McLaren the solution has already been seen at Red Bull, Mercedes, Ferrari, Force India and Toro Rosso.
The endplates also sport four other openings that sit right underneath the wing’s main board. By letting air flow from the outside to the inside, these apertures help even the pressure on each side of the endplate, thus curbing the intensity of the vortices that appear in the area where the endplates and main board meet. The serrated strikes (which have also appeared on the Williams FW38) have been replaced with continuous ridges.
Finally, as on last year’s Toro Rosso, the rear wing’s central pillar goes around the main exhaust tailpipe to be attached to the gearbox casing.
Having taken technical risks and tried unprecedented solutions on the MP4-30, the renewed McLaren-Honda partnership has extended and developed this audacious concept on its successor. Doing better than last year is almost a given but making only little headway will not be enough to vindicate the radical technological choices made over the past couple of years.