The 2021 world championship duel embodies a complete challenge, which sees drivers and teams as well as engineers as protagonists. Since the beginning of the season, the competitive spirit of the confrontation between Red Bull and Mercedes has characterized every single aspect of the competition, from the handling to the development of the cars, from the preparation work on the track to the regulatory controversies, passing through the performance of the power units. Just in the motor industry, both sides have recently emerged new insinuations that cast shadows on Mercedes and Honda engines, which in all likelihood will animate the discussions after returning from the summer break.
The definition of the current picture of the clash between Mercedes and Honda originates in the development carried out during the winter. The Japanese engineer has in fact worked hard to anticipate the debut of the power unit initially scheduled for 2022, equipped with profound innovations compared to the previous engine. The new combustion engine has been revised in the shape of the combustion chamber and in the inclination of the valves to improve the efficiency of the combustion itself, thus leading to an increase in power with the same consumption or vice versa to a lower fuel consumption without sacrificing performance. Honda technicians also have significantly improved the handling of the hybrid, partially sacrificing the efficiency of the combustion process, despite the improvements made. In this way, a sufficiently high level of thermal energy in the exhaust gas was maintained, useful for regenerating a greater quantity of electricity through the MGU-H, the electric motor-generator connected to the turbine, energy that can subsequently be exploited by the hybrid part of the power unit. .
Mercedes, on the other hand, worked in particular on the shape of the plenum, the volume from which the cylinders of the engine cyclically suck in the air necessary for combustion, as also declared by James Allison at the time: “Our friends at HPP did a considerable effort to redesign the plenum and the intake system, recalibrating the engine around it and consequently squeezing a lot more horsepower out of the power unit ”. The changes to the plenum were designed to accommodate a different orientation of the air intake horns directed to the cylinders, but it is still unknown whether this choice is the result of the desire to accommodate a different packaging of the components inside the bonnet or whether it has improved the volumetric efficiency and consequently the power of the heat engine. The hypothesis is that the new intake system allows to maintain a lower inlet air temperature, increasing its density. The novelties in any case are perceptible by the bulge in the bodywork visible on both the Mercedes and the Aston Martin.
Evolution during the season
With the start of the championship, the two power units appear separated by a minimum performance gap, so much so that it is difficult to establish who is the dominant engineer. With the arrival of the Azerbaijan Grand Prix, in Baku Mercedes introduces the second engine of the season to both cars, while Honda is postponing the debut of the new specification for both Red Bull and AlphaTauri to the French GP, thus being able to count on two more weeks to develop the planned innovations, although the current technical regulations prevent changes to the power unit per season in progress, except for reasons of reliability.
The second Honda unit has therefore been improved precisely in reliability, allowing for less conservative engine mappings and indirectly leading to a slight increase in available power. The same Toyoharu Tanabe, technical director of the Honda Formula 1 project, confirmed directly to FormulaPassion Reliability progress with the second seasonal power unit: “Really very small, almost negligible improvements, but if I used that term our development engineers could get angry.” In the hat-trick of races between France and Austria, Red Bull thus highlights the engine’s greater competitiveness compared to Mercedes’ rivals. In the double race at the Red Bull Ring however, the straight performance of the Milton Keynes stable also benefits the rear wing with simplified external endplates, a novelty introduced in Baku to reduce drag in high-speed circuits.
In June, Mercedes externalized its war intentions by means of James Allison, which states that a power unit upgrade program is being carried out in Brixworth: “We are planning updates both in terms of aerodynamics and as regards the power unit in terms of ‘delivery’. The engineers are working to allow the power unit to express something more ”. Even without physically modifying the engine, which would require the introduction of a third specification, Mercedes attempts to extract more power from the power unit by working solely on the management and delivery strategies of the hybrid. Honda itself proved at the beginning of the year that only with a different mapping of the heat engine it is possible to sacrifice combustion efficiency for the benefit of greater regeneration of the MGU-H through the exhaust gases.
The impression is that the reigning champion team will have these updates starting with the Silverstone race, where the W12s appear faster on the straight than the rival cars. If, however, the comparison in England is conditioned by the more exhausted aerodynamic set-up than the Red Bull, the appointment in Budapest provides further confirmation. Mercedes reaffirms its superiority on the straight, although the Silver Arrows are more charged than the RB16Bs, which even switch to a more discharged rear wing in the night between Friday and Saturday (version 2, below). Adrian Newey also denies the suspicion that Red Bull has adopted a more conservative engine mapping in order not to compromise reliability after the impact of Max Verstappen at Silverstone: “We have not reduced the power in the last two races, Mercedes must have found some Kilowatts recently“.
This leads to the current situation, where, as often happens, the dynamics of the competition generate bright tones, accompanied by suspicions and insinuations from both sides. As reported by Auto Motor und Sport, among the episodes under the magnifying glass there would be the duel between Lewis Hamilton and Max Verstappen at Silverstone. The car of the Englishman has in fact recovered several meters in the extension that precedes the Copse, highlighting a speed gap that according to some insiders would not be attributable only to the wake effect, but also to an important contribution of the power unit. Mercedes defends itself by stating that from the data available to them it appears that the Honda power unit at that point went to recharge and therefore has not delivered the maximum power available.
Auto Motor und Sport it also reports how Mercedes itself went on the counter-offensive, insinuating that Honda has suffered a drop in power in the last few races following a different management of the Japanese hybrid defined by the Federation. Asked about the matter, the FIA denied the existence of a technical directive aimed at regulating the Japanese power unit, but the German newspaper claims that such a decision may have been taken directly with the Japanese engineer in private, without the need for the publication of a document.
The editorial staff of Auto Motor und Sport concluded the review of the suspicions raised by the two title contenders with the doubts of Red Bull, apparently shared also by Ferrari. The Milton Keynes team suspects that Mercedes is able to cool the plenum, object of the main innovations during the winter, thus lowering the temperatures of the incoming air and increasing its density, thus being able to introduce a greater quantity of air and petrol into the cylinders to the advantage of the power released. However, no more detailed hypotheses have been formulated on how this can happen, if not by applying dry ice when the car is in the pits, the advantages of which vanish within a short time.
In this regard, article 5.6.8 of the technical regulation states that: “The air temperature in the plenum must be at least 10 ° C higher than the ambient temperature. When this compliance occurs, the air temperature is the average per lap of that recorded by the FIA […], during any lap in the qualifying and race sessions. The first lap of the race, the laps behind the Safety Car, those with a time 20% higher than the best time of the session, the entry and exit laps from the pits and any laps with obvious anomalies will not be used to establish the average temperature . […]”.
While such suspicions and allegations are not supported by concrete evidence, it is likely that they can animate discussions in the paddock after returning from the summer break. At Spa it will also be expected that Mercedes will be able to introduce the third unit of the season, with the consequent advantages on reliability and power already seen with the second Honda power unit. Red Bull, on the other hand, is likely to be forced to postpone the debut of the new specification, after both cars in Hungary were equipped with the annual third engine, but with the same characteristics as the previous version. The Belgian Grand Prix is thus outlined as a new chapter in the motorsport challenge between Mercedes and Honda, a battle of considerable weight in view of the race to the title.