F1 innovations: Honda’s unraced hybrid

F1 at 70

When Honda pulled the plug on its F1 project at the end of 2008, the car may have lived on with Brawn GP badging, but its innovative hybrid system was lost.

Honda hybrid innovation header

Honda's RA108 was used to test Honda's hybrid concept

Grand Prix Photo

It is easy to forget in this age of V6s that from 2009, Formula 1 already ran hybrids thanks to the addition of KERS (Kinetic Energy Recovery Systems). As the V8s were naturally aspirated, this was the only energy recovery option available and the systems were capped at a maximum output of 60kW.

Not all teams opted to run a system in 2009, but through the 2008 season, many tested their new designs with most settling on a layout not too dissimilar to those seen today; a battery mounted in the centre of the car with the KERS MGU (motor generator unit) next to the engine. Williams did develop a flywheel system but never raced it, and Honda also considered a flywheel.

However, Honda did design a battery-based KERS car for 2009, which never raced and was substantially different to that which would go on to become the BGP 001. It was the RA109K, developed in tandem alongside the RA109 non-hybrid. While it may come as no surprise a company such as Honda wanted to be onboard with KERS, it went about it in a way that was quite removed from what would come to be seen as ‘conventional’.

Normally, developments like this would be lost to the mists of time when a team folds, but fortunately, Honda’s R&D department published a in-depth internal document covering what it terms its ‘3rd era’ in Formula 1, which included many details of the unrealised RA109K.

Prior to the development of the 2009 car, Honda used both a modified RA106 (called the RA1082 in-house) and an RA108 (RA1089) for KERS concept testing. In the first car, it took the approach of placing the battery etc in the area of the fuel cell, but with the MGU in the transmission casing. However, it deemed that this layout both reduced fuel capacity and was detrimental to aero performance. Therefore, with the RA1089 and RA109K, it went for a decidedly innovative approach.

Instead of siting the battery in the monocoque, it chose to package it under the nose. Development between the 2008 prototype and the RA109K eventually saw the use of a long thin battery pack, which extended from roughly where the driver’s knees are to the junction between the tub and the nosecone.

This layout presented a number of challenges when it came to crash worthiness, as both the battery and power control unit were outside of the main monocoque, but Honda engineers were confident they had these issues solved and it would pass the relevant FIA tests.

Related article

Similarly unique was the location of the MGU. If it was placed on the crank centreline, at the front of the engine, this would again compromise the space available for the fuel tank. Honda’s solution? Place the MGU out to the side of the car near the base of the left hand sidepod, with drive transmitted to the crank by a series of five gears. Interestingly, Honda was also relying on the engine oil to cool its motor.

The RA109 never ran, but the RA1082 and 1089 were track tested, the former at Silverstone and the latter at Santa Pod on November 28, 2008. It was due to test again a couple of weeks later at Jerez, but on December 5, Honda pulled the plug on Formula 1. The current rules wouldn’t allow for such a layout today, and it would have been fascinating to see how Honda’s unusual hybrid would have fared, given the success of the Brawn in 2009.