This V10 was one of the greatest engines in the history of Formula 1. It was introduced to meet a new set of regulations that came into force after the banning of turbos.
After a change in the Formula 1 regulations outlawing turbocharged engines for 1989, there was a rush to build the best of the new-format engines. The RA 109E was a normally aspirated 3.5 litre V10 and the power output was up to 685bhp by the start of the 1989 season.
Honda made eight RA109E available, but these were modified before the opening. There was a weight penalty with this, and the inevitable delay to testing as the chassis had to be modified too, but Honda reckoned that it was a sacrifice worth making to get more accurate valve timing. Another factor that had to be considered by the MP4/5 designers was that the RA109E needed more cooling than the smaller turbo that preceded it, because unlike them it had no intercooler.
Midway through the season, Honda also brought along a lighter version of the engine, with a further reduction in weight coming in time for the Belgian GP
McLaren’s dominance was such, though, that the team collected the constructors’ title for the second year in a row.