Though turbocharged engines were developed for racecar engines prior to 1970′s, it was in the late 70′s viz.. 1977-78 when most of the Formula 1 teams started developing turbocharged engines. A huge proportion of their funds were utilized towards the R&D of turbocharged engines. Teams like BMW, Renault and Honda were the first ones to start off work in this direction.
The scene before this:
From the late 60′s most of the F1 teams used Ford’s Cosworth DFV 3.0L V8 or Ferrari’s flat-12. The Cosworth engine had a 4-valve arrangement and both the engines produced approximately a power of 525 horses. During this era itself, the aerodynamic development also grew to a large extent. The teams were able to craft a design which generated high downforce with minimum amount of drag in the car, thus increasing the handling of the car without affecting its performance.
The first turbocharged engine
In the earlier days, teams used supercharged engines. As per the regulations, the forced inducted engines should be half the size of the naturally aspired engines. Renault had become the first team to start the development work of turbocharged engine. Renault transferred most of the resources towards the development of these turbocharged engines. The force-inducted engines had to be half the size of the naturally-aspired Cosworth engines. Hence, their total engine capacity was restricted upto 1,500cc.
It could look that as the turbocharged engines were half the size of the naturally-aspired engines they will be lighter in weight, but due to the significant mass of the intercooler, there was no advantage. In fact, the extra drag caused by the intercoolers proved to be a disadvantage. Turbo charged engines proved to be significant in their initial stages. They had better performance on high altitude tracks, as the turbine could pump air at a higher pressure.
The First Win
After debuting in 1977, two years later in 1979, Renault was the first team to win a race with a Turbo charged engine. Impressed by this, all the teams started to build turbocharged engines. In 1983, BMW was the first team to win the championship with a turbocharged engine.
The issues
The early turbocharged engines used the diesel intercoolers and hence they had a very low compression ratio. They even used the mechanical fuel injection system. The biggest problem faced by them was during the delivery of rich mixture to the engine and the ignition timing. The teams had to move a step backwards from the mechanical fuel injection to the butterfly throttle due to the concern that the slide throttles could affect the boost pressure.
In those days, the pressure boost wasn’t much; it was just about 2.5 bars. The whole idea was to concentrate more over intercooling. These engines delivered around about a power of 640 horses, which was more than that of the 3.o L Cosworth
DFV engines.
Initially the turbocharged engines were able to push upto only 10,000 to 12000 rpm whereas as the Cosworth was able to red line upto 13,000 rpm.
The Development
Later on, all the teams were able to boost in higher pressure. There was a stage when all the teams were able to boost at least 3.5 bars. All teams were trying boost in higher pressure. Even tough there were many engine failures but the teams were able to boost greater pressure. BMW was able to boost in a pressure of 4.5 bars during the qualifying which was able to generate a power of about 1000 horses. As the engine had to last the entire race, the pressure boost was reduced leaving the engine with 750hp. By this time the turbocharged engines had left the naturally aspired engines way behind.
In the following year, the pressure boost in the qualifying reached upto 5.0bar, and these high pressure engines generated approximately 1100hp. As time progressed, safety had become an important issue as at times, the drivers found it difficult to control the car when the turbo kicked off. Hence, considering safety as the primary focus, in 1987 the teams had a boost limit of 4.0bar and a fuel ration to further reduce the pressure boost. As developing a race car winning with a turbo engine under these norms was proving to be difficult, teams reverted to the naturally-aspired engines. The year 1988 turned out to be the final year in the history of F1 turbocharged engines. In 1988, a few more rules were applied on the turbo powered engines; the boost limit was further reduced to 2.0bar. With turbo-era on the extent of its verge, showed some phenomenal results, as the two Mclaren drivers Ayrton Senna and Alain Prost won 15 out of the 16 races held in 1988.