To blow or not to blow?

This question is open to several interpretations. In an alcohol check the answer is a foregone conclusion. Blowing is, in some circles, a reflection of a driving style. Sooner or later you will also come up against the long arm of the law here. This story is about neither of these two subjects.

For engines to function properly, they need air. This air is drawn in and then mixed with the fuel, after which it is admitted to the combustion chamber as an explosive mixture. This can be done in two ways, via a carburetor or by injection. The explosion caused by igniting this mixture with the spark plug sets the piston in motion. When this also happens in quick succession in the adjacent combustion chambers, the engine runs.

Instead of drawing in air in the normal way at atmospheric pressure, a compressor can also be used to increase the amount of air in the cylinders. The compressor forces air under pressure into the engine intake manifold. Because there is more air in the cylinder, more fuel can be added and burned. This causes a larger explosion and thus increases the engine power.

The compressor is driven by the crankshaft (supercharger) or by a small turbine that uses the energy in the exhaust gases (turbocharger). Turbo is a contraction borrowed from English of turbine and booster. The exhaust gas drives the turbine and because it is on the same shaft as the compressor, the compressor is also driven. An engine equipped with a turbo is characterized by a "spaghetti" of pipes running to the turbine, as can clearly be seen below on the engine block of the Sauber-Mercedes C8 from 1985.

The advantage of a supercharger is that it responds immediately and delivers boost even at low engine speeds. The downside, however, is that power is lost in driving the supercharger, so part of the extra power gained is lost again. A turbo does not have this problem, but it suffers from what is known as turbo lag; only when the engine reaches a certain speed does the turbo receive enough exhaust gases to let the compressor do its job.

The supercharger was first used by the renowned American manufacturer Chadwick in the early 1900s. During the development phase, a normal engine produced 80 hp, while with a supercharger it produced 100 hp.

The major breakthrough for the compressor came from the aircraft industry during the First World War. The engines of airplanes lost a lot of power above a certain altitude because the air there is thin. As a result, less fuel mixture explodes in the combustion chamber, causing the engine to lose power. By using a compressor, this problem was more or less solved.

In the period after 1918, the new technology was mainly applied in racing. In this branch of sport, extra power was of course always welcome. One of the most classic examples of this can be found in the early years of Formula 1. The regulations in 1950 and 1951 allowed 1.5 liter engines with supercharger or 4.5 liter engines without. The playing field looked as follows: Alfa Romeo and Maserati had a number of supercharged cars. The French had the Talbots and Delahayes with 4.5 liter engines. There was a newcomer, called Ferrari, which was going to try it with the legendary 12 cylinder 1.5 liter engine (with). This car turned out not to be fast enough, and a new 12 cylinder engine (without) was soon designed. Slowly but surely, the cars with these naturally aspirated engines became competitive.

In 1951 the real showdown arrived; the Alfas with 1.5 liter supercharged engines had reached the end of their development, but were by then delivering more than 400 hp while consuming enormous amounts of fuel.

The Ferraris delivered only about 380 hp but were much more economical. It was the classic case of the hare and the tortoise. The slightly faster Alfas sometimes had to refuel twice, while the Ferraris needed to do so at most once. The recently deceased Argentine driver Jose Froilan Gonzalez broke the spell.

During the British Grand Prix at Silverstone, the Alfas were defeated in a heroic battle. In the end Alfa became world champion that year, but at Alfa Romeo in Arese they understood: you have to stop at your peak. And that is exactly what they did.

Incidentally, the Ferrari 375 Indianapolis in the Louwman Museum is originally one of those Grand Prix cars from 1951. After a few modifications, this car was entered in the 1953 Indy 500.

For the time being, the compressor era in Formula 1 was over. In endurance races they were still being used. The remarkable thing was that it was actually a participant in these endurance races who brought the turbo back to Formula 1. It was Renault in 1979. While almost every constructor (with the exception of Ferrari) was running Ford DFV engines, the French brand arrived with a six cylinder turbo engine of almost 1500 cc, which had already been used in endurance racing.

Initially the power output was only slightly higher than that of the Ford DFV engine, but it soon surpassed the roughly 550 hp that these dual four valve engines delivered. After Renault, other manufacturers also threw themselves into the Formula 1 engine market, such as Honda (which had withdrawn in 1967), of course Ferrari, Porsche (another one that came back) and later BMW. Because the drivers struggled with the turbo lag and had to develop a new driving style, the traditional engines managed to hold their own for a while longer. The last victory for a DFV engine in Formula 1 was achieved by Michele Alboreto in a Tyrrell during the Detroit GP in 1983. This was a so‑called street circuit where the turbos were at a major disadvantage.

As so often happens in Formula 1, things got a bit out of hand. BMW supplied the engines for the Brabham team, which at the time was owned by Bernie Ecclestone. These were fairly special engines that, despite their limited displacement (< 1500 cc), were reportedly able to produce more than 1000 hp. Fun on the straights, that much is certain. What was especially entertaining for the spectators were the huge flames shooting from the exhausts at the turbos. The governing bodies felt that developments had gotten "somewhat" out of hand and decided to ban the turbo once again starting from the 1989 season.

And now, in 2014, the turbo is back, as can clearly be seen on Renaults V6 F1 engine.

Opinions on this are strongly divided. The engine noise is muffled and no longer gives you that goosebump feeling. Fuel consumption has gone down quite a bit though. The Alfas from the fifties did 1:1(!), while consumption now seems to be 1 liter for every three to four kilometers. Progress?

Peter Helbach