Relief valves are an essential part of any internal combustion engine system; without relieving the pressures of rapidly expanding gasses, at some point one of the components will fail, often with explosive consequences.
The limits of pressure valves often correlate with the limits of performance, and this was part of the reason why the nuclear-powered car and the gas turbine car did not reach the production stage, limited to a number of concept cars and a few racing cars in the case of the latter.
However, the short racing history of the turbine car would inspire and subsequently end one of the most revolutionary eras in motorsport history.
In some respects, the turbocharger works in a similar way to a gas turbine by using exhaust gasses to spool up a turbine that compresses air and forces the denser air into the engine, which increases performance relative to the size of the engine displacement.
Turbochargers are a common sight in cars now as a way to improve performance, fuel economy and emissions in smaller cars, but in the late 1970s, they were far more associated with performance.
The first notable turbocharged racing car was the Renault RS01 in 1977, but whilst this original car was far from competitive, becoming rather infamously known as the “Yellow Teapot” for its tendency to overheat in often comic fashion, just two years later the company won its first race.
It took a long time for other competitors to catch up, manage the inherent delay in throttle response (often known as turbo lag) and fix the reliability issues with early turbo designs.
Eventually, some of the fastest racing cars ever made, with power ratings of as much as 1400 horsepower for so-called “grenade” engines were recorded, all based on a technology banned for seemingly not being good enough.
However, turbos were also banned after five years of falling to control speeds and improve fairness for teams that used naturally aspirated engines, with the logic being that since the rules already banned turbines, they should ban turbochargers as well.
Turbochargers have since returned to motorsport, primarily because they are so highly efficient that many cars use them today.
