Indianapolis 500’s Influence on American Automotive Innovation

Indianapolis 500's Influence on American Automotive Innovation
1921 Indianapolis 500 and 1921 French Grand Prix

As the first cars in the world hit the scene, automakers were really working with a blank slate, stealing ideas and bits of technology from existing transportation. So, for quite a while, folks were driving around with brakes that really weren’t all that different than what you’d see on a bicycle — and that really put a damper on being able to achieve higher speeds. So, for the 1921 Indy 500, Duesenberg pioneered a vehicle with four-wheel hydraulic brakes. Essentially, the brake fluid amplified the pressure in the braking system, which allowed cars to stop much faster without requiring a driver to use their full body weight to arrest its motion.

A supercharged engine is one that compresses the air taken into an engine to lend it more power and torque — and this technology was introduced to the 500 by Mercedes-Benz in the early 1920s. The marque by no means invented superchargers with that introduction, but it did come to popularize them in American racing and automotive circles.

The iconic Henry A. Miller became a pioneering force for front-wheel drive vehicles as opposed to rear-wheel drive, which helped stabilize the front-engined roadsters at the time.

Miller also patented the intercooler in 1931 after running it at Indianapolis in 1927. Basically, an intercooler helps reduce the temperature of the air that superchargers take in, which allows more air to be forced into the engine and therefore creates even more power. These didn’t really make it into the road-going sphere until Porsche introduced them on the 911 in 1977.

After superchargers came the next big step: the introduction of a turbodiesel-powered machine in 1952. That was the first attempt at turbocharging an Indy racing engine, but the concept didn’t really take off until the mid-1960s, when Joe Huffaker fitted his Offenhauser engine with a turbo.

How the 1965 Lotus-Ford Racecar Revolutionized the Indy 500

No, the British invading a country wasn’t specifically developed by the Indy 500, but the arrival of British marques in the early 1960s completely changed the name of the game in Indy 500 racing.

The sport had suffered a bit of stagnation in terms of chassis design after World War II, so most American Indy 500 entrants were competing in large, heavy “roadsters,” or front-engined cars. Jack Brabham showed up in 1961 with a rear-engined machine, and its elegant handling highlighted the fact that this new engine layout might have a distinct advantage on an oval, not just on the Grand Prix circuit. It wasn’t the first rear-engined car to appear at Indy, but it was the first to make a statement.

It really wasn’t until Colin Chapman showed up with his Lotuses, though, that Indy entrants took notice. In 1963, The Ford-engined machine finished in second place, stunning the naysayers who couldn’t believe that such a small, light car would have any competitive heft. The next year, Jim Clark drove his rear-engined Lotus to a pole position, and the year after, to a win. The rear-engined design proved so desirable that 1964 was the final Indy 500 ever won with a front-engined roadster.

The Silent Screamer – Andy Granatelli’s gas turbine car run at the 1967 Indy 500

The concept of a turbine engine never really took off in conventional road-going cars, but these machines did force other manufacturers to start looking outside the box. In 1967, STP CEO Andy Granatelli outfitted his team’s Indy 500 machine with a turbine engine taken from a helicopter, making it the first-ever turbine car to qualify for the race. Multiple teams took inspiration from Granatelli’s innovative idea by implementing turbine engines in their vehicles for 1968, but racing regulations tamped down innovation to the point where turbines were noncompetitive by 1969.

Bobby Unser and the 1972 Gurney-Eagle Olsonite Indy 500 record car,

The 1972 Indy 500 saw the greatest year-over-year increase in speed in the race’s history thanks to one key invention: bolt-on wings.

In the past, USAC (which sanctioned the 500) only allowed wings that were integrated into a car’s bodywork — but in 1972, it opened the rulebook to allow wings to simply be bolted onto the machine. That simple change saw a huge increase in downforce and a resulting increase in speed as cars were able to stick to the track more effectively, catapulting automotive design technology into a brand-new era.

But how effective were the wings? Well, in 1971, Peter Revson’s pole speed for the 500 was 178.696 mph. In 1972, polesitter Bobby Unser clocked a four-lap average of 195.940 mph.

Indianapolis 500 – The 1990s

Motorsport in general was something of a down-home affair throughout much of its history, but in the 1980s and 1990s, those down-home constructors who threw together a car in their home garage gave way to hyperspecialized teams dedicated to innovating in every possible way. Immense amounts of money were poured into racing development, and it resulted in Indy 500 machines being crafted out of carbon fiber and utilizing specialized forms of monocoque chassis. While American open-wheel racing did often lag behind Formula 1 in the technology department, these oval-specific construction innovations coincided with an incredibly prosperous racing era here in the States.