The Indy 500's greatest innovations: Lotus, Brabham and Penske

Indycar Racing News

From rear view mirrors to jaw-dropping engines, the Indianapolis 500 has seen plenty of innovations – James Elson picks out just a few

Jim Clark’s Lotus 38

Jim Clark's Lotus 38 – the first IndyCar to truly demonstrate the worth of the rear-engined philosophy

The 2024 Indianapolis 500 will be the 13th time the Dallara DW12 IndyCar – named after its late development driver Dan Wheldon – will be campaigned at the world’s fastest race.

In the name of cost-control allowing for a competitive field and the series’ economic sustainability, technological development has almost frozen at the Brickyard.

However, there was a time when innovation was the norm at the 500, with the performance advantage often being defined by some of the world’s most creative engineering minds.

Below, we go through some of the greatest technological breakthroughs made at ‘The Greatest Spectacle’ in racing.


Ray Harroun’s Marmon ‘Wasp’ – and the first rear-view mirror

Ray Harroun Marmon Wasp 1911 Indianapolis 500

Ray Harround and his rear-view mirror-equipped Wasp

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It’s understandable that when four-wheel forward motion was still being pioneered, few considered to look at what was behind them.

That began to change though with Ray Harroun’s WASP, which incorporated an innovative rear-view mirror into the first ever design to win at Indianapolis in 1911.

From the archive

The mirror took the place of the riding ‘mechanic’, as was typical at the time – and the car showed winning pace.

Though the WASP may look large and ungainly today, at the time its single-seater ‘fuselage’ body was innovative through its relative aerodynamic nature – a winning margin of 1min 43sec of Ralph Mulford’s Lozier proved as much.

With motor sport history starting as it meant to go on, competitors protested the Wasp, out of fear for its speed, but on the grounds of the apparent speed of the single-seater approach – but to no avail.

“With no one to warn him of overtaking cars, they claimed Harroun would be a menace on the course,” Motor Sport wrote in 2001.

He and relief driver Cyrus Patschke, whose mid-race burst of pace helped secure the win, were indeed – but only in the sporting sense as they claimed the first ever Indy 500 with a new innovation to boot.

Miller Special: The first rear-engined IndyCar

Over two decades before Jack Brabham shocked the IndyCar grid by setting the pace in his little rear-engined Cooper-Climax T54, innovative Henry Miller’s rear-engined machine became the first such prototype to make the 500 field, piloted by George Bailey in 1938.

The creative Miller saw a wide number of groundbreaking technologies make their debut at The Brickyard, including front and four-wheel drive, but it was rear-engined innovation which had the lasting effect.

Bailey would qualify the car sixth. Though he only lasted 46 laps, this was the furthest anyone of Miller’s several ‘back-to-front’ cars would go – until ‘Black Jack’ came along.

Jack Brabham’s rear-engined Cooper T54

Jack Brabham Cooper-Climax 1961 Indianapolis 500

Brabham T45 – not to AJ Foyt’s tastes

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While it may not have been the first rear-engined car to race at Indy, Brabham’s Cooper-Climax caused even more of a stir – mainly due to the results it garnered on track.

From the archive

IndyCar legend Roger Ward entered the 1959 US GP at Sebring, and was impressed by the ‘back-to-front’ T51 Cooper in which Bruce McLaren won the race and Brabham clinched his first world title.

He advised team boss John Cooper to bring a variation along to run on the bricks in 1961. Upon seeing it, AJ Foyt commented that it resembled “a bunch of pipes lashed up with chicken wire – I wouldn’t drive one of them no matter what.”

While the 2.7-litre car was 100bhp down on the front-engined roadsters, its impressive cornering speed indicated that this design philosophy could well be the way forward.

His ’61 debut qualifying position of 13th suggested as much, finishing ninth after making it up to third at one point.

Lotus picks up where Cooper left-off

Jim Clark’s Lotus 38

Rear-engined cars would prove to be the way to go after the Lotus 38

Two years later and Colin Chapman proved that Brabham’s results were no fluke.

As usual, the team boss had intent to innovate at the Brickyard: “I thought I’d travelled back in time and was watching a pre-war race,” he remarked after watching the race for the first time in 1962.

From the archive

Turning up with a green rear-engined Lotus 29 – considered an unlucky colour in American racing circles – Jim Clark qualified it fourth on debut, with team-mate Dan Gurney in 12th.

The reaction to a British team arriving with this unusual machine was unenthusiastic to say the least, as Shaun Campbell described:

“An American official told Lotus boss Colin Chapman: ‘Our drivers don’t feel good passing a green car,’ the only reply he got was a blithe: ‘I’m hoping they won’t get the chance.'”

Come the ’63 race, the pair worked their way to the front and at one point looked like they could be on for a shock win, with Clark ultimately finishing second to Parnelli Jones.

The following year the Scot took pole before crashing it, but it all came good with the Lotus 38 in 1965.

Clark started that year’s race in second, joined by Gurney in his own 38 and the previously anti-rear engine Foyt on pole in a 34 – when the lead Lotus driver went onto win, the revolution looked to have truly taken hold.

Lotus 56: gas turbine car nearly blows opposition away

Lotus 56 Graham Hill Vince Granatelli 1968 Indianapolis 500

Graham Hill in the gas-turbine Lotus 56

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Powered by the STP gas turbine, the Lotus 56 was practically spaceage compared to the rest of the Indy 500 grid when it made its debut in 1968.

That same turbine had been used to power the STP-Paxton turbine which came within laps of victory in 1967, but the Lotus version was a definite advancement.

From the archive

Just as arresting as its power unit and the hissing sound which accompanied it was the car’s wedge shape – some contrast to the usual cigar-form single-seater body which had become ubiquitous.

The car made up for power restrictions imposed on it by organisers with an advanced suspension set-up and its 4WD system, meaning it was closely matched with its competitors in the ’68 race.

Chapman and Maurice Phillipe’s design looked like it would win out in the hands of Joe Leonard though, until a fuel pump took it out from the lead with nine laps to go.

Governing body USAC would ban both turbines and 4WD – but Lotus had made its point.

VPJ-1: V-wing fighter fails to star

From an engineering triumph to a design oddity – Maurice Phillipe’s experimental car laboured at first, but by the end of its 1972 debut season it had helped secure the third consecutive IndyCar title with Joe Leonard at the wheel.

However at its birth the car had two pairs of ‘V-wings’ in a creative bid to generate more downforce – but it didn’t convince then-double champion Al Unser Sr:

From the archive

“Maurice Phillippe joined Vel and Parnelli, and that’s when the nightmare started, when that ‘creation’ happened,” he remembered in 2002.

“That ‘dihedral wing’ car wouldn’t work. I finished second in 1972, but if it had been the car it should have been, I might have given Donohue a decent run.”

It wasn’t just the wings which were innovative. Large ducts were carved into the radiators and the rear brakes were inboard, linked to rising rate suspension.

However, though the wings were tested during Indianapolis 500 practice, no discernible benefit was found and they were ripped off long before the big race at the end of May.

Chaparral 2K: Indy 500’s first ground-effect winner

Johnny Rutherford Chaparral 2K 1980 Indianapolis 500

Johnny Rutherford in his yellow Pennzoil Chaparral 2K, with Mario Andretti centre and Bobby Unser on the outside

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The Lotus 78 and 79 brought the ground-effect sea-change to F1, and Jim Hall in the US wanted a piece of the action in IndyCar.

He hired young designer John Barnard to pen the Chaparral 2K, who drew the car in his father’s front room.

From the archive

“Gordon Kimball came over to work with me and it was one of those projects that seemed to work perfectly – everything we drew fitted at the first time of asking,” he told Simon Taylor in 2018.

“The car was built up around a dummy DFX and then flown to Chaparral HQ at Midland, Texas, where a live Cosworth was fitted. Our engine guy, Franz Weis, took the car around this funny little local track, Rattlesnake Raceway, then it went off to test at Ontario. Out of the box, in Al Unser Sr’s hands, it just ran and ran. From there it went straight to Indy.

“I flew back to the UK to oversee the building of a second car, as a spare, and missed qualifying. As it was Al put it on the front row, in third, but if I’d been there I’d probably have made a few more set-up changes and would like to think it could have been on pole.”

Unser would lose out due to gearbox problems in ’79, but a year later Johnny Rutherford would clinch a famous first ground-effect victory at Indy.

Penske’s monster Mercedes engine dominates Indy

Emerson Fittipaldi Penske-Mercedes 1994 Indianapolis 500

Fittipaldi dominated in 1994 Penske-Mercedes – but team-mate Unser Jr won

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In 1994, Penske, Illmor and Mercedes shocked IndyCar.

Its 3.4-litre V8 turbo obliterated the field with a 200bhp advantage, with drivers Al Unser Jr and Emerson Fittipaldi reaping the benefits.

The single-camshaft design went against winning convention (which was a four-camshaft option), but had shown potential after Gary Bettenhausen took Indy 500 pole in a turbo Buick-powered Lola, while the next year Roberto Guerrero claimed fastest qualifying time with a similar car.

“Time after time we kept seeing the Buicks running fast and blowing everybody off for pole, but then they’d break down in the race,” Roger Penske told Gordon Kirby years later.

“So I talked with Mario [Illien] and said, ‘Why don’t we look at doing a pushrod engine?’ And he said, ‘Absolutely.’”

From the archive

“After the 1993 Indy 500 USAC freed up the rules for the pushrod engine,” said Mario Illien. “The only limitation was the capacity and a single camshaft with pushrods and rocker arms. I had done some homework and was confident we could get well over 900bhp.”

Unser Jr took ’94 pole while Fittipaldi started third, but in the race not only were the Penske’s more powerful – they had another advantage up their sleeve too.

“Most of the other teams didn’t have a chance because they had to make more pitstops than us because of fuel consumption,” said Illien. “We produced 1024bhp with the race engines and also made great fuel mileage compared to everyone else.”

Fittipaldi would dominate most of the race and lap almost the entire field, but then ironically crash out while trying to lap Unser Jr – who was left to take an easy win. And then USAC ultimately outlawed it.

“That was probably the last of the projects at Indy where you could innovate,” said Penske’s general manager Clive Howell. “After that everybody started running more of the same stuff. The original ‘run what you brung’ innovative attitude of the Indy 500 has gone.”