The STP Turbine Car: Almost Winning Indy Without Pistons

Ken Wallis Had Been Thinking About Turbines

Designer Ken Wallis had studied turbine-powered race cars and believed one could work at Indianapolis. A gas turbine offered some tempting advantages: relatively few moving parts, tremendous power for its size and smooth delivery without a collection of pistons changing direction several thousand times a minute.

It also eliminated the traditional racing pastime of inspecting a hole in the side of the block and identifying which connecting rod had decided to leave early.

Granatelli liked the idea. His brothers Vince and Joe helped turn it into a race car, STP supplied the money and enough lettering to make sure nobody forgot who had paid for it.

The result was the STP-Paxton Turbocar.

Everybody at Indianapolis called it the turbine.

The Engine Sat Beside the Driver

The powerplant was only the beginning of the odd decisions. Parnelli Jones sat on the right side of the car while the Pratt & Whitney ST6 turbine occupied the left.

Not behind him.

Beside him.

The chassis wrapped around both, and the turbine sent power through a Ferguson four-wheel-drive system. Four-wheel drive was unusual enough at Indianapolis. Four-wheel drive powered by an aircraft turbine sitting beside the driver’s elbow was making a stronger bid for attention.

The finished car was low, wide and impossible to mistake for anything else in Gasoline Alley.

It Didn’t Sound Like an Indy Car Either

An Offenhauser or Ford racing engine made the proper noises. Combustion pulses, exhaust bark and enough mechanical violence to reassure everybody that expensive machinery was working hard.

The turbine whined and whooshed.

“Silent Sam” became one of its nicknames, although silent was a generous description of a gas turbine operating a few inches from the driver’s shoulder.

Compared with the piston cars, though, the STP machine sounded less like an Indianapolis contender and more like somebody had entered industrial ventilation equipment.

That did not make the other teams feel better when it started going fast.

Parnelli Jones Needed Convincing

Granatelli wanted a driver capable of winning Indianapolis, and Parnelli Jones had already done exactly that in 1963. He was fast, experienced and not required to become enthusiastic merely because Andy Granatelli had discovered another piece of machinery.

Jones tested the car and found that turbines had habits.

Throttle response was delayed. Press the pedal, wait a moment, and then receive the horsepower you had ordered.

The engine also produced enough power at idle that Jones had to hold the brakes to keep the car from creeping forward. A conventional race engine responded to the driver’s foot.

The turbine accepted requests for future delivery.

Then Parnelli Learned What Four-Wheel Drive Was Buying Him

Once Jones learned to anticipate the turbine lag, the strange car began making a much stronger argument for itself. Power went to all four tires, giving the chassis tremendous traction while the turbine supplied smooth, relentless thrust.

Jones could get on the power early and let four tires share the work. The arrangement that looked excessively complicated in the garage became remarkably effective once the car was pointed toward Turn One.

The surprise was no longer that Granatelli’s turbine worked.

The surprise was how well.

Qualifying Didn’t Show the Whole Hand

Jones qualified sixth at 166.075 mph. Mario Andretti put his conventional Hawk-Ford on the pole at more than 168, so the turbine looked quick without looking terrifying.

There had already been plenty of muttering about how much performance Granatelli’s machine really had. Some competitors suspected the team was keeping something in reserve.

They did not have to wait long for an answer.

Sixth to First Before the First Lap Was Over

The 1967 Indianapolis 500 started on May 30. Jones left from sixth and reached the backstretch on the opening lap in first place.

Sixth to first.

One lap.

That reduced the number of people calling the turbine merely interesting.

The car did not have to scream through gears or ask two rear tires to process all the power. Jones got the turbine wound up, let the four-wheel drive hook everything together and left.

Rain stopped the race after 18 laps and pushed the finish into the next day.

The weather interrupted the demonstration.

It did not change the lesson.

On Wednesday, the Turbine Went Back to Work

When racing resumed, Jones took control again. The STP car was not merely competitive; it was dominating one of the biggest races in the world with an engine that had never seen a piston.

Jones built leads while conventional machinery disappeared behind him. The piston cars needed fuel stops. The turbine was efficient. They put power through two tires. Parnelli had four doing the work.

By late in the race, only A.J. Foyt remained on the same lap.

Jones had led 171 laps.

There was no longer much uncertainty about whether a turbine could win Indianapolis.

It was busy doing it.

Then a Caution Took Away the Cushion

With the race nearly finished, Gordon Johncock spun and brought out a caution. Jones had enjoyed a substantial lead, but caution periods have a nasty habit of returning advantages to people who had already lost them.

The field closed up.

The turbine was still running. Parnelli was still in control. Only a handful of laps remained, and Granatelli was finally staring at the Indianapolis victory he had spent years chasing.

With the strangest car in the place.

Then, on lap 197, the car stopped pulling.

The Turbine Was Fine

That is where the story becomes almost too tidy.

The Pratt & Whitney turbine had not exploded. The exotic aircraft engine survived nearly 500 miles. The radical chassis worked. Four-wheel drive worked. Jones had mastered the throttle lag.

The failure was a bearing in the transmission.

A bearing.

Jones coasted to a stop with three laps remaining after completing 196 laps and leading 171 of them. A.J. Foyt went on to win, while Parnelli was officially classified sixth.

Granatelli had brought an aircraft engine to Indianapolis and nearly beaten everybody with it.

Then an ordinary little piece of drivetrain hardware reminded the future that it still had to use bearings.

USAC Had Seen Enough

Competitors had questioned the turbine’s potential before the race. Watching Jones lead 171 laps did little to calm anyone who thought Granatelli had discovered too much advantage in one package.

Turbine performance was controlled through limits on air-inlet size, and USAC tightened those restrictions substantially for 1968.

Granatelli did not surrender immediately. He joined Lotus and Colin Chapman on the wedge-shaped Lotus 56 turbine cars, which also came close to upsetting Indianapolis with turbine power.

But the opening was closing. The regulations kept reducing available turbine performance until the concept lost the advantage that had made everybody nervous in the first place.

Nothing convinces a rulemaker that a technology deserves attention quite like watching it disappear into the distance.

Parnelli Never Drove Indy Again

The 1967 race became Parnelli Jones’ final Indianapolis 500 as a driver. He had won in 1963, finished second in 1965 and then dominated most of the 1967 race in machinery unlike anything he had raced before.

Jones later said he did not want to return without equipment he believed could win.

After leading 171 laps and losing with three remaining, his definition of competitive equipment had probably become inconveniently demanding.

The Crazy Part Wasn’t What Failed

That is the beauty of the STP Turbine story. It would be simpler if Granatelli’s experiment had collapsed because turbines were a foolish idea for Indianapolis.

They weren’t.

The aircraft engine worked. The side-by-side layout worked. The four-wheel drive worked. The unusual throttle response could be managed, and Parnelli Jones took the collection to the front of the Indianapolis 500 and kept it there for most of the race.

The radical pieces did exactly what Granatelli hoped they would do.

Three laps from victory, one ordinary transmission bearing decided the experiment had gone far enough.

Andy Granatelli almost won Indianapolis without pistons.

He still needed bearings.