Swoosh and screech! The rise and fall of alternative power in motor racing
Part 1: Aircraft on asphalt
- Mattijs Diepraam
- May 19, 2003
- Four-wheel drive - The Cosworth F1 car and the history of four-wheel drive in racing, by Mattijs Diepraam
- Lotus 56B - Aircraft on wheels, by Mattijs Diepraam
Click here to go back to the introduction
Turbines: the pros and cons
To see why turbine engines caught on quickly during the sixties, and moved over from road cars to racing cars, it is best to devote some paragraphs to explaining their internal workings.
First, let's give you the quick-and-dirty answer. The basis is formed by two turbines, the first of which is compressing air and forcing it into an ignition chamber (or "burner") with added fuel. The mixture of fuel and air will rapidly expand into a second two-stage turbine giving drive to the compressor turbine which is rotating on the same shaft (first stage, using 10% of generated power) and a single-gear transmission that is powering the car (second stage, using 90% of power).
It's as simple as that. It's no miracle invention, as turbines have existed for centuries. Indeed, water turbines had been driving mills alongside fast-streaming rivers since the middle ages, while steam turbines were among the most prominent power sources of the 19th century. So if "turbine" is the general denominator for a machine or motor driven by a wheel that is turned by the pressure of air, steam, water or gas, the innovation of the turbine car engine is in its application.
Now, let’s get to the nitty-gritty. What are its strengths and weaknesses? To start with the plusses: its simplicity is its main advantage. It is smaller than a piston engine. A 250hp turbine engine has a power turbine that is 4-5" in diameter, while the compressor turbine would be 7-10" in diameter. It also and weighs less, with 80% fewer parts. This naturally means less moving parts - no pistons, no valves, no camshafts, no cranks, no distributing belts! - hence less friction and wear, which results in negligible oil consumption and thus reduced maintenance. Futhermore, it is less susceptible to vibration due its rotary motion instead of the reciprocating piston movement. It will run on any flammable liquid or gas, from alcohol to peanut oil, from perfume to Jack Daniels, as the fuel's detonation characteristics don't really matter. It is in full working order from the start, as fuel is injected directly into the burner, with timing and vaporarization not critical at all. This in turn kills the need for a warm-up period - there is instantly available heat, instead of cylinder blocks and coolants needing to heat up first. Antifreeze isn’t needed either, as the temperature is controlled by the air flowing through the engine. Finally, the exhaust gases are cool and clean, with practically no carbon monoxide emission. And on the performance part – it's tough to kill a turbine engine by overrevving it, as the compressor rotates independently of the power turbine. Plus the rev count is unbelievable - up to 50,000 rpm!
On the downside, there is surprisingly little tricky stuff. The turbine had just one huge drawback: it guzzles fuel - up to eight times more than a piston engine. Early on, however, this problem was countered by using the first part of the two-stage turbine to not only drive the compressor turbine but also a pair of "regenerators". These honeycomb regenerators acted as a pair of clever heat exchangers, directing exhaust heat back into the system to lighten the burden of the burner, with fuel now only needed to raise the gas temperature up to the required level. As an added bonus, exhaust temperature was further cooled to safe heights. This resulted in the regenerative turbine engine that was to form the basis of all turbine-powered road and racing cars.
Turbines: the ancestry and the heritage
After a brief look-in by Opel in 1927, road-car turbines were separately pioneered by Rover and Chrysler, with GM and Fiat also looking into their capabilities. Rover started work in 1939, shortly after war was declared. This was on commission from the British government that amidst clouds of secrecy approached Rover’s Spencer Wilks to help out a company called Power Jets Ltd, which had a brilliant jet engine design but lacked production facilities. Chrysler latched onto the concept in 1945, but let’s start off with the British effort first.
Rover: true pioneers
The top-secret request to Rover came on the back of Rolls Royce’s lack of interest for the project, as they were in the middle of Merlin V12 production for their Spitfire fighter range. Indeed, the first application considered for the gas turbine developed by Power Jets’ Frank Whittle was aviation – and it being war, military aviation came to mind first, although for Rover mum was the word. The car manufacturer being the backup choice and uninvolved in aeronautics, Wilks left his engineers in the dark over the project, claiming that it was a new “supercharger” development…
Rover and Power Jets co-developed and produced two versions of Wittle’s original design, but they soon fell out as Rover made alterations – erm, improvements – to the W2 design and going another step further with the W2B, again without consulting Wittle. Rover had good reason, as the initial engines suffered from surging and turbine failure. Soon, with war now raging all over the continent, Rover managed to secure the government’s commission to go it alone. The new B-26 turbine was almost drawn on a blank sheet, and when Rolls Royce stepped into the turbine arena in 1942, the B-26 formed the basis of the Rolls Royce Welland, the world’s first production jet engine. So how did RR get their hands on the design? Well, basically that was Rover’s own doing, as their uncertainty over their future involvement in aviation left them do a deal with RR, which involved a swap between the Rover turbine designs and RR’s V12 Meteor engine, the Merlin follow-up that RR had developed for use in tanks. And so RR could stay the leading aero engine manufacturer, while Rover had their feet back planted firmly on the ground again.
The designs may have been sold, the knowledge had not gone with it. Only a couple of months into the post-war era the Wilks brothers had planned further turbine development for road car application. For this, Spencer Wilks made an approach to Leyland to help fund the project, while also luring away turbine engineers Frank Bell and Spencer King from RR.
Despite of immediate post-war material shortage a prototype engine called the JET 1 was up and running in February 1947. And although they had some steep hills to climb – like working out how to link a 50,000rpm turbine to the back axle of a road car! – a working fifth incarnation of the JET 1 was finished in May 1948. This had the aforementioned two-stage turbine solution to the drive problem that was later followed by other manufacturers, and produced 100bhp at 55,000 compressor rpm while weighing less than a Rover piston engine. A more powerful version was successfully tested in a boat at the end of 1949 and subsequently mated to a Rover P4 road car. On March 14, 1950, this car made its first runs and, as the “JET 1”, saw its first public appearance soon after.
The rear-engined JET 1 lit up at 3000rpm, with the compressor turbine’s speed at 40,000rpm and the power turbine maxing out at 26,000rpm. The idling speed was an impressive 13,000rpm! At 100bhp it got to 85mph at 6mpg. In 1952 an uprated JET 1 appeared, with a whopping 230bhp on tap, delivering a world record speed of 152mph, still at 6mpg. The same year also saw the advent and quick demise of an outboard engined turbine concept car, the T2A, which didn’t quite work as planned...
Four years later Rover was ready to announce its first car specifically designed around a gas turbine engine. The T3 was a Spencer King design, with help from Gordon Bashford and Peter Wilks, and boasted an two-shaft inboard rear engine producing 100bhp. It was a hugely innovative car that apart from the turbine engine was ahead of its time with its glass fibre body, De Dion rear suspension, back-angled front forks and 4-wheel inboard disc brakes. Also, turbine development had come a long way. Light-up was now at 15,000rpm, with the compressor’s working speed at 52,000rpm. By now, heat exchanger technology had seen the light of day, hugely improving fuel economy to 13mpg.
The regenerators were further refined to deliver 20mpg in the 1961 T4. This was a serious motorcar based on the Rover P6 (two years before the regular piston-engine P6 debut), as it gave an impressive 140bhp and had a 0-60 of 8 seconds. With a front engine, front-wheel drive and stunning P6 looks there was nothing to take away from it against the usual crop of piston-engine road cars. Still, Rover decided to leave road-car development for what it was and focused on racing their turbine engines.
Here’s a description by Graham Robson on the T4 road behaviour. ”Starting drill is simple but drawn out - turning the key actuates the special Lucas starter motor which winds away for several seconds. A faint, distant whine rises in pitch and intensity before light-up occurs and the engine settles down to 'idle' at 35,000rpm. This is enough to cause the car to creep along the road if the brakes are not applied, as there is about 4bhp residual at idle. To get moving engage forward gear and depress 'loud pedal' - after a jet lag of about 3 seconds, the engine speed rises rapidly to 50,000rpm and the car whooshes off up the road leaving engine noise behind (although this is quite acceptable to passers-by). 60mph is reached in 8 secs (a la 3500S) with very civilized handling.”
Although British road-car turbine development came to a halt after the T4, by this time, at the other side of the Big Pond, Chrysler was about to launch their first turbine road car…
Chrysler: real-world Parker and Penelope cars
The first design work on turbines at Chrysler had started as early as 1945. Over a decade of prodigious development got the company on the same level as Rover, with a single-shaft two-stage regenerating turbine engine that could be front-mounted, with the first-stage power turbine used to drive the compressor and accessory systems such as power steering, power brakes and even power windows!
In the early sixties ambitious plans were unfolded to produce an actual batch of cars to hand out to selected “test drivers” across the US. For this Chrysler designed a futuristic body that would be built by the famous Italian coachbuilder Carrozzeria Ghia. In 1963, the 55 cars were finished and shipped over to the States. Five cars were kept by the Chrysler development team themselves while in a grand sweepstake, with 30,000 people applying, 50 lucky people were handed out the remaining cars. This was done on the order of testing the cars and handing them back with a detailed evaluation.
In total, 203 average citizens got the chance to test the Chrysler Turbine between 1963 and early 1966. Most cars topped a trouble-free million miles before their retirement. The drivers ranged in age from 21 to 70, 180 were men and 23 women. They lived in 133 different cities in the 48 states. Conversely, car journos weren’t allowed any significant time in the car, and always with a factory representative in the passenger seat next to them.
The testers’ verdict matched the strengths that the designers had already envisioned and the weaknesses they had worked hard to eliminate: its operation was smooth and quiet, its reliability was staggering, but fuel consumption remained a worry. Then again, as Chrysler surmised, this was probably due to test drivers often showing off their Turbine in front of a crowd of impressed on-lookers. With an idle speed of 22,500rpm this would be fuel-consuming indeed! No wonder the drivers were sworn to secrecy about performance and fuel consumption… Other downsides were acceleration lag and the lack of engine braking, requiring a different driving technique altogether. When put in drive, it would have a basic speed in idle, like a piston-engine automatic. This required applying the brakes at all time.
However, its looks drew praise from all corners. The Chrysler Turbine was a car taken straight from the Thunderbirds – you could see Parker driving it, with Lady Penelope lighting a ciggy in the backseat. Amidst the usual early-sixties futuristic design pomp, there was plenty eye for detail, as the turbine theme was carried out all over the car: the headlights were surrounded by a jet engine air-intake motive, while the rear looked like a fighter airplane. The interior colour was called Turbine Bronze and boasted magnificent bucket leather seats and carpets, set off by fancy chrome touches. The console added the most drama, an brushed aluminium shaft being shaped as a turbine. Finally, the three-gauge dash was a stunner with the speedo maxing out at 120mph and the tacho showing a maximum 60,000rpm…
Low maintenance was definitely amoung the points that the test drivers raved about. Typically, the Chrysler owners manual confidently boasted a mere six preventive maintenance functions:
- Ensure proper fuel selection.
- Check level of hydraulic oil at each refueling.
- Maintain battery electrolyte level.
- Maintain windshield washer level.
- Maintain proper tire pressure (24 psi cold).
- Wash exterior and clean interior of car.
So that’s actually five preventive maintenance points!
Post-production: land speed record ‘cars’
Today, road-car turbines are fully a thing of the past and the legacy of its exciting age of development is now residing in museums – if they still exist at all. Happily, all of Rover’s great cars, bar the disastrous T2, were conserved and are now on display, the JET 1 in the Kensington Science Museum and T3 and T4 in the British Leyland Collection, in running condition no less.
Most of the Chrysler Turbines, however, awaited a much worse fate. This was due to US import laws, as the cars were fully built and assembled by Ghia in Italy. Thus US customs decided that import duties not only applied to the car but to its engineering and development costs as well, resulting in an astronomical amount of import tax. Eventually a deal was struck whereby Chrysler could bring the cars to the US for three years for selected customers to test. At the end of the period the company had to ship them back to Italy. Or scrap them. Which, under the watchful eye of the customs, was exactly what happened to 40-odd cars. Chrysler paid in full for ten cars to remain in the States, eight of which were sent to car museums, among them the Museum of Transportation in St. Louis. After a meticulous restoration during the late eighties and early nineties, the MoT example is the only running and publicly accessible Turbine left today, although eight others have survived to this day. Chrysler Corporation owns three of them. In 1977, Chrysler tried it one more time, with the Chrysler Le Baron Turbine, but again it was a shortlived project.
Although turbines thrive in the aircraft and helicopter environment, and are used competitively in offshore hydroplane racing, they haven’t disappeared from motorcar use completely. There is one very obvious category of cars left exploiting the technology – thrust-powered land speed record vehicles. These fastest of ground-based moving machines, such as the Thrust SSC, build on the experience gained in oval racing where top speed is of paramount importance.
Turbines: the cars and the stars
In 1961, after the T4 road car was successfully tested, Rover considered motor racing as a viable test ground for the turbine engines and created a partnership with the BRM racing team. The Bourne outfit had always been a team that would seek to exploit non-standard technologies – mostly to their detriment, as is seen by their V16, single inboard brake disc, 4WD and H16 engineering disasters – and so Tony Rudd’s crew were keen to help out, resulting in two Le Mans outings for the Rover-BRM turbine sportscar.
Other turbine-powered racing cars weren’t propelled by road-car manufacturer turbines, though. Their team owners and designers quickly switched to aero jet engine manufacturers for their turbine power, and so aircraft engines such as the General Electric T58 and Pratt & Whitney ST6 and STN76 found their way into several racing cars, such as Granatelli’s STP-Paxton Indycar, the Lotus 56 Indycar and 56B F1 car and the Howmet TX sportscar.
Rover’s link-up with BRM resulted in a first Le Mans entry in 1963, albeit hors concours – hence the 00 number that the car adorned. BRM provided their F1 drivers, giving the car a strong driver line-up in Graham Hill and Richie Ginther. The T4-engined sports prototype, nicknamed The Whispering Ghost, ran reliably at an average of 108mph (at 7mpg) and would have been classified 8th. In 1964 BRM entered officially but was a non-starter as the rebodied car (a job done by David Bache and Bill Towns) was damaged on transport to Le Mans.
Finally 1965 saw the car’s second and last outing at Le Mans. This time, the mods included increased air intakes and added driving lamps, and again BRM supplied its F1 driver phalanx, Hill now partnered by fast newcomer Jackie Stewart. In the race, the car suffered uncharacteristic engine damage but still it ran out the 24 hours, placed 10th overall at an average speed of 99mph and a reasonably fuel-efficient 13.5mpg.
Thus Rover-BRM’s Le Mans entry marked the turbine engine’s first competition effort. While the turbine movement petered away in Britain, it lit on in the United States at almost the same time. The obvious place for this to happen would be Indianapolis, as the world-famous oval track had become the natural shape for a whirlwind of innovations that put a violent end to the front-engined roadster tradition. As with the rear-engined “funny cars” and four-wheel drive, those “friggin’ Europeans” – or Brits, more precisely – had been the culprit, now importing turbine technology to the US, with STP’s Andy Granatelli in most cases acting as the main home-based catalyst. But the sportscar racing scene was to see another turbine-powered racing car as well.
Howmet TX sportscar
The Howmet TX Continental sportscar was conceived concurrently with the STP-Paxton Indycar, but made its debut one year later, as it was campaigned extensively in 1968. The original car, chassis 01, was built up from a McKee Can-Am car, with cars 02 and 03 specifically built for the turbine engines. The Continental TS325-1 helicopter engine, its calculated equivalent of 2958cc producing an approximate 330bhp, drew from a center-mounted fuel tank carrying 32 gallons of Jet A fuel.
It was designed for the FIA Group 6 3-litre prototype class through the sponsorship of the Howmet Corporation of America, a metal company working as a large subcontractor to the aircraft turbine industry. The man with the vision was sportscar racer-cum-engineer Ray Heppenstall, who convinced his racing pal Tom Fleming, a board member at Howmet, to start a publicity-gaining racing programme. As such the Howmet-Continental TX was entered for the World Sportscar Championship in the days it was still covering such glamorous events as the Daytona 24 Hrs, the Sebring 12 Hrs, the 6 Hr events at Brands and the Glen, the Targa Florio, the 1000 km events at the ‘Ring, Monza and Spa, and the Austrian Sportscar Grand Prix.
That year the season’s finale was the Le Mans 24 Hrs, delayed from June 15/16 because of French strikes in a politically heated summer period. The Howmet team’s Le Mans form wasn’t anything to go by, though, as the No.22 Ray Heppenstall/Dick Thompson car badly crashed out at Indianapolis corner in the 9th hour, with Thompson at the wheel, the car having run with a persistent fuel problem. The No.23 Bob Tullius/Bob Dibley car ran into wheel bearing problems that cost 3 hours to repair. After the car got running again, it was disqualified after 6 hours, having run an insufficient amount of laps. But before that they had scored some credible results, leading to a equal 4th place in the final 1968 International Manufacturer standings.
The season started promisingly, with the Heppenstall/Thompson/Lowther TX lining up 7th on the grid of the Daytona 24 Hrs in the spare car, after the 02 had developed engine problems during practice. With their 7th qualifying position they had beaten the works Alfas and the car was running as high as 3rd before Ed Lowther hit the wall on lap 34 because of the wastegate failing to open. At Sebring they placed 3rd on the grid, but again failed to finish as an engine mounting broke. Dibley replaced Lowther for the BOAC 6 Hrs but again a fine qualifying effort (7th) was thrown away with an accident early in the race – yet again a stuck wastegate had sent the car off the road, this time hitting a bank at Druids.
At this time the team shied away from the WSC trial to regroup back in the US. They skipped Monza – although it would have done well at the high-speed track – and were unsurprising absentees at the Targa, for which the turbine car would have been unsuitable anyway. They also skipped the ‘Ring and Spa events to concentrate on Le Mans, only to see the classic event postponed until late September. Instead, from May, the team ran a pair of cars in local SCCA events, starting with the Cumberland 200 where Heppenstall managed the car’s first finish. The Heart of Dixie race at Huntsville would become a glorious event, with Ray winning his heat and then the final. One weekend later, at Marlboro, Maryland, there were more wins, as Dickie Thompson won the qualifier and teamed up with Heppenstall to win the main 4.5 hour 300-miler, lodging the TX’s fourth straight win.
However, a return to the WSC at the Watkins Glen race in July saw the car’s finest, erm, 6 Hrs. Heppenstall and Thompson again teamed up in car No.76 while the No.67 car was raced by Dibley and Bob Tullius of later Group 44 Jaguar fame. Aided by the demise of two of the three factory Porsches, that both suffered failed wheel bearings, the two TXs ran reliably to the finish to take 3rd and 12th respectively, and four WSC manufacturer points. It could easily have been 3rd and 4th, as the Tullius/Dibley car had its transmission fail at the last gap. A makeshift repair allowed the car to limp over the line for a classified finish. Heppenstall/Thompson’s podium run meant a prototype class win too, as the top two places were taken by Ickx/Bianchi and Hawkins/Hobbs in Wyer’s two 5-litre Ford GT40s. However, they did beat the troubled remaining Herrmann/Izukawa Porsche (with Siffert also jumping in to salvage some points) by 12 laps.
Still it wasn’t enough for Howmet to commission a repeat season in 1969, but the cars were kept for other promotional uses such as taking a sextet of official FIA jet engine speed records on a straight near Talladega Speedway in August 1970. After that, Howmet agreed to sell the cars to Heppenstall, but were obliged to hand the engines back to Continental.
Today, car 01 with a dummy engine survives in the hands of a Californian collector. The second car ended up in the hands of enthusiast Chuck Haines, who entrusted its restoration to its original constructors, Chicago-based McKee Engineering, that placed an Allison turboshaft helicopter turbine in the empty engine bay. It has been seen at several historic events, debuting at Elkhart Lake in 1996 and also visiting the Goodwood Festival of Speed in 1998 and ’99.
The STP-Paxton turbine car that produced a heartbreaking near miss at the 1967 Indy 500 is the brainchild of Italian American Andy Granatelli, a racing nut who combined engineering vision with great business acumen. As a chief tester and engineer for Studebaker, Granatelli had always been a speed addict, having set over 400 land speed records. Among his engine designs are those of the Chrysler 300, the Cadillac Eldorado and the famous Raymond Loewy-designed Studebaker Avanti series. He then topped those achievements by stepping into the racing arena, buying out Lew Welch’s legendary Novi company and increasing its engine’s power output from 450 to 837hp. His business skills are best illustrated by the way he sold his supercharger business to Studebaker, bought them out of a run-down company called Chemical Compounds, changed its name to Studebaker Test Products (STP) and went racing with the STP Oil Treatment brand to gain big lashes of free publicity. From the acquisition in 1963 to the height of the brand’s fame less than a decade later, Granatelli built the company from seven to over 2000 employees. In 1974 he pocketed the money to purchase and grow another little-known company called Tune-Up Masters, to sell it again at astronomical value. Blatant self-advertising and the hard sell were in all cases responsible.
As an engineering enthusiast, having already brought Ferguson Formula four-wheel drive to Indy, Granatelli was quick to see the unfair advantage of a turbine engine matched with 4WD. Thus the STP-Paxton turbine car was born, with an FF 4WD system coupled to a reduction gear system supplied by STP’s Paxton division. It was built completely in-house by the Granatelli brothers, keeping it a secret from a competition as long as they could. As Granatelli told during an Indianapolis Legends interview in 2000: “Every single thing on the car except the wheels and the turbine engine was built in-house. Everything. And the reason we built everything in-house was because we didn't want to go to any outside vendor to have them know that we were building a special race car. And when we built the car, it was built completely in the rules, completely in specifications.”
Its engine was a Canadian Pratt & Whitney ST6B-62 rated at 550bhp – and it was mounted to the side of the car! In all aspects, the STP-Paxton shaped instant controversy. With its side-by-side construction it looked awkward – but still the driver’s weight counterbalanced the lightweight turbine. It was also quiet – hence the nickname of “Silent Sam” – and it was fast. Very fast. Soon the competition was complaining with USAC, which had already reduced the car’s turbine inlet area to 23,99 sq in. And there was more bollocking going on. Granatelli still gets mad thinking back to the car’s Indy debut: “We were told for example that the flap on the back of the car was distracting the other drivers. Bologna! It never distracted anybody. But they banned that first thing off the bat. With a piston engine, you take your foot off the gas, it's still through the crankshaft, but the compression slows the car down. But with the turbine car, you take your foot off the gas, and it's like putting the car in neutral. You keep going. So we needed something more in brakes. So we built a flap on the back of the car. When you stepped on the brakes, the flap would go up like an aircraft and slow the car down. Well, the drivers complained about that, not because it was too distracting, but to complain.”
“The drivers also complained there was terrific heat behind the car, that their cars were overheating and it was blinding them. They were choking. They couldn't see where they were going from the heat. That's all bologna and I'll tell you why. Mario Andretti, Bobby Unser and I were following the car around when Johnny Carson was driving it here during testing. And we got right up behind it with the pace car convertible, standing up on the top. It was like a balmy summer's evening. I said to Mario and I said to Bobby, ‘What are you guys talking about?’ ‘Well, we had to say something, ha ha ha.’ You know. There was no heat behind that car. There wasn't. Besides, just common sense would tell you that you can't heat up the whole atmosphere. You can't heat up the whole city of Indianapolis with one turbine engine.“
Nevertheless, and ominously if you weren’t part of the STP team, Granatelli had tempted legendary Parnelli Jones into racing it, and Jones, who was on the verge of retirement, was only willing to do that if he had a “lock on the race”. Granatelli was very convincing in his affirmation, and soon after the car was too – Parnelli found that it could go everywhere he put it on the track. Up, down, in the middle – the Swooshmobile didn’t need a “groove”. Amazingly, not a single modification was needed to achieve that, says Granatelli: “We never, ever adjusted a spring, a push-bar, nothing. We didn't change a thing on it. They didn't do a single thing to the car to make it handle it any better. They asked if the car was designed to handle it in the first place. It had equal weight distribution. It has center. It had the fuel tank down the center of the car forward, forward from front to rear. All the other cars since then and before then always had the fuel on one side or the other or on the back, but never all down the center. That's why I put the engine on one side and the driver on the other, because the weight would be equal all the time.”
Granatelli was so confident of its reliability that he didn’t even consider an engine change between qualifying and the race. He was right about that, but didn’t count on the Paxton gearing giving in. Having led 171 laps, Parnelli Jones coasted to a halt on lap 196 of 200 – with just 7.5 miles to go. It was truly the nearest of misses. The Swooshmobile had been running away with the race when a five-dollar bearing in the gearcasing failed, at a point where Parnelli had almost a lap in hand on his nearest rival, AJ Foyt – and that was after spinning earlier in the race and having to claw his way back through the field. “You know,” Jones remembered, “when I left the Speedway a couple of days later I felt bad. It was like I'd left home and knew I'd forgotten something, but couldn't remember what it was.”
The last-gasp loss didn’t help easing up USAC’s stance. Horrified by Silent Sam’s domination it changed the 1968 rules to further strangle the turbine’s inlet area to 15,399 sq in, bringing down its output to around 450hp. This is testimony to the complete package of his cars, Granatelli said in 2000, when asked about this tumultuous era of Indy racing: “Contrary to popular belief, the turbine car did not have a lot of power. It only had 480 horsepower while the other cars had 750 horsepower. But what the car did have was the ability to go along the corner anywhere on the track you wanted to put it. Under the groove, in the groove, under the white line, out in the gray stuff, it made no difference. The car could go wherever you pointed it. For those of you who've seen films on the race or those of you who were here when someone was driving a car, on the main straightaway, he'd go down, right down the side. He was breaking the car in. He didn't get out there in the groove at all. He drove it right down the wall. Well, that's the shortest way around the racetrack. The other poor guys wanted to go around the outside. We were driving all along the inside of the track, all along the track!”
Lotus 56 Indycar
The new-for-1968 air inlet rules called for a lighter car than the heavy STP-Paxton, and Granatelli found an ally in Colin Chapman, who had been watching the turbine development with great interest. In a meeting of two of the most innovative minds in world motor racing, the pair matched an uprated Pratt & Whitney ST6B-70 engine to the lightweight wedge-shaped Lotus 56, with sponsoring coming from STP. Here it is seen at its presentation at Hethel, with Graham Hill rolling out the car under Chapman's watchful eye.
The engine placement in the 56 was also offset – this time to the right, in order to make space for the 4WD drivetrain on the left – but this was covered up by the car’s broad appearance. Front and rear suspension used inboard spings and dampers, while the cockpit had a very finished and modern look. Through a Morse chain the turbine’s output shaft connected to a Ferguson centre diff behind the driver’s left shoulder. This was a development coming over from Ferguson’s road-car technology. The chain replaced the Paxton transfer gears, which had been the STP-Paxton’s achilles heel.
But before the race was on, the team was struck by double tragedy. First, Jim Clark died at Hockenheim. And then Mike Spence, the BRM number two lured over by Chapman to drive the 56 at Indy, was killed in a practice crash.
It didn’t stop the team’s eventual driver trio from occupying the first two places and ninth on the grid, with Joe Leonard and Graham Hill upfront and Art Pollard on the fourth row. Although Hill spun into the wall on lap 111, the turbines looked all set for a reprieve of 1967, only to come in for more heartbreak right at the end. Having been through one caution period to many, the leading Leonard car broke a fuel pump shaft on lap 192, with Pollard’s machine doing likewise only seconds later. What had happened? The drivers had been running at reduced power under yellow, and when they floored the throttle when the green was waved, the sudden load caused the extension shaft in the fuel pumps of both cars to snap. This was the result of Pratt & Whitney insisting on the heat-sensitive shafts carried over from their passenger aircraft engine technology. These would fail-safe under overheating and this proved their undoing during the yellow-flag periods. Before the race, this had been the subject of, let’s say, intense discussion between Lotus and P&W, with the eventual compromise that Hill’s car would run with a solid shaft and the two Americans’ cars with the original ones. If only Hill had been running to the end…
So, another narrow miss, and yet the USAC rules committee stepped in again. They’d seen enough, the turbines had to go. Granatelli is still amazed by the authority’s turnaround: “Well, first off, I was advised that I shouldn't run the turbine car, shouldn't build the turbine car. And I said, ‘Well, I don't care. The treble and pitch is right. I know what I want to do.’ And when I got here, everyone was flabbergasted. I received the all-time award, the Mechanics Award, for building the car and designing it. USAC officials went on paper and said it was 'the best engineered car' that ever went on the test and then within a couple of weeks, they banned it. So that's the way it goes, you know?”
In hot-blooded Italian fashion Granatelli started off a trial of lawsuits, which took the warring parties to the High Courts, with the sporting authority coming out unharmed for the plain reason that it chose not to follow the rules committee’s lead of banning turbines outright. Instead USAC cunningly slammed another restriction on the turbines. Short from actually banning them this rendered them useless for any further attempts at winning Indy. At the end of 1969, the death knell was further tightened by USAC’s ban on four-wheel drive, as this technology wasn’t held to be “within the mainstream of automotive development”. Oh, what poor vision… This meant an effective ban on turbines, too. This was precisely Granatelli’s accusation of USAC – that they had banned 4WD as a front to get rid of the turbines. He was probably right.
Meanwhile, the STP Lotus cooperation continued with Ford turbo-powered Lotus 4WD cars for 1969, and while on the eve of the Indy 500 an enormous row broke out between Chapman and Granatelli over the withdrawal of Hill and Rindt’s car, there was great satisfaction when Mario Andretti took an emotional Indy win in the team’s back-up Hawk. But that’s another story.
Lotus 56B Grand Prix car
It was probably the form the 56s showed during the rest of the 1968 season – on USAC road courses! – that convinced Colin Chapman to give the 56 a try in the Grand Prix environment. Here, four-wheel drive was still alive – probably due to its lack of success in 1969, as cynics might say. And so, after having emotionally dealt with the losses of Clark and Rindt, Chapman sprung a major surprise in 1971 by launching the Lotus-Pratt & Whitney 56B. Indeed, this was the turbine Indycar adapted to F1 regulations, with a 500bhp P&W STN76 engine.
It is said that the bulky 56B was only intended as a testbed for a sleeker turbine challenger to come in 1972, but the fact remains that Chapman’s driver diplomacy went awry in the same fashion as in 1969, when his beloved Jochen Rindt had publicly decried the Lotus 63 4WD car. This time, it was Fittipaldi and Wisell who took every opportunity not to drive it. And why would they when they had a totally sorted 72, now at its peak, waiting for them? This resulted in young Aussie Dave Walker taking the role that John Miles was forced into with the 63 – a junior driver being thrown into the deep end of developing and debuting an unloved car based on a revolutionary concept.
Granted, the team’s lead driver drove the 56B on its true debut, but this was a non-championship event that could be used for development without any harm. Moreover, Emerson left Brands Hatch seriously underwhelmed by the car’s potential in the dry. This was borne out by Wisell’s poor performance at Silverstone and by Fittipaldi at Monza, taking a black-and-gold liveried “World Wide Racing” 56B (the Italian investigation into Jochen Rindt’s death still in full swing) to the only finish (8th) in its short career. Mind you, this was pre-chicane Monza where the turbine shouldn’t have been outclassed by such a margin. But braking at Monza is much tougher than at Indy, which through the engine’s high idling strategy really hurt the car. Getting to the huge low-speed torque meant keeping the revs up, which resulted in enormous fuel consumption and thus a weight handicap – whereas the turbine was meant to be a weight saver.
In wet practice for the Race of Champions, however, Fitti managed setting the second fastest time. The same story applied to 56B’s World Championship debut, much later in the season when Dave Walker, having qualified at the back in 22nd, stormed through the field on a wet race day, the car working exceptionally well on the damp track. Within five laps the Australian was up to 10th, but then he overcooked it into Tarzan and slid off into the sand.
In Chapman’s mind it was an opportunity wasted. He blamed the weight and complexity of the car and wanted to pursue a rear-wheel drive version. In other people’s minds the wet-weather performances had all come because of the four-wheel drive, no thanks to the turbine. We will probably never know. In 1972 Lotus had a serious stab at the World Championship and all efforts were directed to helping Emerson win his first title. And so, Monza ’71 was not just the last we’d seen of four-wheel drive in F1, it was also the turbine’s Grand Prix swansong.
Go to part 2: The perfect gear
Book and Web references
- Gerard Crombac, Turbine Grand Prix
- Alan Henry, The 4-Wheel Drives
- David Tremayne, Futureworld: Will the piston engine ever be toppled from its current supremacy?
- John Wheaton, The Rover Turbine Cars
- Pete Stowe, The Howmet TX turbine car of 1968 - still the world's only turbine powered race winner
- The Concept Engine Site
- Allpar.com, the Chrysler’s Enthusiast Site
- The Indy 500
- Piston Heads: Turbine power history
- How Stuff Works: How Gas Turbine Engines Work?
The pictures with this article were mirrored from the above sites.