The Chrysler Patriot: Turbine-Powered Hybrid Racing Car — Future of Formula 1 Racing
The Patriot was briefly and heavily hyped, but was then dropped without fanfare. This is the story of its life and death, from two very different viewpoints.
In 1992, Chrysler engineer Ian Sharp was hired by Chrysler from a job in the UK racing industry; he was assigned to Jeep for a year, and was then asked to join Liberty Technical Affairs in Sterling Heights, Michigan, a department run by Mr. Tom Moore.
While at the Liberty group, Ian led a group to Reynard and Lola to review carbon fiber materials and build technologies. After the trip, Ian worked on evenings and weekends, researching and formulating ideas, and one Saturday, after about three weeks of work, he presented a copy of his proposal to Francoise Castaing, the head of engineering. The proposal was for a hybrid Le Mans race car.
Ian was subsequently asked to present his ideas to the motorsports committee that had been formed at Chrysler by Francois Castaing, under Bob Lutz's guidance. (Ian still has copies of his proposal for a historical perspective, along with package studies for an F1 Williams, using 1991 Williams F1 drawings acquired from his contacts there.
The main elements of the proposal were:
- Turbine Generator as the heat energy source. (Originally Williams TS 117 engine)
- LNG as the fuel source (suggesting a consortium of Brunswick, Northrop, and NASA; Ian was working with Dave Sherrill of Northrop et al.)
- Flywheel energy storage as the electrical load leveling device for transient electrical absorption and delivery of power to and from the traction motor.
- Westinghouse Electrical motor drive (considered as a 4 wheel drive with two motors, using split electrical motors as electronic limited slip differentials).
- Reynard under the guidance of Mr. Paul Brown was recommended to build the car.
- J&P Motorsports in Atlanta Georgia was recommended to run the car and conduct assembly in the USA.
- A delegation be dispatched to T. Boone Pickens in Texas, who had extensive interests in natural gas.
The regenerative braking would cut brake wear and fueling stops, so there was less time spent in the pits. The goal was both to win the race outright, and to win the Le Mans Performance Index given each year to the car with the best economy performance.
The originally specified turbine generator unit was from Williams Engineering, in Michigan. Later, in the final proposal, Ian changed it to Allied Signal, from their advanced military engine unit; he was working with a Richard Bonnis there. The TG unit being offered to Chrysler, before the corporate Chrysler engineers got involved, was a foil air bearing unit which was just going to be introduced to the military for a new helicopter. The foil bearings meant there was no cooling requirement for the turbine generator unit; the air was drawn through the generator to cool it and heat the incoming turbine charge. The unit only switched on to power balance the whole system and ran at a constant energy efficient speed.
Transient power delivery and brake regeneration absorption was accomplished by the flywheel. The holy grail of all race cars is to remove or reduce the use of radiators (aero drag) and this concept went almost all the way to achieving that. However, the power electronics still needed cooling, and this was accomplished by using waste heat to gasify the LNG for delivery to the turbine.
LNG was proposed as it had an energy density that closely resembled petroleum spirit (gas). It was and is abundant in the United States, and is a clean burning fuel. Brunswick was the proposed cryogenic tank builder.
The flywheel was to be from Unique Mobility. Westinghouse was contacted to supply a (500hp) motor, from the Sea Wolf submarine being built by the Electric Boat Company. Reynard was the vehicle integration system designer into a sportscar chassis design.
Ian Sharp, because of his friendship with Julian Randles, suggested J&P be the builder, under contract to Chrysler. With the demise of the Patriot project, J&P, under guidance from Chrysler and Reynard, developed the first Viper for racing, making the Viper 90% race ready, including a complete aero package.
Ian was removed from the Patriot project before being able to see it to completion (he wrote, “due to egos in senior management wishing to lay claim to the program, poor engineering decisions which he did not agree with, and corporate politics”), and the project took on a life of its own as engineers not versed in top class racing drove the project in a direction that could not be successful.
(Ian thanked Matt Weber, now of Harley-Davidson, whose engineering helped; and Gil Chapman, Ken Mack, Tom Kizer, and Dr. Chris Borroni-Bird, helpful sources as he researched the project).
Ian wrote: “When the Patriot was going awry, Matt and I used CATIA and packaged a Williams FW14 Formula 1 car with the Patriot system, and it fit very neatly.”
Ian Sharp had specified an Allied-Signal engine, and had a commitment from Allied Signal to provide five engines, free of charge, with a crew to maintain them. They were state of the art and ideally sized, with the right weight and power. Ian wrote that the corporate people chose another company with little turbine experience, SatCon, because they were part of Ingersol Rand; as Ingersol Rand’s air tools were used on the assembly line, they already had a supplier code (“the terrible process of getting a supplier code through Purchasing and Finance made the engineers tear their hair out.”) SatCon claimed 30 engineers were working on the project, but Ian wrote that J&P, which had engineers at SatCon, only ever saw two engineers at a time working on the project. They billed Chrysler about $12 million for work never completed [a record from 1993 shows $4.1 million but the project was still ongoing]; but, again, Chrysler could have had 5 free state of the art engines from Allied Signal. SatCon did apparently provide a compact transformer “off the Seawolf program,” according to Lee Carducci.
Nearly twenty years later, Formula 1 has requested proposals for kinetic energy recovery systems on F1 cars for 2011, and the likely winner will be a similar flywheel system. If ratified by all the teams, it will become standard in 2011. Ian wrote, “[This is,] in my estimation, the future of onboard energy recovery, not batteries or supercapacitors. The system in question is connected directly to the transmission, is not affected by temperature, is light, and very cost effective.”
- Power 60 kW (80 BHP)
- Storage 400 kJ (6.7s at full power)
- Weight 25 kg (55 lb)
- Efficiency > 70% round trip
- Dynamic response zero to full power in 50 ms
- Flywheel speed 64,500 RPM Max
- Flywheel weight < 5 kg (11 lb)
“The Patriot also had an air bearing turbine generator unit — and Formula One has received a proposal to introduce a turbine as an alternative engine type.”
Evan Boberg, in Common Sense Not Required, wrote that the Patriot was doomed by its dependnece on a massive flywheel; there was no way to protect the driver from a catastrophic flywheel failure without making the Patriot too heavy (some electric buses use flywheels for short trips without wires, but they have appropriate, and heavy, shielding). He also wrote that the Patriot never actually worked and had to be towed in its video (the tow truck, he said, was edited out); to be fair, this would be after Ian Sharp had left the project, and does not reflect on Sharp’s work. Boberg also said that the flywheel - holding nearly the kinetic power of a truck at 100 mph - had destroyed several test cells in an experiment designed to cause failure of the flywheel.
The Chrysler Patriot hybrid-electric racing car as built
The Chrysler Patriot was a hybrid-electric, turbine-powered, liquid natural gas-fueled racing car for racing; the company said it could reach 200 mph for short durations, with competitive handling. The powertrain included a two-turbine alternator, an ultra-high-speed flywheel and an electric traction motor. All components were water-cooled.
The traction engine was a four-pole, three-phase, 525-volt AC induction motor, weighing 143 pounds, with a maximum speed of 24,000 rpm; it had an aluminum housing, was lubricated by oil, and had an 8:1 motor to final drive ratio.
The turbo-alternator was a compounded twin-spool turbine with two alternators, fuled by natural gas, with a 100,000 rpm high speed and 50,000 rpm low speed; an intercooler was placed between the low and high speed compressors. A single point combuster was used; the alternators were three-phase AC induction. The whole thing weighed 186 pounds and was water-cooled; materials used included composites, ceramics, titanium, and stainless steel.
The flywheel system weighed 1147 pounds, and was vacuum housed; it could spin up to 58,000 rpm on its gimbaled mounting. The motor had three-phase permanent neodymium iron boron magnets in a Halbach array. The rim and housing were made of carbon fiber; the bearings were mechanical.
The chassis was built in England by Reynard to compete in the new World Sports Car (WSC) class co-conceived by the FIA, which overseas motor racing around the world from its headquarters in Paris, and the International Motor Sports Association, the premier U.S. road-race sanctioning body. The WSC is a prototype class intending to attract cars at the cutting edge of design and technology.
Chrysler’s 1993 press materials around the Patriot hybrid
Car makers commonly race hoping a win on Sunday will boost their dealers' sales on Monday. But Chrysler is contemplating returning to racing to learn how to better build fuel-efficient, low-emissions cars that are still fun to drive.
"When it comes to forcing technology and engineers, nothing equals the pressure cooker of motor racing," explains Francois J. Castaing, vice president of Vehicle Engineering at Chrysler. "Going back 40 years, motor racing helped invent some of the technology that we depend on today for safety and emissions -- such as disc brakes and fuel injection.
"We still believe there is a vital role for racing to help push technology where its needed." To this end, Chrysler will design and build in 1994 a hybrid-powered, liquefied natural gasfueled race car with an eye to entering the car in select internationally significant endurance races in 1995.
The chassis is being built in England by Reynard, one of the most successful race car builders in the world. Reynard will also debut this year at the Indianapolis 500 with several cars, one of which will be driven by Michael Andretti. The Patriot would compete in the new World Sports Car (WSC) class co-conceived by the FIA, which overseas motor racing around the world from its headquarters in Paris, and the International Motor Sports Association, the premier U.S. road-race sanctioning body. The WSC is a prototype class intending to attract cars at the cutting edge of design and technology.
The Patriot's hybrid powertrain will, its designers are confident, permit the car to run with the leaders of the WSC pack. This means reaching speeds in the neighborhood of 200 mph for short durations. And, although without disclosing specifics -- most of the elements of the car's powertrain are proprietary -- its developers are equally certain its drivers will not be left choking on other race cars' exhaust when exiting even the slowest corners.
Comprising the car's one-of-a-kind, experimental powertrain are a two-turbine alternator, an ultra-high-speed flywheel and an electric traction motor. All of these components are currently in operational use in some form -- turbine alternators provide electric power to commercial airliners parked at jet-ways; energy-storing flywheels can be found in many common-place applications; and electric traction motors drive some of today's zeroemission evaluation cars.
But the key to the Patriot's potential as a race car, and ultimately the commercial clean air viability of its hybrid powertrain, is its vehicle management controller. Much like the overmythologized little black box, the electronic controller will do what's never been done before in coordinating and directing the transmission of power between and among the turbine alternator, flywheel and motor.
Using sensors placed around the car, the controller will always be prepared at an instant's notice to send the demanded amount of power from the most qualified and ready source in the needed direction. This could be from the alternator and flywheel (in effect, an electro-mechanical battery) to push the car to top speed on a long straight. It could be from the motor back to the flywheel during hard braking at the end of the straight to "recharge" the "battery." Or it could be from the flywheel to the motor to propel the car back up to speed out of a slow corner. Whichever the case, the controller constantly will be picking and choosing the proper sources and destinations for the various power flows.
As Castaing noted, it is, in fact, precisely the highly dynamic power demands intrinsic to road racing that make it the ideal proving ground for the Patriot's hybrid powertrain. This is because a hybrid powertrain puts to best use the energy from its fuel source when it's operated in a repetitive acceleration and deceleration setting. Also, by entering the Patriot in endurance events, Chrysler expects over the duration of a 12-or 24-hour race, it will find weaknesses and build on strengths in the hybrid powertrain that could otherwise take weeks, months or even years of regular testing and development.
If the Patriot is successful, people wanting cleaner cars to drive into the 21st Century will not be the only beneficiaries. Motor racing, too, will reclaim some of its heritage as a proving ground for tomorrow's technology.
Chrysler Corporation does not believe tomorrow's ultra-efficient and ultra-clean car has to be either slow or boring to drive.
This optimism has the company considering going motor racing again in the international arena with a multi-year project to design and build a hybrid-powered race car that meets FIA World Sports Car class specifications. If the project, called Patriot, develops as Chrysler's top officials and engineers hope it will, the company will consider entering select high-profile endurance road racing events in 1995 as part of the development process.
"Chrysler has been anxious to go back to top-level racing for some time," says Francois J. Castaing, vice president of Vehicle Engineering at Chrysler, "but we wanted to send two specific messages when we did. We wanted to be able to reconcile our research on environmental issues with racing - a subject many people have talked about. And we wanted to use racing once again for the purpose of developing all-new technology that will test the creativity and ingenuity of our people. The Patriot lets us do both."
The new technology Chrysler is looking to the Patriot project to sort out is a complex hybrid power train system.
The resurgence of interest in hybrid powertrains in recent years for use in automobiles grows out of a potential to be both more efficient and cleaner than the gasoline- burning internal combustion engine. It is this potential that has made hybrid systems a candidate for powering the Super Car the federal government and U.S. car makers have committed to develop by the early 21st Century.
Although hybrid systems themselves can be quite complex devices, the theory behind them isn't. The cleanest and most efficient internal combustion engine is one designed to run at a constant speed. Put another way, the more the engine has to accelerate and decelerate, the more fuel it consumes and the dirtier its exhaust.
Dedicating an internal combustion engine to running a generator lets the engine operate at an almost constant speed. The electricity from the generator, then, is the" fuel" that powers the car. In automotive applications, hybrid systems also incorporate a battery, either as the primary power source driving the car's electric motor or as a supplemental power source when the generator cannot provide all the power needed.
Another benefit of dedicating the internal combustion engine to running the generator is that the engine operates only when the battery or the car's motor needs electricity. More advanced hybrid systems also reclaim energy generated when the car is braking to recharge the battery.
As promising as hybrid systems may sound, they do have drawbacks. At their current state of development, they are expensive, comprising as they do two powerplants; the internal combustion engine and the generator. The electronic controller that routes power where it is needed, precisely when it is needed, and from the best source, is both complex and far from cheap. Long trips driven at relatively constant, high speeds are also not a hybrid system's strong point. They work best (that is, get the most out of the fuel they consume) in stop-and-go driving, when power demands rise and fall and when braking energy can be reclaimed. This is why the Patriot will race, if it does, in endurance road races and not on high speed ovals.
They also are not zero-emission vehicles. Run on the proper fuel, however, which, in the Patriot will be liquefied natural gas, they can be ultra-low emission vehicles and fuel efficient. The system will also make the best possible use of that fuel's energy, both in generating and storing the electricity produced, and by reclaiming energy that would otherwise be lost as heat generated during braking.
These limitations on hybrid powertrains' benefits need to be understood, Castaing says, to make sure Chrysler's Patriot project is not misunderstood. The Patriot is independent of the company's work with federal and state clean air regulators on the low and zero emissions cars for California and the Northeast States. And while it may eventually be related to the Super Car venture, that effort is evaluating other powertrains as well.
Chrysler also believes it is breaking new ground with the team of internal and external experts the company has assembled to work on the Patriot project.
The car will be built in Bicester, England, by Reynard, a well-known builder of championship winning cars for the FIA's Formula 3 and Formula 3000 classes. Reynard will also debut this year at the Indianapolis 500 with several cars, one of which will be driven by Michael Andretti.
A twin-turbine turbo-alternator will power the Patriot. The turbine unit comes from Northern Research and Engineering Corp., of Wobrun, Mass. NREC is highly regarded in the defense industry for its work on nuclear submarines and helicopter jet engines.
The assembled turbo-alternator and the carbon-fiber flywheel, which will serve as an electro-mechanical battery for the Patriot, will be made by SatCon Technology Corp., of Cambridge, Mass. SatCon designs and builds motion control systems, sensors and actuators used in weapons systems and satellites.
Cryogenic Experts, Inc., of Canoga Park, Calif., has signed on to build the storage tank for the liquefied natural gas that will fuel the turbo-alternator. The work CEXI has done on such NASA projects as the national aerospace plane, and with Lawrence Livermore National Laboratory, qualify the company to tackle the job of building a crash-impervious fuel tank that can keep the LNG at its required minus 258 degrees F storage temperature.
Westinghouse Electric Corp., of Baltimore, Md., will provide the traction motors that will get the Patriot's power to the road, driving the car, if the theoreticians are correct, to speeds in excess of 200 mph.
In the spirit of the platform team concept that has produced the award-winning cabforward Chrysler, Dodge and Eagle sedans, Dodge Ram pickup and Neon, Chrysler engineers and designers from the environmental field, the high-performance area, and the future car research group -- "people who traditionally are not likely to work together," Castaing notes -- are joining forces with a small group of key suppliers to see if it is possible to build a "socially responsible" car that is also fun to drive.
Thanks to J.P. Joans for supplying the press materials this article was based on.