Jaguar gears up to produce small run of turbine-powered C-X75 supercars
02-08-12, 08:25 PM
#1
Jaguar gears up to produce small run of turbine-powered C-X75 supercars
Jaguar gears up to produce small run of turbine-powered C-X75 supercars
Gallery:
http://www.autoblog.com/photos/jagua...photo-3414388/
Jaguar has a bit of a tricky history with supercars. The only previous example it actually built was the XJ220, which remains an impressive specimen even 20 years later, even though it never quite lived up to what the original concept car promised those who put down their deposits. Then in 2010 the British automaker unveiled the C-X75 and our hearts stopped.
The show car packed an intriguing twin-turbine powerplant into an alluring svelte shape, which only begged the question: would Jaguar build it, and if so, would it incorporate such an experimental propulsion system?
We had what we thought was the full answer last year when Jaguar announced that it would indeed produce the C-X75, but that the turbines wouldn't make it to the road, replaced instead by a hybrid drivetrain including a turbocharged four-cylinder engine. Disappointing, sure, but a little less so considering that the Williams F1 team would help develop the powertrain.
Now it seems that, while the hybrid turbo four will power most of the 250 examples of the C-X75 earmarked for production, a limited quantity will actually include micro-turbines as envisioned in the concept car. The jet engines (which will drive the rear wheels, so don't go expecting flames shooting out the back, Batmobile style) are reportedly being produced by the Bladon Jets Engineering Centre in Coventry – a company based near Jaguar's headquarters and partially owned by Jaguar's parent company Tata.
Although the turbines are only expected to produce 95 horsepower each (they are just a bit smaller than the ones you might find in a jet airplane), they need none of the cooling or lubrication systems required by traditional internal-combustion engines, leaving them lighter and easier to package – and making plenty of room for additional electric power to help the turbine-hybrid C-X75 hit 60 in just three seconds while returning exceptional fuel economy and emissions figures.
It'll be a few years still before this super-cat hits the road, but when it does, we're looking at something that will re-write the rule book even more than the XJ220 that came before.
http://www.autoblog.com/2012/02/08/j...ered-c-x75-su/
07-26-12, 03:53 PM
#3
Much has been said about the upcoming C-X75 from Jaguar, but now we have some real, tangible news. The hybrid supercar will be fitted with a 1.6-litre turbocharged inline-four capable of, apparently, 500 horsepower.
According to Autocar, the diminutive engnine is able to acheive this output through twin-charging, or the employment of both a supercharger and turbocharger. They are able to boost power at varying RPMs, thus making for a wide powerband. Oh, and speaking of revs, the engine is said to redline at a towering 10,000 RPMs.
Jaguar engineers estimate that the eco-friendly performance machine will achieve a top speed of 322 km/h (200 mph), and 0-100 km/h time of below three seconds. That should put it in the same neighborhood of the forthcoming McLaren P11 and Porsche 918 hybrid-supercars. Jaguar is developing the C-X75 with Williams, and intend on producing only 200 examples. The first of which is said to roll out in 2014.
The supercar never runs on gas alone, as the mid-mounted four-pot constantly charges up the 600-volt battery pack. The battery sends power to a pair of electric motors that allow the vehicle to run in full EV mode at speeds of up to 40 mph.
The price for all of this high-tech low-emissions gadgetry? £700,000 to £900,000, or $1.1 million to $1.4 million based on current exchange rates.
According to Autocar, the diminutive engnine is able to acheive this output through twin-charging, or the employment of both a supercharger and turbocharger. They are able to boost power at varying RPMs, thus making for a wide powerband. Oh, and speaking of revs, the engine is said to redline at a towering 10,000 RPMs.
Jaguar engineers estimate that the eco-friendly performance machine will achieve a top speed of 322 km/h (200 mph), and 0-100 km/h time of below three seconds. That should put it in the same neighborhood of the forthcoming McLaren P11 and Porsche 918 hybrid-supercars. Jaguar is developing the C-X75 with Williams, and intend on producing only 200 examples. The first of which is said to roll out in 2014.
The supercar never runs on gas alone, as the mid-mounted four-pot constantly charges up the 600-volt battery pack. The battery sends power to a pair of electric motors that allow the vehicle to run in full EV mode at speeds of up to 40 mph.
The price for all of this high-tech low-emissions gadgetry? £700,000 to £900,000, or $1.1 million to $1.4 million based on current exchange rates.
07-28-12, 01:19 AM
#7
Out of Warranty
Small but important point here, there is a monumental technical gulf between a twin-turbo four and an actual gas turbine engine. Chrysler, GM, and more recently Jay Leno have sunk many millions of dollars into a gas-turbine car, but while some characteristics of a turbine engine are hopeful (light weight power, high reliability) there are significant problems for automotive applications:
By the time you've added a high-volume muffled exhaust, large filtered intakes, ceramic heat exchangers, big transmission, big brakes, and a moderately large fuel tank (You'll be lucky to get 14mpg out of the rig), you've put back all of the weight, cost, and maintenance you were trying to avoid in the first place. No, driving the wheels by means of a gas turbine still isn't practical.
But there is a ray of hope: there may be a place for a small gas turbine in an electric vehicle like the Volt. Running a tiny turbine at constant speed to drive a high-capacity alternator would pretty well solve all the above problems. While accessories would still be of formidable size, a turbine spool that would fit in a shoebox could turn up an alternator that could furnish some pretty serious kilowatts. These micro-turbines, fueled by natural gas are running small electrical plants for remote oilfield pumps and pipeline pumping stations deep in the boonies with very minimal maintenance and no reliability issues. Most of these units fit in a building about the size of an executive desk, and are pretty quiet, even only ten feet away. A unit that size (most of which is sound-deadening material) can easily power a home with up to 15 kW.
A turbogenerator producing only about a third of that could maintain an electric car's battery once the vehicle has put on sufficient miles to require an electrical boost.
Reliability of a gas turbine is legendary - Solar Gas Turbines used to joke that their products were guaranteed for 100,000 hours, or one start. They were intended never to be shut down - which induces serious thermal stress on the turbine, seeing as it is primarily cooled by its own intake air. They could be shut down by turning off the fuel and "windmilling" the turbine with the starter at about 20% for several hours.
With one of these turbine-electric vehicles in your garage, you could plug your house into your car and get off the grid altogether.
- Turbine engines want to run at constant speeds. This is where they get their fuel efficiency and reliability. Constant jockeying of the throttle, required for on-road use creates havoc with heat loads, fuel efficiency, and power transmission.
- Gas turbines are extremely noisy, requiring large, complex systems to both quiet and cool the large volumes of expanding gas that pour out of the exhaust. With exhaust gas temperatures four or five times higher than those from a piston engine, the exhaust stream has to be cooled before it melts the tarmac or the bumper of the car behind.
- With the gas producer (compressor) turbine turning in excess of 22K RPM in most jet engines, there are considerable forces at work that demand intake air not contain gravel, roadside trash, or small birds or woodland animals, that can damage or remove a turbine blade, that projectile will then remove the next two, then four, then eight, then the engine explodes. Foreign object damage (FOD) is the bane of jet engines everywhere.
- Gas turbines require a large battery - or a starter cart, to get them going. Most turbines have to get up to 80% (rpm) before you can turn on the fuel and hit the ignitor. That's going to be a long groan for your on-board electrical system.
- Although gas turbines can produce plenty of power for their weight, there is that matter of a transmission. First, it's probably best to allow the engine to run at a constant speed while you accelerate and decelerate using either a "hydrostatic" drive as in a tractor, or a CVT. Either way, without engine braking and plenty of "whoa" applied to control the "go" service brakes are going to need to be massive. Chrysler developed a variable-vane turbine in the early sixties that allowed the engine to vary power output over a suitable range that it could use a conventional 3-speed Torqueflite transmission, but it introduced more moving parts and more complexity to the engine.
- To produce reasonable fuel economy, the Chrysler turbine employed a pair of large ceramic heat sinks that heated the incoming charge air while cooling the exhaust. While it was a breakthrough concept for an automotive turbine, again it added complexity and cost to what started out as a simple, reliable powerplant.
By the time you've added a high-volume muffled exhaust, large filtered intakes, ceramic heat exchangers, big transmission, big brakes, and a moderately large fuel tank (You'll be lucky to get 14mpg out of the rig), you've put back all of the weight, cost, and maintenance you were trying to avoid in the first place. No, driving the wheels by means of a gas turbine still isn't practical.
But there is a ray of hope: there may be a place for a small gas turbine in an electric vehicle like the Volt. Running a tiny turbine at constant speed to drive a high-capacity alternator would pretty well solve all the above problems. While accessories would still be of formidable size, a turbine spool that would fit in a shoebox could turn up an alternator that could furnish some pretty serious kilowatts. These micro-turbines, fueled by natural gas are running small electrical plants for remote oilfield pumps and pipeline pumping stations deep in the boonies with very minimal maintenance and no reliability issues. Most of these units fit in a building about the size of an executive desk, and are pretty quiet, even only ten feet away. A unit that size (most of which is sound-deadening material) can easily power a home with up to 15 kW.
A turbogenerator producing only about a third of that could maintain an electric car's battery once the vehicle has put on sufficient miles to require an electrical boost.
Reliability of a gas turbine is legendary - Solar Gas Turbines used to joke that their products were guaranteed for 100,000 hours, or one start. They were intended never to be shut down - which induces serious thermal stress on the turbine, seeing as it is primarily cooled by its own intake air. They could be shut down by turning off the fuel and "windmilling" the turbine with the starter at about 20% for several hours.
With one of these turbine-electric vehicles in your garage, you could plug your house into your car and get off the grid altogether.
Last edited by Lil4X; 07-28-12 at 01:27 AM.
Thread
Thread Starter
Forum
Replies
Last Post
Hoovey689
Car Chat
10
01-08-13 12:37 PM