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BMW unveils third i concept model: i8 Concept Spyder plug-in hybrid

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BMW i8 Concept Spyder. Click to enlarge.

Following on the presentation of the BMW i3 Concept and BMW i8 Concept coupé at the Frankfurt show in 2011 (earlier post), the BMW Group has introduced a third i Model: the BMW i8 Concept Spyder. Like the i8 coupé concept, the BMW i8 Concept Spyder with eDrive is a plug-in hybrid. The 96 kW (131 hp) electric motor on the front axle works in tandem with a TwinPower Turbo three-cylinder gasoline engine sending 164 kW (223 hp) through the rear wheels.

Both power units are in-house BMW Group developments and generate an aggregate system output of 260 kW (354 hp) and peak torque of 550 N·m (406 lb-ft). The BMW i8 Concept Spyder accelerates from 0 to 100 km/h (62 mph) in five seconds on the way to an electronically governed top speed of 250 km/h (155 mph). The two-seater burns three liters of gasoline per 100 kilometres (equivalent to fuel economy of 78.4 mpg US) in the European test cycle.

The electric motor sources its energy from a lithium-ion battery pack which can be fully charged from a domestic power socket in less than two hours. The high-output battery is located in the energy tunnel between the front and rear axle modules; the space-saving and well-balanced packaging of this and other drive and chassis components gives the sporting two-seater ideal 50:50 weight distribution.

With its battery fully charged, the BMW i8 Concept Spyder can cover up to 30 kilometers (19 miles) on electric power alone. If required, a high-voltage alternator hooked up to the combustion engine generates extra power, which is then stored in the hybrid battery. This range-extending function during the course of a journey allows the two-seater to travel further between charging stations.

The BMW i8 Concept Spyder can send power through the front, rear or all four wheels at the same time. Intelligent control electronics ensure that the optimum drive configuration is available for the situation at hand. The driver can view the driving mode currently engaged and monitor the activity of the two drive sources on the large information display in the cockpit. Furthermore, the electronic systems ensure maximum energy recuperation under braking or when coasting.

Compared with the original coupé variant of the BMW i8 Concept, the BMW i8 Concept Spyder has a slightly shorter wheelbase and overall length. Like the coupé, the BMW i8 Concept Spyder is built around the LifeDrive architecture (earlier post), a fusion of independent functional units. For example, the carbon-fiber-reinforced plastic (CFRP) Life module gives the car an extremely lightweight passenger cell, while the Drive modules—made primarily from aluminium components—bring together all the car’s operational driving functions, such as the powertrain, chassis and safety structure.

Lightweight design, encompassing the use of innovative materials, has allowed the unavoidable additional weight of the high-output hybrid drivetrain to be cancelled out in full. The LifeDrive architecture also has been adapted to the sports car character of the BMW i8 Concept Spyder. The front and rear axle modules are connected by an “energy tunnel”, which houses the battery pack. This allows the engineers to give the car a low center of gravity and ideal balance. The distinctive two-way split of the LifeDrive concept is also reflected in the car’s design, which renders the basic elements of the body clearly distinguishable. Expressive surfaces and precise lines create a harmonious transition from one module into another. This overlap and interlocking of surfaces and lines—“layering” in BMW i speak—is displayed both on the body and in the interior of the new car.

Connectivity. BMW i drivers will have a new generation of driver assistance systems at their disposal to enhance both safety and comfort, such as the camera-based proactive Collision Warning system, Parking Assistant and Traffic Jam Assistant.

In addition, BMW i is developing an array of connectivity functions which provide a seamless link between its models and their owners’ lives outside the car. Remote functions accessed via a smartphone help users to locate their car in large car parks (CarFinder); show nearby charging stations; allow the battery to be charged at pre-set times; and inform drivers on the current status of their vehicle. Further, the battery and interior can be brought up to peak operating temperature before the driver sets off on a journey.

The Last Mile Navigation function assists drivers after they have parked their car, with route instructions transferred directly onto their smartphone directing them along the last leg of their journey on foot. The Intermodal Route Planning function effectively integrates the car into the local public transport network and provides information on current parking availability at the driver’s destination.

The central information display in the BMW i8 Concept Spyder allows the driver to view the current status of the hybrid system; provides a platform for menu navigation and route guidance; and uses innovative connectivity functions. The car’s power electronics are linked up to intelligent navigation and traffic guidance systems to enable the hybrid drive system to work at maximum efficiency. In this way, information on route profile, speed limits and unavoidable traffic congestion are incorporated into the calculations of the energy management system so that the hybrid system’s operating strategy can be adapted accordingly.

Intelligent connectivity functions open the door to a host of other practical solutions when it comes to preparing the BMW i8 Concept Spyder for its daily workload. One example of this is automatic calendar synchronization with the driver’s smartphone. The system registers upcoming appointments and, when plugged into a power socket, ensures that the battery is topped up overnight so that the car is ready for action with a fully charged battery the following morning.

Comments

NunyaDam Bidness

19 miles on battery, then it says travel further between charging stations? If you are within that range you should be walking or using public transportation. It's going to be using the ICE most of the time to recharge the battery.

Davemart

Sounds good. What sort of wimp does not walk if it is only 19 miles?
It's even better exercise when you are shopping.

Engineer-Poet

Yeah, what's 6 hours out of your day to walk 19 miles when you could drive it in 1 hour even in traffic?

What's waiting for 2 transfers to make a trip with no direct bus or train?

It's the kind of stupidity that people drive personal cars to avoid, that's what.

sd

0-100km/h in less than 5 sec. 78.4 mpg or maybe an EPA rating of about 62 mpg which is still better than some wimp Prius. What is not to like other than the price? Still the total performance is encouraging.

Nick Lyons

Interesting exercise, but I don't see this as the basis for a practical car. Why have a generator attached to the ICE, which also drives the rear wheels? Why not use the front motors as generators in the through-the-road fashion if you want to recharge the battery while driving? In any event, why charge the battery with the ICE at all? Either reserve your battery for when you need it (city center) or just use up the battery first and supplement with ICE until you are next parked at a charging station. This drive train is too complicated and undoubtedly too expensive for the mass market, IMHO.

Nick Lyons

Interesting exercise, but I don't see this as the basis for a practical car. Why have a generator attached to the ICE, which also drives the rear wheels? Why not use the front motors as generators in the through-the-road fashion if you want to recharge the battery while driving? In any event, why charge the battery with the ICE at all? Either reserve your battery for when you need it (city center) or just use up the battery first and supplement with ICE until you are next parked at a charging station. This drive train is too complicated and undoubtedly too expensive for the mass market, IMHO.

Nick Lyons

Meta: comment system seems to be on the fritz. My last comment posted 2x (only pressed 'Post' 1x). Yesterday, I posted a comment on an earlier thread but it didn't show up at all.

Engineer-Poet

It's a performance coupe, Nick.  The multi-motors are for balancing power between the axles in ways not possible with a through-the-road system.

kelly

There's an interesting article: http://www.theatlantic.com/business/archive/2012/03/why-dont-young-americans-buy-cars/255001/

Perhaps concept cars should be smaller, <$7,000, with 50 maintenance-free EV 'quick charge' urban miles range for affordable transportation appliances or US road-able Nanos.

Roger Pham

@Nick Lyons,
This is a 4WD sport car in the form of a PHEV. As such, in the all-electric mode, there will need to be one motor on each axle, so at least, 2 motors will be needed. I don't see mentioning of any geared transmission at all, so there probably isn't any. This should simplify thing a lot. Now, if one puts a 223 hp engine in the rear, it might as well drive the gear axle through a clutch in order to add this much power to the front electric motor for a total of 354 hp! Now then, if you already have a motor on the rear axle, you might as well arrange so that the motor is connected to the engine and acting as a generator, so that you can recharge the nearly-depleted battery at the engine's most efficient point in the map even when the car is inching along in congested freeway. In this fashion, the two motor-generators with the large battery pack are acting as an automatic transmission system for the engine, allowing efficient power transmission of the engine to the wheels without any variable-gear mechanical transmission.

I see that this arrangement is actually simple, light-weight and cost-effective for all the functions that it is designed to do.

Nick Lyons

@Roger:

This is a 4WD sport car in the form of a PHEV. As such, in the all-electric mode, there will need to be one motor on each axle, so at least, 2 motors will be needed. I don't see mentioning of any geared transmission at all, so there probably isn't any.

Wrong. There is only one motor, and it drives the front wheels. For 4WD, the combustion engine, mounted over the rear axle, runs through a conventional transmission. I stand by my earlier critique. This may be an interesting concept, but it is not simple, and the drive train paradigm is far from cheap or space efficient.

see: http://www.bmw-i.com/en_ww/bmw-i8/

Roger Pham

@Nick,
Indeed, adding another conventional transmission would increase complexity significantly, when one already have a big battery and a big motor that can provide a lots of torque at low speeds. Not only that, but a transmission that can handle 223 hp would make it pretty hefty. I think that for an all-electric range of 19 miles, the battery pack should be able to handle 130 kW of power, so adding another 30 kW motor at the rear axle while reducing the engine to a 2-cylinder-70 kW machine would reduce weight and cost quite a bit while increase luggage space and would not sacrifice acceleration that much. At highway speed, the engine should be able to produce its maximum torque, so combining 130 kW motor power to what ever kW the engine can produce at highway speed would still provide a pretty potent machine.
But of course, this sport car is not about practicality or low-cost, but all about performance, so every second reduction in 0-62 mph time must be obtained.
On the bright side, this sport car boast a very high level of efficiency, way above any other comparable 350-hp 4WD sport car every created.

Peter_XX

@Davemart
It would take me little more than 2 hours to run 19 miles. However, on a bicycle I could do it in 1 hour and be less exhausted when I arrive. If public transportation is available - as it is in many European countries - I might prefer that option now and then but I realize that you have a point when the trips are significantly shorter than 19 miles. If people left their cars at home for shorter trips, the problems with obesity would diminish as an additional benefit.

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