English company shows V10 hybrid sports car
An entirely new spin on the hybrid automobile has been developed by Connaught Motor Company (UK) – a V10-electric hybrid engined, Type-D sports coupe capable of 140mph, 0-60mph in 6.2s, and a stunning 42mpg while still complying with ultra-low emissions targets set for 2010. Connaught plays down the Type-D's hybrid drive, wishing to distance its sports coupé “from existing hybrid cars with their utilitarian aura and earnest greenness.”
So for 'hybrid', read Connaught's alternative description: HigherBred. They think of the electric motor as a torque-assist system, a means to an end rather than an end in itself.
The high performance energy-efficient sports car is the brainchild of two ex-Jaguar consultant engineers and has no less than17 patents pending on its technology.
The car was previewed at Goodwood's Revival meeting, a fitting venue to resurrect a famous name of 1950s automotive engineering, but the new Connaught Motor Company is no heritage-laden throw-back to past eras.
Connaught is the first virtual car company. It designs the car and manages the project, but out-sources the manufacturing to Derby-based partners EPM Technology, thereby ensuring relatively low start-up investment costs.
The ultra-lightweight construction helps to realise the ambitious fuel efficiency targets while the mid-front north-south mounted engine and rear-wheel drive configuration guarantees maximum driving pleasure without compromising rear space.
The cleverly engineered convertible ‘Eclipse’ version will have electrically-powered stacking glass panels which disappear into the boot lid without loss of luggage space. The Type-D will be “competitively priced” starting at around UK£35,000.
“Our aim has been to build a car for the future while keeping the design and technology relatively simple,” explains Tim Bishop, vehicle engineering director, “and to establish close links with our technology partners EPM Technology for the assembly and Coventry University on the styling side.
“We have met all our own development targets and are confident to gain five-star EuroNCAP crash test results and maximum score for pedestrian safety.”
The directors of Connaught are now seeking further investment to raise the £5 million required to take the project through to production in May 2006.
The all-aluminium, ultra-compact, 2110cc V10 engine is packed with innovative features.
The vee-angle is just 22.5 degrees, which makes the engine narrow and gives good balance with even firing intervals. The wet cylinder liners mate directly with the cylinder head, with no gasket, and other components are sealed with rubber where necessary.
The crankshaft is pressed together from 22 components, and fed into the block from one end. Its webs double as very large main-bearing journals, but the bearing surface is very slender to keep friction down.
The pistons have ceramic crowns, to reduce the heat transfer to the block that would otherwise be the V10 configuration's biggest snag given a cylinder surface-to-volume ratio much higher than that of, say, a four-cylinder engine. Future developments could include V8 and V12 versions of the engine.
For a rapid warm-up and maximum efficiency, the cylinder head has its own water-cooling circuit. When the block needs to be cooled as well, an interconnecting valve opens to unite the cooling circuits, pumped by an electric water pump as required.
There are two valves per cylinder, a single overhead camshaft per bank with bucket tappets and variable valve timing system, and a very high (13.5 to one) compression ratio. Cross-linking of opposite inlet ports produces pressure pulses to improve low-speed torque, and each cylinder has its own throttle valve.
The engine alone reaches its torque peak at 4000rpm, but with the electric motor assisting its efforts there's a flat torque curve of 144lb ft from 1000rpm right up to 6000rpm. That strong low-end pull is the secret of the Connaught's pace, delivering a pulling ability extraordinary for such a compact engine unit. Maximum combined power – 162bhp – arrives at 6000rpm.
The Lynch electric motor is attached to the crankshaft nose, via a variable gearing system designed to exploit the fact that an electric motor delivers its highest torque at its lowest speeds.
The drive system ensures that the motor always runs at the best speed for the conditions. It's powered by, and recharges, a 48-volt electrical supply, which keeps current levels low and makes for quicker recharging.
There's also a capacitive and fast charging storage system to respond instantly to big current demands, for example to help with sudden acceleration.
When the Type-D is stationary, the petrol engine does not run. The air-conditioning can still operate if needed, though, thanks to that 48-volt electrical system. To move off, you press the clutch pedal down, select a gear, press the accelerator and the engine fires up as you engage the clutch and move away.
There's none of the usual chatter and jerk of a conventional starter, because the electric motor performs the job of starting the engine.
Three modes alter how the electric motor is used. Sport mode uses all available motor assistance, but will use up the battery power so it cannot be engaged all the time. Normal mode adds battery charging on deceleration (regenerative braking) and rations the motor assistance.
Economy mode maximises the deceleration charge. Pressing the sport button also opens valves in the intake and exhaust systems for a sportier sound – 'like a Formula One car at half speed,' says Tim Bishop.