Morgan showcases electric sports car with five speed manual transmission at Geneva
11 March 2012
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| The Morgan Plus E electric sports car features a five-speed manual gearbox and was designed by Morgan with the support of British technology specialists Zytek and Radshape. Click to enlarge. |
Morgan Motor Company showcased an electric sports car with a five-speed manual gearbox at the Geneva Motor Show. Designed by Morgan with the support of British technology specialists Zytek and Radshape, Morgan showed it as a concept to test market reaction, suggesting that it could enter production if there is sufficient demand.
The Plus E is based on a tailored version of Morgan’s lightweight aluminium platform chassis clothed in the revised traditional body from the new BMW V8-powered Plus 8, also launched at Geneva. Power is delivered by a new derivative of Zytek’s 70 kW (94 bhp), 300 N·m electric motor, which is already proven with US vehicle manufacturers.
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| The Morgan Plus E concept will be powered by a derivative of Zytek’s production 70kW E-Drive, providing 300 N·m of torque. Click to enlarge. |
Mounted in the transmission tunnel, the Zytek unit drives the rear wheels through a conventional five-speed manual gearbox. The clutch is retained, but because the motor provides torque from zero speed the driver can choose to leave it engaged when coming to rest and pulling away, driving the car like a conventional automatic.
A multi-speed transmission allows the motor to spend more time operating in its sweet spot, where it uses energy more efficiently, particularly at high road speeds. It also allows us to provide lower gearing for rapid acceleration and will make the car more engaging for keen drivers.
—Zytek Automotive managing director Neil Heslington
The program will deliver two engineering concept vehicles. The first, with the five-speed manual box and Li-ion batteries, will be used for preliminary engineering assessment while the second will be closer to potential production specification, with alternative battery technologies and possibly a sequential gearbox.
The collaborative research and development project is part-funded by a £100,000 (US$157,000) grant from the UK Government’s Niche Vehicle Network Programme, which is managed by CENEX to promote the development and commercialization of new low-carbon vehicle technologies.
Zytek’s sales and marketing director Steve Tremble said that one of the reasons for joining the consortium is to show the ease with which his company’s technology can be integrated with a rear-wheel drive platform.
Zytek’s first experience with a high-performance electric sports car was in 1997 when it converted a Lotus Elise to electric drive. The award-winning design led to engineering programs with Chrysler and General Motors, closely followed by a long-term relationship with Daimler to develop and build electric powertrains for the smart fortwo ed (electric drive). In motorsport, Zytek was the first company to race a hybrid at Le Mans and supplied technology for the first KERS-equipped Formula 1 car to win a grand prix.
The Niche Vehicle R&D Programme provides support and grant funding for groups of companies throughout the UK that are active in the niche vehicle sector. The programme is funded by Advantage West Midlands and the Technology Strategy Board. Managed by CENEX, it promotes the development and application of new technology to take advantage of the increasing market opportunities for lower carbon vehicles.
Radshape, one of the UK’s leading specialist manufactures of high-precision sheet metal components and assemblies, built the modified chassis.
That looks like a lot of fun. I hope it goes into production.
Posted by: Engineer-Poet | 11 March 2012 at 09:09 AM
Cool. This is perfect for Morgan, a second car you drive for fun on weekends, mostly. With lots of low end torque, it should be quite fun to drive, assuming it isn't too heavy.
Posted by: Nick Lyons | 11 March 2012 at 10:26 AM
You're right E-P, this should be a fun car to drive. I've found you don't need an over powered, really fast car to feel like you do, if the car is low to the ground. I've actually driven my grandfather's three wheel morgan and that was a blast! I've also gone street luging and I can tell you then you're only 2in off the ground even a slow 50mph feels like a hundred and fifty.
Posted by: ai_vin | 11 March 2012 at 12:12 PM
Great! Manual gear transmission is cheaper than copper and permanent magnets. There is no better way to keep the motor cool and efficient by spinning it fast at optimal loads during acceleration, rather having to lug it down in an EV without a multi-gear transmission. Gearshift in an EV is optional, depending on how fast you wanna accelerate the car. If you don't mind a gradual acceleration, there is no need to shift the gears at all. Just leave it in the highest gear all the time, except when climbing steep hills.
Having a small motor that spins real fast can deliver the same power but at less cost and lighter weight than a big motor that turns slowly, provided that you can provide the high voltage and cooling required to protect the motor. Toyota practiced this principle in their Prius III and Lexus hybrid drive trains.
Posted by: Roger Pham | 12 March 2012 at 12:49 AM
A multi-speed transmission allows the motor to spend more time operating in its sweet spot, where it uses energy more efficiently, particularly at high road speeds. It also allows us to provide lower gearing for rapid acceleration and will make the car more engaging for keen drivers.
—Zytek Automotive managing director Neil Heslington
Excuse me "sweet spot" !! and they've been at this since 1997.
Look I appreciate that they want to place the motor system operating point at its most efficient - as if spirited motoring actually has one - but at the same time they do the transmisssion tunnel mounting thing.
So it's OK to turn the power through 90 deg for the rear axle drive incurring an approx 30% torque loss there, as long as the motor itself is efficient ?
If my memory is correct this was specifically avoided by the designers of the Tesla roadster and you won't find the EV1 and Nissan Leaf doing it either.
Of course anyone who uses an electric motor with a multi ratio gearbox is suspect to me. Even Tesla saw the light and eventually abandonned that one. Difficult to control gear changes with high revving motors without impinging severe wear to the clutch.
What they really mean is that they probably have to limit motor speed to 6000 rpm for that reason.
With an induction motor drive you can extend constant power at least 2:1 above base speed so it is no use changing gear above that region.
What is less well known is that constant power can be extended below base speed by overcurrent. Most copper rotored machines will allow 3.0 to 3.5 times nominal torque before breakdown.
Posted by: T2 | 12 March 2012 at 10:39 AM
@T2,
Agree with you that a 5-speed transmission for an EV is way overkill. It's kinda like chewing gum and cracking your knuckle...just for the heck (fun) of doing it! A two-speed transmission would be sufficient to optimize power and efficiency.
However, I have a hard time understanding how a tunnel-mount transmission driving a rear axle would lead to a 30% torque loss? Please kindly educate us on that.
Also, how would an E-motor causes more severe clutch wear in comparison to an ICE?
First of all, an E-motor-transmission would not need dry clutch ("the clutch" as you stated) in the first place, since the E-motor does not need to idle while the vehicle is standing still. Second, in a synchromesh transmission, gear change does not need to de-clutch the dry clutch for each gear change after the vehicle is moving.
Third, an E-motor has much lower rotational inertia in comparison to its torque output, than a comparable ICE. May be as much as 1/4-1/10th or even less, than that of a comparable piston engine, the latter having counter weights on a massive crankshaft and a flywheel and clutch plates and accessories such as generator and water pump etc. An E-motor has to turn above 20,000 rpm in order to have similar rotational energy as a comparable piston engine running at 6,000 rpm. This means that motor speed change can be effected much more rapidly and precisely than in a piston engine, and due to the lower rotational enertia (mass), clutch wear on the synchronizing clutches would be much reduced, and the dry clutch ("the clutch") would not be needed. In fact you wouldn't want a dry clutch, because you need to connect the motor to the drive train even during deceleration for regenerative braking.
Over-current an electric motor will lead to severe lost of efficiency and shortening of motor life. It's far better to speed it up with a lower gear when you need a lot more low-rpm torque.
Posted by: Roger Pham | 12 March 2012 at 04:37 PM
If you were clever, you could put sensors on the shift gates and have the e-motor spin itself to match the speeds of the gears about to engage. Clutchless shifts all the time.
Posted by: Engineer-Poet | 12 March 2012 at 07:56 PM
That is part of quoting electric motor efficiency, most quote the peak efficiency number and not the average.
Even with a 3 to 1 final differential, the electric motor takes lots of current accelerating from a stop, the faster you accelerate the more current it takes and a less efficient motor average.
Posted by: SJC | 13 March 2012 at 08:21 AM
Clutchless electronic gear shifting:
http://www.wrightspeed.com/circuit.html
I wonder how this Morgan selects Reverse, probably mechanically reversing.
The reason for 5-speed is probably because nobody makes 4-speed manuals for many years.
E-P:
Nissan 370Z manual has defeatable, optional feature, called SynchroRev. It matches rpms, intended for downshifting. I think Nissan put gear sensors inside the transmission, not near the shifter.
Roger:
For 2-speed transmission for an electric motor, would you rather use a sliding gear 2-speed AMT, or 2-speed planetary transmission, as you were suggesting earlier (I think)?
T2:
"So it's OK to turn the power through 90 deg for the rear axle drive incurring an approx 30% torque loss there,..."
You probably refer to loss in hypoid gears.
Nissan GTR (AWD) power flow goes front to rear, then back to front wheels. Expert estimate the total power loss from engine to wheels is about 15%. It uses DCT transmission.
I found that induction motors can be very inefficient at low rpm, high torque, mode, as low as 30-40%. It would be beneficial to reduce time spent in that area, by multi-speed transmission. Also performance would be improved.
Apparently those axial flux motors (like ECO Electric, Yassa Oxford) have reduced rpm range, they would need a multi-speed transmission.
Posted by: MG | 13 March 2012 at 11:01 AM
It comes back to weight and roll resistance. The Tesla is induction, but they are counting on the average motor efficiency for their range.
The EVO axial motor is interesting. They get good power in a small package and have been doing some interesting demonstrations lately. The Infinity concept car uses EVO and Lotus for an EREV configuration, smart moves.
Posted by: SJC | 14 March 2012 at 09:22 AM
@MG,
In passenger EV's with good power-to-weight ratio, a two-gear transmission is sufficient. An electric truck with lower power-to-weight ratio may require more gears. A planetary unit is more advantageous in that it is more durable and has less friction loss in the high gear. In the low gear, the gear friction loss may be slightly higher than in the sliding gear transmission, but the car will cruise for most of the time in high gear.
Posted by: Roger Pham | 14 March 2012 at 01:05 PM