Thursday 25th February 2010

Tech Details: Hybrid Lotus Evora

Lotus Evora range-extender hybrid gets 408bhp, 590lb ft, 300-mile range

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Lotus has bagged the prize for the least revealing unveil in the run-up to the Geneva show with this image of its show star, the Lotus Evora 414E Hybrid concept.

Fortunately, Lotus is a little more forthcoming on the details of the Evora 414E Hybrid. The concept, which lotus describes as a 'high performance technology demonstrator', provides 408bhp (or 414ps, hence the name) and 590lb ft of torque via a combination of twin electric motors and Lotus's clever 1.2-litre three-cylinder Range Extender internal combustion engine.

The two electric motors power each rear wheel separately, but via a single-speed geartrain integrated into a common transmission housing. The juice for the motors are stored in a lithium polymer battery pack mounted amidships. The internal combustion engine provides no direct motive power, but its 47bhp at 3500rpm converts mechanical energy to electrical energy via the integrated electrical generator to replenish the battery pack charge and provides additional vehicle range.

Thanks to an innovative 'monoblock' design that integrates the cylinder block, cylinder head and exhaust manifold in one casting, the three-cylinder internal combustion motor is small and light (the whole shebang weighs in at just 85kg), and will work on either alcohol-based biofuels or conventional petrol. In combination, the electric motors can get the concept to 60mph in less than four seconds, while the range extender can get the Evora 300 miles before a recharge is required.

For those wishing for a little combustion-style aural excitement, the Evora 414E Hybrid is fitted with what Lotus calls HALOsonic sound technology. As we revealed when we first wrote about the Lotus artificial engine noise system, the fake engine noises have been developed in conjunction with Harman International, and consist of synthetic engine noises both inside the cabin and outside, via speakers mounted at the front and rear of the car.

On the Evora 414E hybrid, there is a range of four 'engines' to choose from, including V6 and V12 options.

But if that sounds weird get this: despite having a single-speed drivetrain, the Evora hybrid concept has a virtual gearbox that simulates seven distinct ratios. The driver can operate these via steering column-mounted paddles. The torque is even modulated when you shift to simulate a gearshift jolt. Apart from feeding the denial of drivers, the system does have a significant real advantage - it can help stabilise the car under deceleration by simulating engine braking.

A serious contender for a 'Weirdest Lotus Ever' award, the Evora 414E will be unveiled in the metal at the Geneva show at the beginning of March.

[appletonn]

Love this!

Lotus appear to have their finger on the pulse of the average petrolhead, when it comes making electric cars more desirable.

I'll have the Aston V12 Vantage soundtrack please on mine!

[kambites]

I assume you can turn off fake gearbox to give you full power all the time? Hopefully you can turn off the daft engine noises too.

[Bill Carr]

That's really clever and quite a cool application of technology.

[Jackass]

Just select top gear and plant it surely.

I'm sure its more to do with giving the driver control over engine braking than anything else.

[kambites]

Jackass said:

Just select top gear and plant it surely.

I don't know, that might cut torque right back at low speed to "simulate" the lack of torque of an internal combustion engine. Depends on how it's implemented I guess.

[l-plate]

liking that photo and the PCB styling on rear window...looks a little 'alien'.

[appletonn]

Jackass said:

Just select top gear and plant it surely.

I'm sure its more to do with giving the driver control over engine braking than anything else.

Absolutely and I suppose in turn, making it closer to the 'normal' car driving experience and thus more appealing.

I for one, would certainly miss the sound of a creamy V6 or throbbing (missus!) V8 in a single gear milkfloat.

[Mr Gear]

Maybe they can add some synthetic exhaust stink or a simulated blown head-gasket too?

Joking aside, it was only a matter of time when Lotus or someone else did this. I'm looking forward to seeing the whole thing.

[patmahe]

Love the homage to these guys on the engine cover

[dvs_dave]

Now this is more like it! A hybrid with some proper performance credentials! I wonder how long it can exert it's full 400 bhp for? They mention recharge? Does that mean it needs to be plugged in or can the little engine take care of re-charging the batteries independently? I.E., you just slow down for a bit and the excess generator power charges the cells back up or do you leave it parked up for 10 minutes with the generator running and it charges the battieries back up again?

I wonder if it will have an "auto charge mode" whereby the generator can switch itself on and off to always ensure a full charge, even whilst unattended?

The engine noises and gearshift simulation is a bit pants though. Just the next step on from those frankly ridiculous loudspeaker fake wastegates!

[hairyben]

It's all a bit nintendo for my liking. A bit "fake stone cladding".

The actual drivetrain tech looks fine though, in a "if we have to have it" way, at least make it do it's job as well as possible.

Edited by hairyben on Thursday 25th February 12:28

[Gr1fff]

Yer the gears are purley simulation. All electric motors have a form of engine braking normally one state of engine braking. With the evora setup it gives you seven states basicly.

One thing i cant really get my head around is that the range extender is charging the batteries which give power to the motors. So basicly the little 3 cylinder is putting out 414ps though charging the batteries? Thats a good idea!

[teen_cerbera]

Its a matter of time before "Jamster" or the like start advertising:

"Get your Only Fools & Horses 3 wheel van sound track sent straight to your car"



p.s. Iv always thought that having an internal combustion engine to re-charge batteries while on the move was the way forward.

[Mr Gear]

Gr1fff said:

One thing i cant really get my head around is that the range extender is charging the batteries which give power to the motors. So basicly the little 3 cylinder is putting out 414ps though charging the batteries? Thats a good idea!

Sort of... The range extender internal combustion engine can only put out 47bhp according to the article, but the electric motors can put out 10 times that. Put simply, you don't use full power all the time, and the batteries act as a "power regulator".

When you are using less than 47 horses at the wheel, the battery can re-charge from the genny. When you are using more than that, the batteries are depleting. When the batteries are totally flat, you wouldn't ever have more than 47bhp available at the wheels.

[royceybaby]

Probably already been asked before.

But will the little combustion engine provide a more economical source of power to keep the batteries charged, once the batteries run out, than just having a "standard" Evora engine running for the same 300mile range?

The performance figures looks great and I like the direction that Lotus has taken with their range extender instead of the Prius setup which just screams fake green credentials to me.

Royce

[Mark Wibble]

appletonn said:

I suppose in turn, making it closer to the 'normal' car driving experience and thus more appealing.

+1

It's interesting how the most innovative technology in the world is worth nothing if the public reject it.

E.g. tilting mechanism in the APT- everyone said they felt sick. Whole new market (potentially) for the UK goes up in smoke. What do all high-speed train networks round the world use now? Tilting trains...

Getting the public on-side is crucial, so it could be the thing to bring electric cars to the masses!

Go Lotus! [rotates fore-arms in a horizontal plane]

[Twincam16]

kambites said:

I assume you can turn off fake gearbox to give you full power all the time? Hopefully you can turn off the daft engine noises too.

Or use non-conventional engine sounds.

I quite fancy a Star Trek-style warp-drive-engage sound when flooring the pedal, and maybe a diving Stuka under deceleration.

[Or888t]

Great look into the future, since this is the way "We have to go" Can't stand the fake engine noise idea though.
Anyway.. Looks like lotus have been watching Top Gear, with there range extender idea.

[munch997]

They should use a KERS system to recharge the batteries, so the movement of the wheels turning stores the energy so the batteries recharge whilst driving, then you wouldn't need a petrol motor.... another thing is why use a petrol engine, surley diesel would be more eco as the fuel economy is better?
(aimed at all manufactures not just Lotus)
Would that work?

[dlockhart]

Twincam16 said:

kambites said:

I assume you can turn off fake gearbox to give you full power all the time? Hopefully you can turn off the daft engine noises too.

Or use non-conventional engine sounds.

I quite fancy a Star Trek-style warp-drive-engage sound when flooring the pedal, and maybe a diving Stuka under deceleration.

Will engine noises be the new Ring tones... oh God NOOOO!!!