What might electric cars mean for brisk driving?

[AnotherClarkey]

How might EV's move on the art of driving? Do people want effectively 'one pedal' cars or to stick with acceleration and braking on separate controls? Or do we just want a knob to select this depending on road, mood or conditions like brake bias?

Will manual gearboxes retain their place like on the prototype Morgan made?

What will instantaneous torque vectoring on two or four wheels mean in the real world?

If you plan a 15 mile journey instead of a 150 mile one in your electric sports car will it automatically make 1000bhp available instead of 200?

etc. etc.

For a long time I have wanted an electric tech-fest sports car which can double up as an efficient commuter, it saddens me that so much effort goes in to making tedious stuff like electric Golfs. Maybe the Nissan Bladeglider will deliver on the promise?

[LordFlathead]

If I had a choice I would certainly like the petrol equivalent of a Sport button that changed the map/power delivery quota.

In an electric vehicle it is simplicity itself and the trade off between range and performance is directly proportional. I also forsee a massive market selling maps like turbo cars have because there are so many variables with power delivery that an IC engine cannot compete with. Even the modern huge V8/V12 forced induction monsters cannot only start to deliver rib crushing torque from around 1500 rpm.. whereas a motor can develop all of it from the first rotation of the shaft

You should be able to try several 'maps' in a matter of minutes, and I can see manufactures building this option in at point of sale. How about downloading a new map from the manufacturer while you drive? That will happen too as even BMW specify the option of Internet when you buy the car.

Exciting times ahead

[peterperkins]

LordFlathead said:

If I had a choice I would certainly like the petrol equivalent of a Sport button that changed the map/power delivery quota.

Funny you should mention that I actually make and supply a couple of those type of devices for the Honda IMA Community, inc the Insight G1 and Civic HCH1 cars. It basically boosts the electric assist to the max the car electronics will allow.

It's also fairly easy to hack the Insight and Civic for even more current (+30% for example) with a few simple resistors. A standard Insight runs at 10kw max electric assist and only for short periods, a few simple mods and if you have a good battery you can be looking at 15kw+ for as long as your battery can stand it. I've had 20kw out of mine That makes for very lively performance.

Here's a rolling road chart for my modified G1 Insight Manual car running at about 18kw IIRC.
The torque all comes in at very low rpm exactly as you wish.

http://www.solarvan.co.uk/mdm/RollingRoad2402111.j...
http://www.solarvan.co.uk/mdm/RollingRoad2402112.j...

http://www.youtube.com/watch?v=VQoCgH9gP4k
Ima Boost (Kers Button)

http://www.youtube.com/watch?v=McLUjmOBHYI
Current Hack

Similar mods for other cars will likely be discovered so your wish may be granted.

I expect EV's will build up a techy following like the Insight has, and research by owners shared on forums is the way forward for EV hacking.

Edited by peterperkins on Saturday 14th December 06:45

Edited by peterperkins on Saturday 14th December 06:49

[anonymous-user]

I can see the point of having a knob or button that sets how much regen is targeted at zero throttle, because that is quite driver style / route dependent. (ie on the motorway, having a bit of "sailing" is good, but the same lack of decel would feel dangerous on a B road for example)

But having different "maps" for the actual positive torque proportion of the pedal, nah, not really. If i want more torque, i will simply push the accelerator pedal a bit further to the floor, and if it gets all the way down, then i want full torque. The ability to make 25% pedal actually 50% pedal is just a distraction tbh. Of course, i want the actual pedal mapping to be done well, as it is generally for most modern cars, but i don't really want to be able to change it thanks.

[amstrange1]

Max_Torque said:

I can see the point of having a knob or button that sets how much regen is targeted at zero throttle, because that is quite driver style / route dependent. (ie on the motorway, having a bit of "sailing" is good, but the same lack of decel would feel dangerous on a B road for example)

But having different "maps" for the actual positive torque proportion of the pedal, nah, not really. If i want more torque, i will simply push the accelerator pedal a bit further to the floor, and if it gets all the way down, then i want full torque. The ability to make 25% pedal actually 50% pedal is just a distraction tbh. Of course, i want the actual pedal mapping to be done well, as it is generally for most modern cars, but i don't really want to be able to change it thanks.

This ^^^.

However, for some people I can see the advantage of Eco/Normal/Sport modes with varying pedal maps for both traction and regen torque. Personally though, if I want to drive economically, I'll just avoid 100% throttle - rather than flicking a switch to prevent me ever getting full power. Likewise, unduly aggressive pedal maps for Sport modes are equally irksome.

I'm a fan of one pedal driving in low speed/congested environments as it makes for very easy driving, but does need reasonably aggressive regen to achieve. Easy enough to give a car higher regen power at low road speeds and ramp it off at higher speeds though, so a twiddly knob for regen probably isn't needed - though could make a nice marketing feature.

[conkerman]

Shirly the ECU can do this in the background by monitoring road speed, braking and steering input? No need for a button, you'll just spill your weetabix.

[anonymous-user]

conkerman said:

Shirly the ECU can do this in the background by monitoring road speed, braking and steering input? No need for a button, you'll just spill your weetabix.

It can, but we don't yet have a robust way of sensing driver "mood" (see below). There are times for example, when i just want to sit on the motorway at 65mph, cruise along, and am happy to let my car get max economy, through say using a "sailing mode" or whatever. Other times i'm in a rush, or whatever, and i want to drive more aggressively, when sailing would no be so welcome. Having a basic driver operated "mode" control could make this sort of change easy to implement and obvious to the driver.

I'm completely against having everything "configurable" by the driver though for two reasons:

1) most people will not be able to understand what they are actually changing
2) most people, not being experts, will end up having very non optimum settings for a lot of the time


NOTE: current cars do have adaptive logic to work out how the car is being operated, but this logic, which uses factors such as how fast you apply the accelerator, or how much lateral g you are pulling is a massive compromise between response and stability.
For example, kick down on a modern multispeed autobox. If you trundle along slowly for 20 miles, the system will adapt and enter a "lazy response" mode, to make things as smooth/economic as possible. But then you want to just kick down and overtake a single dawdling car, and urgh, the gearbox takes about 5sec to kick down. That sort of thing feels terrible to me! Generally, drivers like repeatable and linear responses. i.e. the car does the same thing everytime.

[AnotherClarkey]

Max_Torque said:

It can, but we don't yet have a robust way of sensing driver "mood" (see below). There are times for example, when i just want to sit on the motorway at 65mph, cruise along, and am happy to let my car get max economy, through say using a "sailing mode" or whatever. Other times i'm in a rush, or whatever, and i want to drive more aggressively, when sailing would no be so welcome. Having a basic driver operated "mode" control could make this sort of change easy to implement and obvious to the driver.

I'm completely against having everything "configurable" by the driver though for two reasons:

1) most people will not be able to understand what they are actually changing
2) most people, not being experts, will end up having very non optimum settings for a lot of the time


NOTE: current cars do have adaptive logic to work out how the car is being operated, but this logic, which uses factors such as how fast you apply the accelerator, or how much lateral g you are pulling is a massive compromise between response and stability.
For example, kick down on a modern multispeed autobox. If you trundle along slowly for 20 miles, the system will adapt and enter a "lazy response" mode, to make things as smooth/economic as possible. But then you want to just kick down and overtake a single dawdling car, and urgh, the gearbox takes about 5sec to kick down. That sort of thing feels terrible to me! Generally, drivers like repeatable and linear responses. i.e. the car does the same thing everytime.

Years ago my Dad had a Mitsubishi Colt with a 'fuzzy logic' adaptable auto box. Although quite pleaant most of the time it was useless for brisk but responsible driving.

It did change the transmission characteristics quite significantly but was very slow in determining what was going on. It would therefore be relaxed and unresponsive during the thrash, wake up to what was happening just as you hit a 30 limit, hold about 5000rpm in 2nd all the way through some sleepy hamlet then revert to 'mogadon mode' just as you reached the derestriction sign and wanted to thrash some more.

[AnotherClarkey]

Some bold statements coming out of this article:

http://www.autocar.co.uk/car-news/new-cars/nissan-...

I have to admit to being a bit of a fan of the whole Bowlby deltawing-type concept and to having a sneaky suspicion that electric power might open up a whole new chapter in fast driving on the road so I am probably a bit biased but this looks very promising to me....

What do others think?

[LordFlathead]

I think it's great. I saw the original Deltawing at PH Sunday Service at Nissans HQ and was blown away by the aggressive design. If they can get it to market at sub £30k then a lot of people will buy it on looks alone IMO. This is the design of the future and the brand is big enough to pull it off.

By comparison, the i3 looks like a tissue box on wheels

[TransverseTight]

The key thing with electric for brisk driving is efficiency. You can have 400kw (500bhp?) on tap, but thats not derived from a 4litre supercharged V8 which sucks a lot of air and therfore needs a lot of fuel to avoid detonation. Therefore if you are only on part throttle with your EV you only sap a load of 20kw from the battery. Same as a Smart. However if you absolutely must make the next green light, you can hit the pedal to the floor and get the full 400kw and then hits the brakes and get half back through regen.

I think we'll shortly see supercapacitor buffers, with maybe only 1 or 2kWh storage becuse of their high cost, but the advantage is the abilty to suck up nearly 100% of the regen from braking due to their high charge/discharge rates. Combined with main battery storage they offer either a KERS style boost, or offload into the main battery, depending on whether you are in ECO or sport mode.

We'll also see aftermarket mods for rewinding the motor to change peak torque figures to a different point in the rev range, maybe even gearboxes added to stop the back EMF generated at higher revs. Likewise battery upgrades as newer tech comes online.

This is going to require a new generation of motor engineers and tuners. Put it this way, if I were about to go to college or uni, Id be studying electrical engineering rather than motor vehicle studies.

re the nissan. yes please but on a lease, hard car to understand how it works, but the info is on the net. One for auto nerds only I believe which may hit resale values. I wear a lot of weird shoes, and hats, and am a geek, so it will suit me fine

Edited by TransverseTight on Friday 20th December 00:22

[anonymous-user]

TransverseTight said:

I think we'll shortly see supercapacitor buffers, with maybe only 1 or 2kWh storage becuse of their high cost, but the advantage is the abilty to suck up nearly 100% of the regen from braking due to their high charge/discharge rates. Combined with main battery storage they offer either a KERS style boost, or offload into the main battery, depending on whether you are in ECO or sport mode.

I have to disagree on this one. Maybe in racing applications, but for road cars, no way, far too expensive. (Also, complex, because unlike a typical LiPo battery, a capacitors energy is almost directly proportional to the voltage across it. This means you need complex and costly (at high powers) DC-DC convertors to buffer the SCs to the main battery and traction PEs.

Same with flywheels, where the cost and complexity of the system massively limits its practical applications.

Generally speaking, the main limitation to regen power is the Emachine rating and primary Power Silicon ratings. No OEM is going to fit a say 100kW EV with a 500kW traction system just to allow a bit more regen under heavier braking. (especially, as for ultimate economy you need to not brake at all. i.e. all battery energy must go into the roadload only)

TransverseTight said:

We'll also see aftermarket mods for rewinding the motor to change peak torque figures to a different point in the rev range, maybe even gearboxes added to stop the back EMF generated at higher revs. Likewise battery upgrades as newer tech comes online.

Rewinding a traction motor, whilst possible, is extremely difficult. This is because the motor architecture (stator/rotor geometery) is so well optimised for the winding scheme chosen. There is sometimes a small (<10%) improvement to I2R losses from a custom handwind that can maximise the copper fill compared to a machine wound stator, but these days, even the machine wound stuff is getting pretty dam good. Also, a lot of Emachines are using techniques like "bar windings" (i.e the GM Volt etc) that are using solid strand conductors to get very high copper fill. Because of the low integer number of windings per tooth, any change makes a massive difference to your kV! (i.e with a single winding for say 10rpm/volt, add one more wind, for a total of two, and your kV drops to 5rpm/volt)
With power being directly proportional to peak system voltage, the best way to get more power will be to boost system voltages to the absolute max. In this area, the OEM approach is conservative for various complicated reasons (like availability of off-the-shelf power silicon in only two main voltage flavours, concern over motor winding life, and inductive voltage spikes in the PE etc)

Added to which, most modern motors run absolutely on the edge of both saturation and demag effects in order to minimise the active volume (and hence cost) of the Emachine. Average peak power is also completely cooling limited for a traction motor, so although it is certainly possible to get a higher performance from an existing design, you won't be able to get that for too long.

Multispeed gearboxes are going to make an appearance however at some point, to get the maximum tractive effort across the widest road speed range.

Power Silicon upgrades could be possible, but the trend if for custom integrated devices in the Power Electronics (PE) to minimise cost and volume, which will make substitution difficult.

The battery system is ripe for the most easily upgrade, both in terms of energy storage, power capability, and resistive losses.

[McWigglebum4th]

In other words most OEM motors if you push them much harder then designed all the smoke comes out.


And we know electricty works by smoke as when the smoke comes out it stops working therefore smoke must make electricty work

[anonymous-user]

McWigglebum4th said:

In other words most OEM motors if you push them much harder then designed all the smoke comes out.


And we know electricty works by smoke as when the smoke comes out it stops working therefore smoke must make electricty work

At the DC voltages most current EV's work at, it's the lightning coming out you need to watch out for............



(AC HV is a lot safer, because when the AC voltage drops close to zero (as it must do every cycle) the arc "goes out". With HV DC, it just sits there looking like this:



Which is bad if one half of the circuit is made up of you!)

[AnotherClarkey]

So far we have talked mainly about power but are there any opinions about how handling may be affected? Will instantaneous torque vectoring on two or more wheels really change the way we approach road driving or will it be a subtle affair?

Will slow in, fast out still be as relevant or will it be best to pitch in as fast as you dare, keep your foot in and aim for the exit?

[RumpleFugly]

And add in the effect of a lower COG, I can't see why an electric car won't be just as fun to drive.