So, EV performance cars are coming soon, right?

[832ark]

Gary C said:

NS66 said:

The problem is a standard EV car ie Ioniq 5, Ipace EV6 oven Kona and E Niro have amazing performance - certainly way more than supercars of the 90's.

Humm

E Nero 0-60 7.5s

1990 964 turbo 0-60 4.6s
1999 996 GT3 0-60 4.5s

A quick google suggests an Ioniq 5 225kw will run a 1/4 mile in a similar time to an e36 M3 Evo so maybe not 90’s supercar quick but certainly as quick as one of the 90’s performance benchmarks.

[off_again]

RobDickinson said:

https://unpluggedperformance.com/product/model-s-p...

$10k for ceramics, not bad but I'm guessing it'll eat them quickly.

Track mode should help will increase regen and cooling

I really dont know what manufacturer they are using for the brakes, but a good set of carbon ceramics should last well. Mercedes quote that they expect all carbon ceramic brakes to last 150k km road miles and regular use on track for 20-30km every year. Yeah, you can absolutely burn through a set pretty quickly if you really want to try, but a couple of track days per year and 20k km per year and they should last 5-10 years without replacement.

Now, pads..... thats another matter! And of course, factor in the cost of replacement.

[off_again]

832ark said:

Gary C said:

NS66 said:

The problem is a standard EV car ie Ioniq 5, Ipace EV6 oven Kona and E Niro have amazing performance - certainly way more than supercars of the 90's.

Humm

E Nero 0-60 7.5s

1990 964 turbo 0-60 4.6s
1999 996 GT3 0-60 4.5s

A quick google suggests an Ioniq 5 225kw will run a 1/4 mile in a similar time to an e36 M3 Evo so maybe not 90’s supercar quick but certainly as quick as one of the 90’s performance benchmarks.

I think we need to reset expectations here. If you are looking for a 1/4 mile drag car, fine, EV is probably the way to go now (depending on what class you want to race in). But performance is so much more than 0-60 sprints. How have we ended up here? Why are we focusing on a single metric as the guidance for 'performance'? There is so much more to a performance car, and as history has shown us in the past, many cracking cars to drive weren't the fastest!!!

I remember the days of the Astra GTE, Golf GTI and XR3i - the Astra was the fastest, the XR3i was the cheapest and the GTI the slowest (and most expensive). But the GTI handled really well, drove brilliantly and won lots of tests back in the day. Performance is so much more than 0-60!

Now, a smaller, lightweight, decent range EV sports car with a good dynamics setup and a modern generation electronics package certainly sounds good to me!

[px1980]

NMNeil said:

My belief it will be the same as when they introduced compulsory seat belt use. To begin with drivers were given a warning to allow them to get used to the new law, but this only lasted a while before the seat belt law was being fully enforced.
At the moment the ISA can be turned off, but each time it is a log is made in the ECM, and the insurance company and police can get a copy of this log in the event of a crash.

“It’s important to clarify that the EU legislation proposes that the systems should be overridable, allowing the driver to accelerate beyond the limit if required to do so.”

The legislation also suggests that the systems should also be ‘default on’, manually cancellable and recycle on the ignition cycle, meaning the system resets to the ‘default on’ setting every time the car is restarted.

https://www.thatcham.org/intelligent-speed-assista...

Once the system has been in place for a few years the off switch will probably be removed.

If this happens, won‘t all the performance brands lose their very reason for existence? I can‘t see anyone buying a Porsche/Ferrari/etc or even an M3/RS3 type car if speed is limited to 70mph at all times. Such legislation would literally kill billions of $ worth of car sales.

[SWoll]

px1980 said:

If this happens, won‘t all the performance brands lose their very reason for existence? I can‘t see anyone buying a Porsche/Ferrari/etc or even an M3/RS3 type car if speed is limited to 70mph at all times. Such legislation would literally kill billions of $ worth of car sales.

Is high speed their very reason for existence? Handling, chassis balance, engine note, low speed acceleration, styling etc. not important?

Plenty of great driving roads in the UK where you'll not get much above 70.

[Simond S]

Quite funny people arguing about the sportiness of electric cars.

Bought an i3s a few weeks ago. It has the same addictiveness that the Lotus 111r gave. Superb acceleration, nimble and fun to drive.

In fact, I would suggest anyone who is knocking the fun factor has probably never driven a EV, unless they truly believe that fun only comes from double declutching and the smell of Castrol R.

[NMNeil]

px1980 said:

If this happens, won‘t all the performance brands lose their very reason for existence? I can‘t see anyone buying a Porsche/Ferrari/etc or even an M3/RS3 type car if speed is limited to 70mph at all times. Such legislation would literally kill billions of $ worth of car sales.

Yes, and will that be a bad thing considering the carnage on the roads cause by speeding?

[off_again]

Simond S said:

Quite funny people arguing about the sportiness of electric cars.

Bought an i3s a few weeks ago. It has the same addictiveness that the Lotus 111r gave. Superb acceleration, nimble and fun to drive.

In fact, I would suggest anyone who is knocking the fun factor has probably never driven a EV, unless they truly believe that fun only comes from double declutching and the smell of Castrol R.

i3 owner here also. Mmm, I absolutely would agree with you on a few of those comments. Yes, its a blast and a 'pocket rocket' really sums it up for me. Narrow tires, low CoG and just enough power means it can be fun. But, I would also caution on a few points. Regen braking is actually a lot of fun if you get used to it. It almost is like trail braking when entering a corner, bringing a level of tightening of the turn. There are issues though, and its a great example of how tuning the dynamics around EV's has, and will continue, to improve. Lotus chassis engineering is way better though!

I have seen that the regen braking when you get to the limit will disable or reduce while in a turn. Then you have the stability control that is a fairly good system, but not that well balanced with the regen braking and overall grip (mines a Rex, so has a bigger pendulum effect). Found on a couple of tighter and constant radius turns that it will start to behave weirdly - though to be fair, I am talking 9/10ths here! You can turn off stability control, which does improve things a little, but its still there with the regen braking part. Its very disconcerting to have this work on entry, only to disable and de-stable the chassis, causing the stability control to do things!

I know things improved with the i3S that has wider track and changed suspension that balances the grip and stability control better. And the Rex model does have extra weight at the back, so I have to factor that in too. But its a great example of why I believe that engineers have so much to play with here - chassis balance, grip, regen braking, stability control and torque vectoring. Its complex, but imagine what a manufacturer can do if they can balance all of this? How about a car that can torque vector on turn in, manage the balance and support the transition on exit. How cool would that be? A car that can pivot well, feel balanced and bring a bit of 'fizz', imagine that?

Its like the first time I drove a Boxster. I was a snob. Slow, small engine and the 'cheap' Porsche. Then I drove one....

[Discombobulate]

Simond S said:

Quite funny people arguing about the sportiness of electric cars.

Bought an i3s a few weeks ago. It has the same addictiveness that the Lotus 111r gave. Superb acceleration, nimble and fun to drive.

In fact, I would suggest anyone who is knocking the fun factor has probably never driven a EV, unless they truly believe that fun only comes from double declutching and the smell of Castrol R.

Glad I am not the only one. I thought I had lost the plot. I have a cooking 120 i3 and I love hooning around in it - as does my wife. We have a 911 and RS4 collecting dust at the moment....

[Gary C]

Discombobulate said:

Simond S said:

Quite funny people arguing about the sportiness of electric cars.

Bought an i3s a few weeks ago. It has the same addictiveness that the Lotus 111r gave. Superb acceleration, nimble and fun to drive.

In fact, I would suggest anyone who is knocking the fun factor has probably never driven a EV, unless they truly believe that fun only comes from double declutching and the smell of Castrol R.

Glad I am not the only one. I thought I had lost the plot. I have a cooking 120 i3 and I love hooning around in it - as does my wife. We have a 911 and RS4 collecting dust at the moment....

Its mixing the age old fact that small, nimble, adequate powered cars are often more fun to drive than 'pure sports' cars. Its not just a EV thing.

I thrash my 1.0 Polo far more than I do the 911, and probably have more actual driving fun in it but I would not get rid of the 911.

I am looking forward to getting my first electric 'performance' car (an electric GT86 would be ideal) and really getting down to learning LFB

Will I mourn the loss of the petrol engine, hell yes.

[survivalist]

off_again said:

832ark said:

Gary C said:

NS66 said:

The problem is a standard EV car ie Ioniq 5, Ipace EV6 oven Kona and E Niro have amazing performance - certainly way more than supercars of the 90's.

Humm

E Nero 0-60 7.5s

1990 964 turbo 0-60 4.6s
1999 996 GT3 0-60 4.5s

A quick google suggests an Ioniq 5 225kw will run a 1/4 mile in a similar time to an e36 M3 Evo so maybe not 90’s supercar quick but certainly as quick as one of the 90’s performance benchmarks.

I think we need to reset expectations here. If you are looking for a 1/4 mile drag car, fine, EV is probably the way to go now (depending on what class you want to race in). But performance is so much more than 0-60 sprints. How have we ended up here? Why are we focusing on a single metric as the guidance for 'performance'? There is so much more to a performance car, and as history has shown us in the past, many cracking cars to drive weren't the fastest!!!

I remember the days of the Astra GTE, Golf GTI and XR3i - the Astra was the fastest, the XR3i was the cheapest and the GTI the slowest (and most expensive). But the GTI handled really well, drove brilliantly and won lots of tests back in the day. Performance is so much more than 0-60!

Now, a smaller, lightweight, decent range EV sports car with a good dynamics setup and a modern generation electronics package certainly sounds good to me!

Yon also need to factor in that the reason EVs are good at 0-60, 0-100 and 1/4 mile runs is because they don’t have a gearbox (in terms of being able to select gears).

The downsides are lower top speed - the Ioniq isn’t far off it’s too speed when it hits the 1/4 mile, whereas the M3 was designed for high speed driving (in the 90s it was still possible to make progress on the autobahn).

If the M3 was geared for a 117mph top speed then, even with the pesky gear changes, I’d have likely outperformed the Ioniq on the 1/4 mile.

[SWoll]

survivalist said:

Yon also need to factor in that the reason EVs are good at 0-60, 0-100 and 1/4 mile runs is because they don’t have a gearbox (in terms of being able to select gears).

The downsides are lower top speed - the Ioniq isn’t far off it’s too speed when it hits the 1/4 mile, whereas the M3 was designed for high speed driving (in the 90s it was still possible to make progress on the autobahn).

If the M3 was geared for a 117mph top speed then, even with the pesky gear changes, I’d have likely outperformed the Ioniq on the 1/4 mile.

It's the instant power and torque along with an incredibly linear delivery that makes them so quick. They aren't setup for high speed as of little use in most cases but of course could be.

Look at the Model S Plaid. 0-60 in 2 seconds, 0-100 in 3.5, 1/4 mile in 9 seconds at 155mph and 200 mph top speed, all with a single gear.

Look at the power curve.

[RobDickinson]

Yeah the power dropping at higher speeds is a solved problem now.

It'll roll out to other tesla models eventually and other competing companies will do their own thing, no need for a dual speed gearbox like the taycan

[GT9]

Feeling the need (again) to throw some science into the mix....

I want to talk about gearboxes.

On the recent Chevy 10.4 litre crate engine thread I had a poster telling me I was confusing torque and power, and then promptly claimed that electric motors provide full power from zero speed.

Which is of course impossible as anything multiplied by zero is zero.

I then spent several pages attempting (with limited success) to explain how a relatively lightweight 2WD car fitted with a high torque engine will potentially accelerate more quickly to a decent top speed if you remove the multi-ratio gearbox.

Now before you shout bks, bear with me, and remember that the 0-400-0 kph record is (or maybe was) held by the Koenigsegg Regera.

To understand what is required for acceleration, we should go back to the laws of the universe, and see what they tell us.

Acceleration requires energy to be added to the motion of the car to overcome several things.

In order of typical magnitude, as far as the acceleration event is concerned, these are weight, drag and rolling resistance.

For a constant rate of acceleration (fixed G), the power required to overcome each, as a function of ground speed is:

Weight > linear relationship
Drag > cube law relationship
Rolling resistance > linear relationship

These assume weight, incline, drag coefficient, rolling resistance coefficient and frontal area remain the same throughout.

For all road speeds below say 200 mph the addition of kinetic energy is by far the biggest power consumer.
Once you reach a constant high speed, drag then of course takes over.

As a point of reference, even for a very light 1000 kg car like an Ultima, at 101 mph and 0.77 G acceleration, the power demand at that speed would be:
343 bhp to increase kinetic energy, 31 bhp to overcome drag, and 6 bhp to overcome rolling resistance.

Now here is the bit that I think is not widely understood.

To accelerate a car from standstill at a fixed G requires a fixed value of torque to be applied to the wheels at ALL road speeds.

Not power, but torque.

Admittedly the required torque value will start to rise very slightly as drag becomes more prominent but for the sake of a discussion about a typical car accelerating to 150 mph, it's essentially a fixed value.

What this means is that the power REQUIRED to accelerate a car at a fixed G from standstill rises LINEARLY from ZERO.

You do not need lots of power to accelerate at low road speeds, what you need is torque.

Because an ICE does not produce a fixed torque at all engine speeds, and typically not enough torque, we use a gearbox to try to maintain access to the peak torque, multiplying it, whilst also then applying full engine power at low road speeds.

Which we've just shown isn't necessary.

The gearbox is essentially a fudge to try to mimic a constant torque device, but comes with quite a lot of lost energy along the way due to heat/inertia in the transmission, lost traction, and torque discontinuity at gear changes.

On the other hand, because an electric motor can produce high torque from zero speed, it doesn't need the gearbox.

With an EV you just set the torque at whatever value is required for the target rate of acceleration, connect the motor directly to the wheels (via whatever fixed reduction ratio you want), open the taps, and away you go.

No fuss, just a perfect match to the requirements.

This is why similarly matched EVs always seem to outdrag the ICEs.

Going back to the laws of the universe again, kinetic energy is defined by the mass and the square of the speed.

Energy = power multiplied by time.

Power (engine or motor) = torque multiplied by rotational shaft speed.

So, again, we don't actually need anywhere near full power at low road speeds to accelerate quickly.

For an acceleration event to full speed, for a typical engine/gearbox combination, lets say 6 speeds, it is not physically possible for the first 3 gears to contribute more than about 25% of the total kinetic energy that the car will have at full speed.

What this says, counter-intuitively I suppose, is that ICEs with gearboxes are far from the ideal solution for acceleration.

To put this into graphical terms, I produced the chart below, for my own amusement, to compare a very high torque gear-less ICE (Koenigsegg Regera) with an Ultima theoretically fitted with the new Chevy 1000 bhp 10.3 litre V8 normally aspirated crate engine, and no gearbox. Theoretical in the sense that the engine might not actually fit that car, and I think you can't actually order one just yet.

Note that it would still be necessary to use something to disconnect the engine from the wheels at standstill, and because the Chevy engine is going to have quite a lumpy cam, I'm assuming a high stall speed torque converter would be fitted between the engine and the diff, which would still have a fixed final drive reduction ratio built in, like an EV. That way the engine can rev up into its higher torque band from standstill.

Exactly the same approach is taken with the Regera, it has a 5.5 litre twin turbo V8 augmented with (essentially) fixed torque electric motor assistance to increase acceleration. There is no multi-ratio gearbox, just a high stall speed torque converter and a final drive ratio.

The chart shows the actual instantaneous power to weight ratio of each car as a function of road speed.

There is only one curve for each car as there is only one (fixed) gear ratio between the engine and the driven wheels (ignoring wheelspin).

The Ultima has a final drive selected to hit a top speed of 186 mph (300 kph) at the maximum engine speed of 7000 rpm, the Regera has a maximum engine speed of 8500 rpm and is geared to reach a top speed of 250 mph.

The chart also shows the required power to weight ratio for both cars to maintain fixed 0.77G acceleration, targeted to match the 11 seconds it takes for the Regera to get from 0-300 kph. The required power includes drag and rolling resistance. These curves fully overlap at low road speed, and then diverge when the effects of drag become more apparent on the lighter car.

The actual power-to-weight ratio curves of the Regera and the Ultima are straightened using a high stall speed torque converter which allows the engine revs flare at low road speeds. This is apparent in any Regera acceleration run videos, where the engine goes straight to 5000 rpm and waits for the wheels to catch up. For the Ultima, I've set it at 4000 rpm.

And yes, I know this is a form of a 'gearbox' but it's not the same as trying to deliver full engine POWER at low road speeds through several lower gears.
It's a means of allowing close to the full engine TORQUE to be available at low road speeds.

If you try to apply full engine POWER at low road speeds in a 2WD drive car such as these, with equivalent engine torque values of 1200 Nm or more, there is insufficient driven tyre width to deliver the highly multiplied engine torque to the road. So the only solution is to either limit the engine torque in lower gears if you want to avoid uncontrolled wheelspin, or remove the gearbox and ensure the engine's peak torque is available at the lower road speeds, but don't multiply it, other than through the final drive. You also conveniently remove a large energy sapping device as well.

Exactly like an EV....

Which brings me to the Tesla Model S Plaid actual power-to-weight curve , shown for reference.

Now you can see why that car shoots off the line so fast, but will eventually be caught and overtaken by the Regera, and the Ultima.




TLDR:

Fixed torque at the road wheels, just like an EV provides, is the ideal solution for smooth, fast acceleration.

Applying full power at low road speeds is not necessary for fast acceleration, and is often counterproductive for high torque engines, particularly on 2WD cars.

Applying full power at low road speeds is not necessary for fast acceleration, but is often lots of fun for high torque engines, particularly on 2WD cars.

[off_again]

GT9 said:

Applying full power at low road speeds is not necessary for fast acceleration, but is often lots of fun for high torque engines, particularly on 2WD cars.

Science-speak for rolling burnouts? Hell yeah, thats fun!!!



And yes, I will admit that I didnt understand everything you wrote, but it is valid. The detail often makes the difference (and for me makes the whole car thing interesting) and when we are dealing with a world that is just interested in sound bites - we often forget that detail. Its like saying that drag racing is just about hitting the accelerator hard and keeping it straight - there are so many factors involved and it devolves to science so quickly.... its fascinating!

[GT9]

SWoll said:

It's the instant power ....

You said this before and it's a bit misleading.
The reason you are calling it instant is because the Plaid accelerates to 60 mph so damn quickly.
But it only does this because of the instant and continuous high torque available from zero to 60.
Being pedantic, I can access full power in my lowly ICE at 30 mph, whereas no-one can access full power in a Plaid at 30 mph, unless the wheels have broken traction and are spinning at the equivalent of 60 mph.

[Gary C]

you could even argue that its not torque, but the linear force developed from the torque at the interface between the tyres and the road that accelerates the car

Ie ? = rFsin(?)

so F = ? /(r sin(?))



But yes, force is what accelerates and torque is rotational force, however torque values are can be very misleading as you point out.

I can generate more torque at the crank on my pushbike than my Polo can, but the polo can accelerate far faster despite weighing a lot more, why ?, because it can rev and develop that torque as power, whereas I can only develop that torque from 0rpm to a fraction above that.

So we use power as a more useful comparison most other things being equal.

Of course, that graph of the Model S Plaid, shows constant power above 60 mph, so the torque and thus acceleration is falling.

Edited by Gary C on Tuesday 2nd November 22:58

[delta0]

EV6 GT is a performance hatchback. Taycan an electric 4 door 911 (maybe) and you want something more sporty then it’s the Rimac. The reality is batteries take up way more space so the car is going to be larger and higher.

Edited by delta0 on Tuesday 2nd November 22:59

[RobDickinson]

3 series is what 1mm lower than the model 3?

Current EVs are packaged in a way to take advantage of not having a large smelly lump of moving metal up front.

Their weight distribution and centre of gravity, and linear power delivery with the almost zero VNH they have has been the holy grail of car makers for decades.

[JonnyVTEC]

RobDickinson said:

3 series is what 1mm lower than the model 3?

Current EVs are packaged in a way to take advantage of not having a large smelly lump of moving metal up front.

Their weight distribution and centre of gravity, and linear power delivery with the almost zero VNH they have has been the holy grail of car makers for decades.

I’m pretty sure the 3 series has a more accommodating rear cabin space, not only a more comfortable posture, headliner above you head, easier ingress and vision as the roof structure isn’t ajacent to your head (hence the mental looking lack of tumble home on the side glass) and space for your feet under the driver. Don’t pretend the battery is invisible in a TM3