RE: Volkswagen ID.R attacks the Nordschleife!

[E65Ross]

I 8 a 4RE said:

It's not a lap record in any way shape or form if it has not been set in a race.

So if something gets around the lap of a track in record time, what do you call it?

[RDMcG]

mat205125 said:

Huge achievement, and massively impressive demonstration of the potential for EVs

I think that's correct...was an amazing thing to see.

If you think of any emerging technology it is often horrible. The internet was virtually unusable, mobile phones came in a suitcase with the old fashioned handset,PCs ran on floppy discs. Cars used to require constant maintenance when they first came to prominence and were horribly unreliable. Our world keeps changing and the new stuff is often more an indicator of potential than a fully developed solution.

[Turbobanana]

E65Ross said:

I 8 a 4RE said:

It's not a lap record in any way shape or form if it has not been set in a race.

So if something gets around the lap of a track in record time, what do you call it?

Rein in the laughter, Ross: it can be a "fastest lap" but not a "lap record" if it's not under race conditions, as I understand it.

[anonymous-user]

JD said:

After now watching the video, it seems even more like a missed opportunity.

It’s clearly a very very fast car, completely hamstrung by gearing or batteries (or both?)

240km/h down the big straight is pretty naff.

what? Perhaps you should have a go and show us how it's done eh? ;-)

[anonymous-user]

Jellinek said:

Curious to note that it easily hits 270 kmh early on but on the final straight it was hitting around 245-250. Was this drop in performance down to headwind, gradient or perhaps battery condition? Be interested to hear from anyone familiar with the track or conditions on the day.

There are three main factors at play in an EV with regard to long term performance at high speed (high motor rpm)


1) Mean battery voltage vs State of Charge (SoC):

All (practical) battery chemistries have a cell potential that falls with falling SoC. With an electric motors, voltage = rotational speed, so more volts = more revs, and as power is torque x revs, that means more power (i'm not going to go into the complexities of Field Weakening here, so that is necessarily a simplified statement, so don't bite me!) Therefore at the start of the run, with max SoC, we have max volts and hence max power. Typically, a modern cell will drop it's voltage by around 0.12% per % of SoC. This is therefore a tradeoff. More battery cells equals less drop for any given energy removed, but more cells = more mass to carry around



2) eMachine, Conductor & Battery Internal Resistance (IRb) vs temperature:

All things that conduct electricity have resistance (ok, not if they are superconducting, but for the purposes of this discussion we'll ignore that) The battery, and in fact all the current carrying infrastructure, including the windings in the eMachine, all increase their resistance (and hence looses more power / drops more voltage) as their temperature increases. For copper, that's about 0.4% per degC, for a battery (which has complex chemistry and electron paths) it's a bath tub shape and highly dependent upon the actual chemistry. So as everything heats up, your system losses increase, which for any given battery capability means less power at the wheels.


3) eMachine Rotor temperature:

Modern permanent magnet eMachines, especially those designed for high performance, use ultra high strength permanent magnets to provide the rotor magnetic field. Those magnets only "hold" their magnetic field strength below a certain temperature (it's called the Curie temperature if you want to google it). If their temperature exceeds the Curie point for the particular magnetic material used, the field strength collapses and your motor ceases to become a motor! Therefore, all eMachines include either measured or estimated rotor temperature models. As rotor heating (as opposed to stator heating caused by I^2R losses) is highly (rotational) speed dependent, operating the motor for sustained periods at high speed may result in the system limiting power to keep the rotor temperature below that vital "demag" point. Because the rotor of the motor is spinning, and is surrounded by the (hot) stator, it's hard to cool. The Integral Powertrain motors in ID.R are actually very good in terms of having both very low rotor losses, and use a (pretty trick!) system to dynamically cool the rotor, that is spinning round at up to 24,000 rpm! However, if you compare the short term peak rating (<30 sec) and Long term (continuous) rating for a typical modern eMachine, the continuous rating is usually around 75% of the peak. So long, fast straights are likely to result in a significant reduction in vMax as useable power tails off

[JD]

Max_Torque said:

what? Perhaps you should have a go and show us how it's done eh? ;-)

That’s not what I mean at all.

I just feel it’s clearly not demonstrating the full potential of what an electric car is capable of, so the project must have been limited from the outset.

So it’s, very well done for achieving what has been achieved from what the team had, but a shame it didn’t get to go further.

[sparta6]

E65Ross said:

Well for starters it's a race car, so, erm, yes...? Just like it would in any other race car.

Fairly certain a Le Mans GT racer would make it.

Not that it would be the most comfortable trip

[anonymous-user]

JD said:

That’s not what I mean at all.

I just feel it’s clearly not demonstrating the full potential of what an electric car is capable of, so the project must have been limited from the outset.

So it’s, very well done for achieving what has been achieved from what the team had, but a shame it didn’t get to go further.

Any evidence to substantiate that claim? How do you prove it's not the met the full potential of what an electric car is capable of over 1 lap of this circuit?

[JD]

mstrbkr said:

Any evidence to substantiate that claim? How do you prove it's not the met the full potential of what an electric car is capable of over 1 lap of this circuit?

Well the fact it was limping down the main straight at 150mph, can’t be a good sign?

[The Surveyor]

JD said:

mstrbkr said:

Any evidence to substantiate that claim? How do you prove it's not the met the full potential of what an electric car is capable of over 1 lap of this circuit?

Well the fact it was limping down the main straight at 150mph, can’t be a good sign?

Unless 150mph is the full potential of what an electric car is capable of...

[anonymous-user]

The Surveyor said:

JD said:

mstrbkr said:

Any evidence to substantiate that claim? How do you prove it's not the met the full potential of what an electric car is capable of over 1 lap of this circuit?

Well the fact it was limping down the main straight at 150mph, can’t be a good sign?

Unless 150mph is the full potential of what an electric car is capable of...

Precisely my point.

[thiscocks]

E65Ross said:

Housey said:

ajprice said:

Yep, about 6 seconds quicker than Stefan Bellof in the Porsche 956 in 1983.

Once again evidence, if it were ever needed, of what a lap that was by Bellof. Similar BHP, more downforce perhaps due to ground effects but still it was close to 35 years ago and the tech has moved on massively, not least tyres and traction.

the 956 was an awful lot lighter, I think. If you want to see how the game has changed in 35 years, think of how much quicker the 919 is to the 956.

I genuinely think that if they designed an EV especially for the 'Ring, they'd smash 6 minutes, whether they'd beat the 919 I'm not sure, but I am pretty certain it'd be a lot quicker than 6:05. They were just modifying a car they already had.

The 956 was 800kg so only 75kg lighter than the 919. As mentioned it will be mainly down to tyre and suspension improvement over time (not to mention the extra 400+bhp) . As also mentioned the track has had slight but not insignificant changes since then which make it faster.

Edited by thiscocks on Tuesday 4th June 12:48

[E65Ross]

thiscocks said:

E65Ross said:

Housey said:

ajprice said:

Yep, about 6 seconds quicker than Stefan Bellof in the Porsche 956 in 1983.

Once again evidence, if it were ever needed, of what a lap that was by Bellof. Similar BHP, more downforce perhaps due to ground effects but still it was close to 35 years ago and the tech has moved on massively, not least tyres and traction.

the 956 was an awful lot lighter, I think. If you want to see how the game has changed in 35 years, think of how much quicker the 919 is to the 956.

I genuinely think that if they designed an EV especially for the 'Ring, they'd smash 6 minutes, whether they'd beat the 919 I'm not sure, but I am pretty certain it'd be a lot quicker than 6:05. They were just modifying a car they already had.

The 956 was 800kg so only 75kg lighter than the 919. As mentioned it will be mainly down to tyre and suspension improvement over time (not to mention the extra . As also mentioned the track has had slight but not insignificant changes since then which make it faster.

Sorry, I thought we were talking about the ID.R, 800kgs vs almost 1200kgs....

[J4CKO]

Does the EV sort of run out of gearing/RPM at higher speeds, I know they dont need a gearbox in normal usage due to the power delivery characteristics but this isnt normal usage, would having some way of varying the gearing help.

Still cant get my head round the 919's lap record, also, lets not forget that the 919 is a Hybrid, with 400 odd bhp of its power coming from electric motors and the other 800 or so from a petrol engine. Part of its success is the fact that it has some power provided by motors.

Replace the engine with more motor capacity and it would be interesting to see what happens, suppose it depends on how heavy the batteries are.

Be interesting to see how things move on.

[E65Ross]

sparta6 said:

E65Ross said:

Well for starters it's a race car, so, erm, yes...? Just like it would in any other race car.

Fairly certain a Le Mans GT racer would make it.

Not that it would be the most comfortable trip

My point was that it's not road legal. Your second point brings it about the car being optimised for its own purpose, the ID.R was built for Pikes Peak, so it's not going to have batteries to last 100 mile flat-out stints. If it was racing for 100 mile stints like they do at Le Mans, it'd have more batteries.

[anonymous-user]

JD said:

mstrbkr said:

Any evidence to substantiate that claim? How do you prove it's not the met the full potential of what an electric car is capable of over 1 lap of this circuit?

Well the fact it was limping down the main straight at 150mph, can’t be a good sign?

er, a "lap time" is the time for the entire lap, not "how fast you drive down the straight! One of the reasons VW spent half a million on simulation for this attempt was to optimise the car to get the lowest lap time. In order to do that, there is a trade off between vehicle mass, energy storage capacity and aerodrag (to name just the top three major parameters) For the N/ring, that has lots of medium speed turns (typically around 90mph), you get a lower overall lap time by having a lighter high downforce car (high drag) to get you round 95% of the lap distance, and accept that you will loose some time (but less than you just gained) because you can't go as fast down the 5% straight bit at the very end. In an actual race of course, this doesn't work, because you'd be overtaken, but when racing just the clock, min total lap time is what matters (and is why all race series run "qualifying" setups that are very different from the setup used for the actual race.

To suggest that somehow, one of the worlds largest , most cash rich and most capable car companies, employing the worlds best engineers and applying the worlds best resources to this project was "sandbagging" is, frankly rather odd?

[cidered77]

RumbleOfThunder said:

Stick some modern rubber on Bellof's Porsche and this "record" seems somewhat underwhelming. Then again it's well known that electric motors with little to zero gear reduction struggle at higher speeds necessary for the ring.

The second fastest lap in the history of the world ever is underwhelming? The internet is a tough crowd eh...

Bellof's lap not on exactly the same layout, as has been pointed out. It also had a pilot whose staggering talent was matched only by his staggering bravery, which you might argue as being "beyond normal".

It doesn't seem credible a 30 year old tube framed steel braked racecar with the same driver would match this time on today's layout- even with more modern tyres .To put in perspective, a modern GT3 car does the equivalent of a 6:20-6:25 when they do the N24 race (can't do it exactly as they add the GP circuit also).

I think 15-20 seconds quicker than a modern factory run GT3 car is a more relevant and impressive comparison. The 919 lessso - that is literally the fastest car in the world....

[anonymous-user]

thiscocks said:

E65Ross said:

Housey said:

ajprice said:

Yep, about 6 seconds quicker than Stefan Bellof in the Porsche 956 in 1983.

Once again evidence, if it were ever needed, of what a lap that was by Bellof. Similar BHP, more downforce perhaps due to ground effects but still it was close to 35 years ago and the tech has moved on massively, not least tyres and traction.

the 956 was an awful lot lighter, I think. If you want to see how the game has changed in 35 years, think of how much quicker the 919 is to the 956.

I genuinely think that if they designed an EV especially for the 'Ring, they'd smash 6 minutes, whether they'd beat the 919 I'm not sure, but I am pretty certain it'd be a lot quicker than 6:05. They were just modifying a car they already had.

The 956 was 800kg so only 75kg lighter than the 919. As mentioned it will be mainly down to tyre and suspension improvement over time (not to mention the extra 400+bhp) . As also mentioned the track has had slight but not insignificant changes since then which make it faster.

Edited by thiscocks on Tuesday 4th June 12:48

Largest gain is in the extremely high L/D for a modern car that has been aero optimised in CFD and proven in thousands of wind tunnel hours. Back in the day, aero development was of the "change it and see if it's better or worse on track" category, today, we can run a thousand parameter CFD optimisation over night to get too 5 major optimisation sets, then run the vehicle in a full speed moving floor tunnel to pick the best one. Old race cars did make good downforce, but they were horrendously draggy in doing it!

[Lowtimer]

aarondbs said:

Just one lap before running out of charge??

It would be SENSATIONALLY stupid, when going for a single lap record, to carry any more battery than needed for the one lap at absolutely flat out performance.

[Robmarriott]

I can’t help but think they should have done this before Porsche. Imagine how crazy the internet would have gone if the outright record was with an electric car, despite how short a period of time that was for.