42 Hyper car battery comparison

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A topic that's been debated until the cows come home but we finally have cast iron proof.

Back-to-back lap battery comparison, Porsche 918 in "hot-lap" Mode at Sebring Short (onboard) versus McLaren P1 in "race mode" at Circuit of the Americas (onboard). Both videos begin on out-lap.

Sebring and Circuit of the Americas are similar length, in terms of time. Here is how top speed varies lap after lap on 2 longest straights:

Porsche 918: lap 1 - 151 mph and 165 mph, lap 2 - 146 mph and 148 mph

McLaren P1: lap1 - 175 mph and 161 mph, lap 2 - 178 mph, 163 mph

The 918 is dying 2 minutes and 50 seconds into hot-lapping, the P1 is still going strong after 4 minutes and 40 seconds and can reach 162 mph in third consecutive flying lap.

8y ago by sroser
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sroser  8y ago

The problem is that the other one shows the wrong track layout at T7.
https://media.fastestlaps.com/sebring-short-2.jpg?
https://media.fastestlaps.com/sebring-international-raceway-2.jpg?

In order to fully fix the problem:

1) The correct track diagrams should be added to Sebring International.
2) The P1 time should be deleted - not a complete lap, edit at 2:53 in video.
3) Delete Sebring Short.


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lafars  8y ago

"Anyway even if fastest laps has historic tracks,it doesn't change the fact that Lieven introduced Sebring Short only to avoid putting it in the same leaderboard as other 2 cars."

"The track name of Sebring International is correct.If you want to add the larger circuit why not name it Sebring International 1998.That way it will be correct,besides what will be the point of adding that track with no lap times.There is no track named Sebrkng Short,so there itself you are wrong.Besides the map clearly mentions 17 corners,so it is indeed referring to newer track."

-Mclarenf1gtrlm, Fchat

sebring short shouldn't be on the site


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sroser  8y ago

It didn't work with this url, it auto converted half of it and left a bit for some reason. The actual url had a space. Anyway, I've directly linked the image now.


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FastestLaps  8y ago

FL does have 99 coding issues but this b**ch aint one. It's incorrect URL. URLs can't contain spaces. Besides, you don't need to wrap those in "[url]" BBCode tags, because this forum supports markdown and links are turned into hyperlinks automatically anyway.



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manone  8y ago

[url]https://www.dropbox.com/s/ruo1zactr9jbro4/2017-02-07 (1).png?dl=0[/url]

this link gives a 404 error, which is exactly what you return whenever
one asks about any evidence of your nonsense bullcrap.

the other links to mclarenlife site, just contain your usual creative dung only posted under different nicknames. it hardly provides anything useful.

the graph you managed to embed does not specify what's on the
x-axis. i extrapolate from the context that it is time, but that would show 918 to be slower than P1 at MRLS and there is no scale, so it is impossible to accurately say what is the range of the graph, you state to be multiple laps. Since there is NO periodicity apparent in the graph, i derive the x-range is (a part of) one lap at MRLS. This implies the x-axis range is 1.30 min
maximum. Now, what do you claim this graph shows about P1 recharging abilities?

Ask him yourself Manone, registration is free.

lol. It is you who claims that elephans fly, thus it is your burden to provide some evidence of that, which is, i remind you, data of el. energy generated by mclaren motor. Unfortunately, your "malaren did it, hence it must be the best" argument, which may work for some "normal" people and normal mclaren fangirls, usually is not a very convincing one for most others.


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BR2+  8y ago

Still won't outlast an energizer...



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BR2+  8y ago

....Normal?..


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sroser  8y ago

Ask him yourself Manone, registration is free. But for me and anyone normal, this answers the question.

http://www.mclarenlife.com/forums/mclaren-p1-f1/58306-mclaren-p1-vs-porsche-918-spyder-both-trofeo-r-tyres-4.html#post1313842

Aside from that, there's this Laguna data, showing a session of 8 laps. You can also see from the sector deltas vs best P1 sectors that there was a spare 1.17s in there.

You have no time to download simple software, yet you can post long bullshitty replies all day long?

[url]https://www.dropbox.com/s/ruo1zactr9jbro4/2017-02-07 (1).png?dl=0[/url]

And this graph.

550x800m


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manone  8y ago

you are still providing NO data nor evidence of any figure on how much el. energy P1 generates in an average 1 min track session.
hence, you are just trying convince people to believe in aliens invading the earth.

No mate, under braking and under part throttle the P1 charges the battery direct from the engine in the same way any generator does. The e-motor works backwards basically.

as usual, you are blabbing of things you are clueless: i am afraid it is not enough to have a powerful ICE and a motor/generator within 1 meter one each other to generate electricity...

I just did you clown, look at the Laguna data I provided which has been posted on several forums as lap times. When Randy Pobst was trying to do a faster lap, he did about 5 hot laps with recharge laps in between. JFC, you don't even read the ****ing posts you're responding to.

lol, i simply have NO TIME to search for/download/install a software to read a text data file in some weird format. if you want people to read some file make sure it is readable by some million users at least by double clicking on it.

Now shut up with 4-5 mins then pit crap. It's 4-5mins, then cool down lap, the 4-5mins. Pitting to cool down isn't even sensible.

lol, that's called "cool down lap" not "recharging lap". Ask that user to provide battery recharging data during "cool down laps" AND "hot laps". than we can talk.


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sroser  8y ago

There:

http://www.mclarenlife.com/forums/mclaren-p1-f1/58306-mclaren-p1-vs-porsche-918-spyder-both-trofeo-r-tyres-4.html#post1313842

Now shut up with 4-5 mins then pit crap. It's 4-5mins, then cool down lap, the 4-5mins. Pitting to cool down isn't even sensible.


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sroser  8y ago

Well you can say what you like Manone but a driver who has driven both on Silverstone regularly says the P1 GTR lasts twice as long as the LaF FXX K. So no explanation you give is valid.

No mate, under braking and under part throttle the P1 charges the battery direct from the engine in the same way any generator does. The e-motor works backwards basically.

I just did you clown, look at the Laguna data I provided which has been posted on several forums as lap times. When Randy Pobst was trying to do a faster lap, he did about 5 hot laps with recharge laps in between. JFC, you don't even read the ****ing posts you're responding to.


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manone  8y ago

Braking wastes a lot of KE as heat, which is why brake discs glow.

you can easily produce that heat with less than 50% of the KE lost in a braking section. the rest goes towards recharging the battery.

It's a 737hp engine, pretty sure that can generate energy very fast

absolutely NOT. that engine is not at power-generating disposal when braking, nor the gearing is correct, nor the rpms. power generation, if any, happens just by increasing ICE load while braking, i.e. almost insignificant.

You're the one who needs to quit blabbing, the P1 can do 2 laps of Silverstone in a row before a cool down lap,....
The P1 does not have to pit after 5 minutes, where the hell does it say that?

until you provide some data showing how much electric energy P1 can recharge per minute, there will be no such a thing as "a cool down lap to recharge" for P1. P1 will have to pit and plug in to recharge. Unless it can recharge when ICE accelerates, as well, but this is not the case, as it seems.
From what you keep quoting, P1gts battery is completely out of
juice after 4-5 minutes of track time (otherwise why would it need to slow down, since it has much less battery overheating issues), which implies the recharging you keep blabbing about simply does not happen in any meaningful way.
with brake regen, P1gtr would still have some kwhs at its disposal after 5 min of track time, hence no need for slow laps because of power unit in that case.
Fxx-k does not need to pit, it just needs to cool down the battery, more so than P1, and it can do that by using less motor power (since apparently it cannot completely exclude motor power outputs), which can be done just by slowing down. FXX-K has 4 modes to do that: each has different schemes of motor use/generation. The "fast charge" mode is the one that allows to least use of the motor for power output. I bet those writing about alternating 1 hot lap and 1 slow, switch from "qualify" mode and "fast charge". with "long run" one should be able to run indefinitely.


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sroser  8y ago

Not so. It's a 737hp engine, pretty sure that can generate energy very fast. Braking wastes a lot of KE as heat, which is why brake discs glow.

Learn to read, link provided says the following.

Best case you can repeat that for a couple of laps until the batteries overheat. I have not on a single track managed to do more than 3 hot laps in the FXXK, (1 HL, 1 Cool down, 1 HL, 1 cool down, 1 hot lap, and back into the pits). The P1 GTR is slightly better, and usually gives you 2 hotlaps in a row before you have to recharge and cool down.

You're the one who needs to quit blabbing, the P1 can do 2 laps of Silverstone in a row before a cool down lap, the LaF can only do 1 consecutive lap. Ditto for the 918 at Sebring. The P1 does not have to pit after 5 minutes, where the hell does it say that? Motor Trend released some data showing that they did 8 or 9 laps of Laguna with intermittent recharge laps before pitting.

https://drive.google.com/folderview?id=0B7qN2LFTlsktfmptWGlSbURjZXRFVVR3MENNRTFzTzBLQ3RXRk4tT3ZuQnExSkZRa1lMRk0&usp=sharing


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manone  8y ago

What you need to ask is whether the LaF and 918 can recharge from the brakes at the same time as they recharge from the engine, because otherwise it probably isn't any more efficient, since a lot of KE gets wasted as heat during any braking scenario.

There simply does not exist any way of recharging car's battery except by reversing the motor to function as a generator.
in regenerative braking the energy comes from the KE loss. If mclaren uses just the energy produced by the engine by increasing its load, during the same braking time, that ends up being just marginal, *much less" that the KE loss, as engine's rmp and gearing cannot be arbitrary.
Even if the engine would be fully employed at its max power to reverse the motor (which is FAR from being the case), the energy would still be inferior to KE loss, when a pro pilot drives flat out.
Now, please provide some data on the energy recovered by P1 every minute. Non mclaren-fan-girls need them, blabbing is not enough.
All we know is that p1 gtr have to pit after 4-5 minutes of track time which is consistent with NO energy recovery from P1:
typically, one is roughly at 50% WOT time during a track session, which means 120-150secs WOT and precisely 130 secs is what it takes to fully discharge P1's 4.7kwh battery at 131kw power. That's as spot on as it gets.

http://www.mclarenlife.com/forums/mclaren-p1-f1/58306-mclaren-p1-vs-porsche-918-spyder-both-trofeo-r-tyres-4.html

there is nothing in the link you provided, moreover you quoted different information from those you posted few days back. meaning you do not know what you are talking about as usual. "recharging" for laf means driving slightly slower. "recharging" for P1 means plugging it to the outlet. you just overlooked at this marginal detail...lol

laf can run indefinitely, provided it takes a slower lap every 1 or 2,
because it actually recharges the battery by (very roughly) 1kwh per minute and at lap 20, back to back, it will still have 963ps at its disposal for few teens of seconds. P1 will have to recharge at the outlet, which means pitting, should you wish to use 900ps.


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BR2+  8y ago

Yall write too damned much.


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sroser  8y ago

129secs=3600secs/(131kw/4.7kwh) are you going to argue about that? if the car runs the motor for longer it is because it does not use full power.

You're neglecting recharging from the engine under braking and part throttle. Otherwise, for Ferrari.

[2.300/120]*3600 = 69s.

For 918 in HL Mode.

[6.8/~270]*3600 = 90s

What you need to ask is whether the LaF and 918 can recharge from the brakes at the same time as they recharge from the engine, because otherwise it probably isn't any more efficient, since a lot of KE gets wasted as heat during any braking scenario.

Dude, before you spout complete crap about the LaF not needing to pit, read this thread.

http://www.mclarenlife.com/forums/mclaren-p1-f1/58306-mclaren-p1-vs-porsche-918-spyder-both-trofeo-r-tyres-4.html

1 lap at Silverstone for LaF before recharge lap, 1 hot, 1recharge and 1 hot again and then pit. For P1 GTR, 2 hot laps, recharge then 2 more etc. At Fiorano, 1.5 laps for FXX K before recharge lap. These are cast iron facts directly from a person who owns the LaF, LaF FXXK, P1, P1 GTR and 918. Sadly he doesn't track the 918, so we have no info there, but it does last longer during road driving because it has a larger battery. These are all facts, non-disputable.

The P1 has 2.045 times the battery capacity of the LaF (4.7 vs 2.3kWh) and when the LaF is using brake regen, the P1 is recharging direct from the engine, with far less energy being wasted as heat. The assumption that brake regen gives better hot lap endurance doesn't hold up in reality.


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manone  8y ago

BUT battery technology has moved on massively from when they designed the cars, so they should be able to either/or reduce battery weight while keeping capacity the same or increase battery capacity in the same weight and size requirement.

this is false. battery technology is extremely slow evolving, because it is very complicated to. Greatly improving energy storage capabilities would arguably represent the greatest scientific breakthrough in human history, with consequences much more relevant than hybrid applications. The technology to make "better"=higher specific energy batteries than those used in these hybrids has been there since years. Indeed tesla uses it. maybe other aspects have been evaluated by porsche ferrari and mclaren.

There are two ways of reducing heat, one is cooling, the other is lowering current. The problem with lowering current is that it means less Torque, but I believe the P1 (and maybe the LaF(?)) has a separate 2:1 gearing on the e-motor to step up the torque.

besides actively (possibly liquid) cooling a battery. you could halve discharge current RATE c (which is what heats the batteries, not much the current per-se) by doubling battery capacity and keeping the same torque at the same time, should you wish.


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manone  8y ago

130s my arse! This is the longest 130s I've ever seen.

129secs=3600secs/(131kw/4.7kwh) are you going to argue about that? if the car runs the motor for longer it is because it does not use full power.

You're missing the obvious here. The P1's battery is more than twice the size of the LaF. And we have a concrete statement from Alexander West that the P1 GTR lasts twice as long as the FXX K on Silverstone between recharge laps.

the "only" (very important one though) practical consequence, along with the relatively low motor power, is that it runs cooler than laf. laf does not need to pit at all because it constantly recharges the battery. after just 2 fiorano laps laf has initial charge+brake regen. higher than total P1 battery charge. Laf cannot run at full el. motor power indefinitely probably, even without battery overheating problems, but in a e.g.15-20 minutes track session it can use a total of at least 4 times P1's electric energy, which is huge. The same goes for 918 which has regen as well.