Ferrari LaFerrari vs Mclaren P1 vs Porsche 918

That's not correct and it has been discussed on McLarenLife. Owners who have driven their P1 quite extensively on the track and have made it clear that it does have 903 hp at all times. The engine always helps to recharge the battery when not full throttle.

 

Correct.

 

Regardless of what the 918's actually HP is (and we know Porsche has a habit of underestimating with their GT cars); the fact that almost 300 of it's horsepower is almost instant from the drive train, means it will have very little loss from for about a third of it's HP. And we also know, Porsche's usually have very little HP loss (compared to other brands), even when the HP starts from the crank.

I and other posters talked about this a long time ago, regarding some of the reasons why the 918 performed so well, broke the Ring Record (said "918 can actually have less listed HP than other two cars, but actually have more HP in the real world due to the electric motors affixed on it's axles").

This is the nitty gritty of much of this stuff a lot of over zealous fanboys of other competing brands simply overlook.

 

Mark, I was part of THAT discussion, and it went no where.

P1 only have 903HP when the battery has enough charge to give out and the car is not in charging mode. It only has one e-motor and it can either do a) charge the battery or b) provide traction duty. It cannot do both at the same time, quite different than the 918 where one can be charging, either regen or engine driven and the other putting down power.

As for it charges whenever full throttle is not called for, do you not think for one second that it still takes HP to run the charger? On a track there are rarely part throttle moment, one either is full on braking or full on throttle, precious time is lost if one is not doing that.

What you describe is that it opens up the throttle more than what's called for at the pedal and uses that extra bit to run the charger as needed, which means the 176HP from the e-motor is definitely NOT on the table and also a deficit of HP from the engine to drive the motor. So at any given rpm, the engine is not putting down what the engine power graph indicates. That really isn't a efficient way to convert gasoline energy.

P1 primarily is being driven on the gas engine, the e-motor is there to fill up the turbo lag at low to mid rpm, in short bursts, it isn't really being run full time until full throttle. Hence one only gets the full 903HP in selected times. Remember the P1 has a a lot smaller battery which can be drained very fast if the ECU is not careful in metering the power output.

That last paragraph is the reason why the heavier, less HP 918 on paper is able to be faster than the P1, P1 doesn't get all 903HP all the time.

The P1 doesn't have a HP meter where it display the HP output in real time, so the owners who have driven it on tracks may not be able tell whether is it being driven by 727HP or 903HP, especially with all the extra sensory input from the noise and the sensation of speed inside the car. They 'think' they have 903HP but hat may not be the case. 727HP on the P1 is almost the same as the Pagani Huayra, and everyone who has driven that car says it's super fast.

918 on the other hand, in Hot Lap mode, WILL lay down 887HP until the battery is empty, as it doesn't sap engine power to recharge, it only recharges using regen braking. It will however uses engine power to recharge like the P1 does in Race mode if it deem necessary.

 

My understanding is P1 does regenerative braking at off throttle moments except when driver steps on the brakes unlike 918 and LaF which do regenerative braking on off throttle moments including moments when driver steps on the brakes.

If I am wrong and P1 does zero regenerative braking and recharges exclusively by using engine torque, that's a waste of free energy and not a good implementation of hybrid tech. I believe McLaren is better than that.

 

Whoopsy,

I get what you're saying about the 918's ability to run in hot lap mode. I have no idea if the P1 is throttling its total HP output to keep the battery charged or not but I suspect it doesn't need to.

I asked one of the more experienced P1 owners at Spa last week about battery life while driving on the track and he said it's a 100% non-issue. From what he said I gleaned that there are so many opportunities for recharging the batteries (i.e. any time you lift, decelerate, brake, coast, etc.) that it finishes each lap with the same battery reading it started with and can go all day long as hard you dare drive it. The only time he's seen significant run-down of the battery is when driving it in e-mode (i.e. battery only).

BTW, that also seems to be consistent with what I witnessed when we test drove the car at Dunsfold. Every test session included an e-mode lap or two yet the battery would recharge as we drove the crap out of it in full hybrid mode (i.e. 903 HP available) and between runs it just sat idle on the tarmac without the engine running and without being plugged in. They did that all day long. When I asked about them not plugging it in (especially after running a few laps in e-mode) they said it wasn't a concern.

Of course the first lap or two with a customer in the car would have been pretty slow (learning the track and the car at the same time) so that's probably where the car did some massive recharging. But after a few laps in e-mode and a lap in "boost mode" (i.e. using only the gas engine with the electronic boost only provided when the IPAS button is depressed) I drove it as fast as my guts would allow in full hybrid mode (903 HP) until I needed a break and there was zero concern for the state of the battery. After that Brad Ellis (2007 British GT champion) got in a drove me around as fast as he could in full hybrid mode for a few laps and that was pretty exhilarating.

BTW the I think what you're saying at the end of your post about the 918 in hot lap mode is equally true about the P1. It will run as hard as it can until it deems the battery to be critically low, charging only from deceleration forces on the electric engine, and then it will recharge if necessary. I don't see why you think that's a feature of the Porsche only. I imagine the LaFerrari does the same thing.

Did you drive the P1?

 

We've seen acceleration tests of the P1 and it was as fast and sometimes faster than the 918. If you are coasting than you definitely wouldn't need all 903 hp to be used and if you accelerate again, the e-motor will give everything it has so the car can accelerate as it would with 903 hp. The car is only in charging mode when it's not using all 903 hp

P1 was optimized to be able to finish a full lap around the Nurburgring on full power. While it has a smaller battery pack than the 918, you have to keep in mind that it only has one e-motor which should not deplete the battery as fast as the two motors in the 918.

Now twice in a MT test, the 918 was not able to complete more than one or two laps (on different circuits) at full power in Hot-lap Mode, so in that regard, P1 has an advantage as it does recharge from the ICE in Race-Mode.

Bottom line is, it's not a 727 hp car with the e-motors only helping to fill the torque gaps. Whenever the car is accelerating it will have all 903 hp ready and when it's not, it will be using any surplus energy to recharge the batteries.

The only disadvantage that P1 has, is that it wouldn't be able to recharge its battery in E-Mode, since it doesn't have brake-regen. That's why it has a relatively lesser electric range and it's not all due to the smaller battery pack as many people think.

 

P1 doesn't have brake regen at all? You sure about that? Waste of kinetic energy if you are right.

 

Yes, McLaren did not go for regenerative braking because it ruins the brake feel (as seen on the 918 and LaFerrari) and you wouldn't want that on the best drivers' car!

 

I think you are wrong Mark. Ask Eric. He says P1 has KERS. KERS works thru regenerative braking (at the MGU). To avoid compromising brake feel, MGU brake regen stops the moment the P1 driver touches the brake pedal. In contrast, MGU brake regen in LaF and 918 continuous even when the brake pedal is pressed.

 

Sorry, was typing on the phone. I meant "did not go..." my bad.

 

AFAIK the P1 doesn't have regenerative braking. Regenerating under idle throttle is also a no go as this would slow the car down considerably, as is the case with electric cars.

Anyway, Ferrari has shown that it can be done properly.

 

I know you meant "not go" and I think you are wrong....So can someone confirm, does P1 have KERS or not?

 

Kers as in f1 style regenerative braking? Thank god it doesn't have that.

In f1 cars have to abide by regen rules hence the use of kers. This isn't f1, Mclaren have found a solution that works very efficiently without affecting brake feel.

Negative torque from the electric motor charges the batt at part throttle.

Genius really as you don't have that that weird disconnected brake feel, and you will never be able to deplete the battery in road or track. Unless your running e-mode.

Then you have charge mode, lets say you run in emode till you almost run out of bat. The engine restarts automatically. If you want a quick charge you just press the charge button and the battery gets charged in a couple of minutes.

 

Reviews said Laf had good brake feel compared to the 918 inspite of regen and only felt odd at slow speed meaning it wasn't an issue on the track

 

The P1 outputs 903hp all the times ! Unless you press the 'Charge' button to fast charge the batteries or press the 'Boost' button so you only have 727hp from engine and can use the IPAS button on streeing wheel for a full combined 903hp output.

The P1 uses the wasted energy when you lift the throttle specially in higher gears It won't act as a charger as long as you didn't press the button i mentioned earlier.

Mbn

 

They still thought it wasn't perfect though and these cars will spend most of the time being driven on the road.

P1 does recharge at part throttle and there's even a charge button on the fascia to drive at low speeds where it recharges the battery in a few minutes, as driftwithme said.

As for Ferrari have best implemented brake regen indeed and surprisingly better than the 918, despite seeing how much time Porsche have spent on trying to get it right. McLaren wanted it to be the best drivers' car on the road and on the track and it was a good decision for them not to adopt KERS to meat their objectives.

 

Doesn't need someone qualified in hybrid tech to confirm it. You already got the answer.

Here's an extract from McLaren's press release: "Energy, which would normally be wasted, is captured by the electric motor when lifting off the throttle, and harvested in the battery, especially in higher gears. The decision was taken to maintain a consistent feel during braking – crucial for performance driving – and for this reason, direct braking kinetic energy regeneration is not employed."

 

A cool thing about that charge button is that when used, and you pin the throttle, the engine feels like it decouples or declutchs from the transmission and spins to charge the battery. It still moves forward but feels like 80% power is used for recharging.

I use emode a lot and have tried this often, battery quickly recharges back in a matter of minutes.

However, no matter how hard I drive in the 900 HP modes, I have yet to see the battery meter move much.

 

Yes he said that and was wrong as usual but couldn't be bothered to argue with him

 

True.

 

Ruins brake feel?

Drive P 4/5 C or many other true KERS cars and report back.

 

Not.

 

Have you driven the 918 or the LaFerrari hard yet Jim?

 

Elaborate.