Ferrari LaFerrari vs Mclaren P1 vs Porsche 918

P1 is capable of applying 100kW of negative torque on the emoter when you lift off

 

+1. Not sure about the 0.5G figure though. Source?

 

Yes but negative torque becomes zero when the brakes are engaged, leaving the friction pads to do all work, hence the comment about longevity not being a given as a P1 win at this stage.

 

I'm not sure about that, as the engine is still running when you are braking and the emoter is connected to the engine. To clarify, the ecu controls the amount of negative tq , it is not always fixed at 100kw.

 

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To preserve brake feel, P1 has no brake regen during braking remember? What do you think that negative torque is? It's brake regen (e-motor braking).

 

Thanks.

Drift, right in that chart is another name for your negative torque - recuperation torque in Porsche-speak. As the e-motor converts kinetic energy to electricity, it provides a strong resistance (negative torque or recuperation torque) to the engine, thus braking the engine. Yes the ECU controls when and how much negative torque is applied - the higher the negative torque, the more kinetic energy harvested.

 

Negative tq is still there however it does not change when you press the brakes, no negative tq is added to help preserve brake feel.

Its a different system to the 918. You can call it brake regen on the 918 because it depends on actual braking. On the p1 the regen depends on off throttle, NOT the brakes.

 

kW is power unit, not torque unit.

Typically, most moderns engines perform fuel cut off when you lift off. The engine then is in motored state. In motored operation, "negative" torque of the engine a result of flywheel inertia, component friction, pumping work during compression etc . For a common engine, the maximum motored power (on maximum revs) i have observed in a dyno is roughly~25kW. This is a part of deceleration effect you get when you lift off and dont press the brake (you also have aerodynamic drag, friction etc contributing to that).

You understand that this is a fraction of the power required to keep the P1 battery-motor combination from depleting.

To my understanding, the energy required to fill the battery comes from the engine operating in extra load (thus burning extra fuel), in order to produce the extra energy. I am assuming that P1 engine may even burn fuel during off throttle- at least that why i assume from their commercialized graph below

TLDR: In the P1, all e-motor power you get in the form of e-boost during full throttle, is a result of extra fuel energy burnt in part throttle (and mayby eoff throttle) operation.

Maybe that's why Mclaren does not refer to their system as KERS, since the contribution of the "Kinetic Energy" factor is negligible.
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I think this has been discussed earlier and clarified

 

Now this is a rather blinkered view of the 2014 engine of the year award. Yes, it is true that McLaren's 3.8L engine V8 came 1st in the 3.0-4.0L category and 8th overall. What you forgot to mention is that Ferrari's 4.5L V8 came 2nd overall in 2014 and won the above 4L category as it had done in 2011 & 2012, this category had been won by Ferrari's 6.3L V12 in 2013. Ferrari's 4.5L V8 also won the 2014 best performance engine category (as it had done in 2011 & 2012), where Ferrari's 6.3L V12 engine came 2nd and McLaren's 3.8L engine V8 came third (!!!). This category, the best performance engine category had been won by Ferrari's 6.3L V12 in 2013. McLaren's 3.8L engine V8 had not won the best performance engine category in any year.

 

...and what?

Best Performance engine 2013:

1. Ferrari 6.3-litre V12 (294 points)
2. Ferrari 4.5-litre V8 (185 points)
3. McLaren 3.8-litre V8 (183 points)

Best Performance engine 2014:

1. Ferrari 4.5-litre V8 (289 points)
2. Ferrari 6.3-litre V12 (220 points)
3. McLaren 3.8-litre V8 (136 points)

Have a nice day, fanboy

 

It still didn't make it to the top 10 best International Engine of the Year. The V8 did, V12 didn't. anyway, it was just a response to someone else, no need to get all defensive.

 

Have missed that... So:

1. E motor support with e-boost, but not at full potential;
2. PDK strategy isn't as aggressive as in Race/HL;
3. Active aero is different;
4. Lights are in eco mode still, haha

For me, big difference...

 

That's weird. Because all the info up until this point, has said otherwise with the 918 faster (17.5 secs to 180 mph; 19+ for 186 mph by Sports Auto and Motor Auto Und Sports with a Weissach and Non Weissach car. P1 was 23+ secs above 186 mph. And no one else has come close to measuring it's upper speed, until this (cough cough) Autocar comparison.

So now sure where you were getting your info or your thoughts.

 

Brakes: 918 stops shorter 100-0, P1 has better brake feel, longevity untested.

Like a lot of these bench racing, magazine stats, a brake test from 100-0 in meters has to be taken in the correct context.

1. Braking to 0 is unrealistic on a track and should only really be looked at from a street perspective. For example, I just watched Treyon's 458C video and even the professional only slowed down to around 40mph over an entire lap at Laguna Seca. On the street it's much more common and much more important and I'll definitely give the 918 a big win in collision avoidance scenario. Would be kind of hilarious though if you avoided a fender bender up front by 5m, but rear ended by a Jetta who needed an extra 2m Not everyone has 918 brakes haha.

2. 5m is about 16.5ft. Using TG test as a basis, the P1 and 918 both reach 100mph in 5 second. This means that 100-0 is 4.5s and 4.4s, respectfully. 100mph is about 145ft/s. Fractions of a second lead to significant differences in distance traveled. 5m seems like a lot on paper and when you look at two cars stopped side by side, but again, you need the correct context. Most braking, especially on a track, is not nearly as scientific or consistent.

3. I could be wrong, but I'm pretty sure braking isn't linear from 100-0. Even if it was linear and oversimplified, you'd be talking about about a 1m difference in distance traveled for every second you were fully on the brakes. Couple that with the fact on a track you aren't braking to 0mph anyway, and the differences in braking distance between the two cars at any given corner shrinks considerably. I don't know about you, but I'm not sure anyone can meaningfully react to differences of 5-6ft at something like 60mph in the milliseconds it occurs.

I don't dispute the 918's absolute braking distance claims, but after thinking about it, I don't think it's really that important from the track performance context I mainly interested in. Shorter distance is always better, but such a statistic fails to tell you not only what happens through more realistic intervals, but also fails to illustrate the difference in makes on a track. I believe we'd really need to see the side-by-side video to see just how big of a difference there is. I think you'd also need to see 140-64mph, and 130-85mph, etc. 100mph is completely arbitrary.

For the reasons I've just stated, I don't think there is any real winner in braking at this point and you can only go based on opinion. I think it's extremely important to address the brake feel and longevity when discussing which car "brakes better" or "has better brakes." Brake feel has been addressed and they say the P1 is better, though that doesn't make the 918 bad. P1 could be a 10 and 918 could be a 9.

Longevity and consistency is what it would be nice to hear about and which we haven't really heard much.

 

Don't you think Porsche get to read the review and test results before the test gets confirmed for publication? If they were "lying" about the figures, wouldn't Porsche ask them to provide evidence?

 

FYI: Sports Auto and Motor Auto Und Sport, tested a Weissach and Non Weissach 918 at 19+ secs. Car and driver, tested the 918 at 0-180 mph in 17.5 secs.

So yes, these numbers are way off. But it can be some serious/British playing with words again.

Apparently, he said one is 'above 20 secs', and another is 'under 30 secs'. This could just be a play with words, especially considering we already know the 918 is faster in the upper limits, and SS's track record and ethics regarding these two cars.

It seems like McLaren's last hope to try salvage some (cough again) respectability for the P1.

 

Haha, working in the automotive industry from so long and given countless cars to journalists, I see the answer as NO...

 

You pick (cough cough) the one poor showing of the P1 as your source for the P1 results. How convenient. I guess it's also convenient to ignore that the SS was always way off it's expected time in that same test.

Now the same magazine tested them head to head and clocked it much quicker. Of course this time it's suspect because you don't like the results. Who'd have guessed...

Autocar is great when the P1 does poorly.
Autocar isn't credible when P1 does great.

Is that right?

 

Bang on! :-D

 

First of all, you're asking me to speak about the unknown (what Porsche does, and doesn't in this instance). So I don't understand your question. Nonetheless, I'll try to answer this Red Herring of a query.

It's been my experience, a manufacturer can't stop a magazine from publishing something. That's up to the magazine. The mag usually just reports whatever times they have. When their honest (a dubious word regarding many British mags), they may tell you what problem their vehicle had, hence increasing it's time, or whatever issue the manufacturer reported. But they don't stop the test. These things are done under time constraints, from both the manufacturer and magazines schedule, so those just don't happen on the regular.

By this/your logic, Porsche would have never given a car back to Sutcliffe after a review riddled with inaccuracies and "feelings", with no measurements. Even this test (by your logic again), Porsche would have "stopped the presses", because once again SS is dealing with highly ambiguous numbers (instead ambiguous feelings); stating "above 20 secs" and "below 30 secs". What does that mean (if true)?

My question: Why didn't McLaren, just give their P1 to Motor Trend when they requested it, instead of giving it to a third time to Autocar, and for the umpteenth time to a British Rag, I meant Mag?

 

Excuse me, it WAS THE ONLY SOURCE FOR THE P1 REGARDING HIGH SPEED TEST!!!
And in both their high speed acceleration, is with the same magazine, and above 20 secs.

So you're not really saying anything. Lol

Why don't McLaren give their car to a NON BRITISH MAGAZINE for a fully instrumented test or H2H.

That is the burning question. Not this nonsense.

 

Eh

Nothing here.

After The Harry Metclafe tweet, confirming the 918 was 1.5 secs faster on the track vs P1, and also TG hard published data, and (yet) unreleased, but talked about track numbers, you knew something like this was going to come up. No surprise.

Let the Cult Slurp The Holy Water, and Worship At The Alter.

Wake me up, when McLaren gives their car to a non British Mag for a H2H or fully instrumented test.

More Shenanigans.

 

Hold on a sec, I was siding with Porsche because the acceleration numbers were too slow compared to other mags and it should be faster, same applies to the P1 which should have been faster in their first test. So, my question was, wouldn't Porsche and McLaren get an early copy of the magazine in case they were reporting something that is way off, as seen in this case (except if these were the actual results) and P1's first test. I know they would... Thanks.