Ferrari LaFerrari vs Mclaren P1 vs Porsche 918

Hi REALZEUS,
I think what exoticcardreamer was discussing with his instructor was learning a car in 5 laps, rather than a circuit. I assume the driver for Thermal was already familiar with the track, just learning the braking points and downforce characteristics of each car which will vary, which is why they would take 5 laps to learn the cars.

I would imagine that if it is an unfamiliar car on an unfamiliar track, then it could take 15 or 20 laps for a pro driver to maximize performance.

 

As I already said the Ferrari power for BPR races comes from official sources and official books. In fact, the power was less, but they used a qualifying boost setting. The Mclaren’s figures comes from Autoweek magazine but they looks like officially dyno figures more than the disclosed ones. Rounded figures are just claimed figure. Just this. Aren't they?
According with the top speed extrapolated from the video using the block image and the length of Hunaudieres buildings, top speeds were more similar to 320 kph.

If you are patience please read back what I said: “I read somewhere a more realistic 7.45”. Post 20263, I never mentioned any McLaren book. You are who was putting it at stake. With the term more realistic I used, this does means that the figure would also improvable.

Then, being english not main mother-language honestly it’s difficult to me to find a technical error in a article unless I will translate it very accurately. It’s like asking you the same for an article wrote in Italian I think. Sorry but I have not the patience to translate an article that I have to pull out a detail that I’m not looking for. The only data I found strange at first was the weight, 1138 kgs were always sounds like a dry weight.

The reliability of a person comes from sources he entrust. I'm not the person that love conclude with no double checked sources, this is why I do not give to certain estimates and I have no interest in what other members done.

It's too much difficult give a value to an alignment starting from the F1 GTR. The GTR has so many improved suspensions details than the F1 road car that to me we cannot know. Usually track cars are 10 or more seconds faster per lap than road cars even restricted, so we are always unable to know from where the alignment improvement starts to where it ends. The same reasons the for tires, the downforce, ect... for every modded aspect. I will respect your opinion, but to me, there is no way to me to say that within 1s per lap was the figure to assign to an alignment because of the reason above. As you, I have my own doubts.

 

Okay,about 7:45 lap I recall that you said that in supercars forum in F40 Hamann vs F1 thread if you are the same F40 Le Mans,if you are not then I may have mistaken you for other guy.Judging from other laps I won't be surprised with 7:25-7:30(Estoril,Tsukuba damp,Goodwood).I also have done simulated laps for the same in Assetto Corsa with a good driver in the game.

And the article you showed about autoweek had some errors and I pointed them out in my previous posts.And regarding sources I too.And now about F1's Bedford lap concerns with other cars,I think I already explained about it in my older post,if you are unable to understand what I said then I am sorry,I am helpless.Now regarding Bedford lap,there is no way F1 with more downforce than CCX will be slower than it.

Also I never brought up F1 GTR in the bedford autodrome lap,sure an F1 GTR would be much faster than F1 even with road tires but that F1 had nowhere as mod as a F1 LM or GTR.In other words F1 LM would do much much better than 1;21.2 with a clean lap.1s improvement was for the #40 F1 not F1 GTR/LM.

As far as I know Autoweek was only source stating 662hp other reliable source I have only stated 600hp.So indeed I have my suspicion.

And now about the 1995 GTR,it had the same suspension as the F1 but it was stiffened for races but still it had more body rolls than other race cars if you look closely at the images of it.Thats why they chose different suspension in 1996 season.Okay,I think we should stop it here because I think we will never convince each other and lets peacefully and respectfully disagree.

Regards.

 

And that means reduced power, often seriously reduced power on 91 octane, relative to 93 octane (98 RON).

And you need to learn to read, I said 91 octane was 95 RON in the post you quoted. 93 octane is about 98 RON. Nobody in the free world runs a performance car on 95 RON if they can help it, only in Cali.

I think you'll find that car manufacturers do map cars for Japan LOL.

Your 4th paragraph makes zero sense, none, and shows a basic lack of understanding in physics and chemistry. Requiring more energy to detonate, means you can run more boost and timing without seeing detonation, and hence make more power.

Evo also did a test way back with a 996 Turbo that proves everything you've just written is nonsense.

 

A pro trying to shave time off their lap wouldn't be doing standing starts, which introduce a completely random and significant time variation in the first 400m alone.

 

I guess F1 drivers are not real pros since their races are all standing starts. Some F1 races are decided based on the start.

Why not use standing start? It is all part of a car's performance envelope. And for a road car in particular, there is a lot more starting from 0 than in actual race cars where you go lap after lap without stopping. We focus on lap times and sometimes forget these are road cars first.

 

Why not? A pro should be good enough to consistently launch a DCT car I'd think. Also, no pro would care enough about a street car to give two ****s about stressing over a lap time. Do you think Lebron James would give it his all in some pick up basketball game at his local playground? There's a thing called fun my dude. Learn it.

 

You really should talk to a petroleum engineer instead of just reading the internet 'bible' dude.

You really have NO idea how gasoline worked inside an engine do you?

For a given amount of gasoline, it has the same energy content from burning whether it is 87 or 91 octane.

The 91 octane just means it can withstand a higher temperature before combusting over the 87. The extra power from running a higher octane simply comes from an ECU permitting a higher compression, i.e. initial temperature inside the cylinder. More compression more power.

If an ECU is only tuned for a lower grade gasoline and is not tuned for the higher grade gasoline, the engine will not be running that extra bit of compression and hence no gain in power is realized. There is however a energy penalty to ignite the higher grade of gasoline from the spark plug.

The only time when a higher grade of gasoline will be taken advantaged of even when the ECU is not programmed for one will be in high heat condition, where the initial temperature will exceed the ignition temperature of the programmed gasoline, hence knocking. The higher grade will prevent that knocking and the engine will make whatever HP it is programmed to do.

After market race shop can re-program the ECU for say 100 octane race gas. They will give it a different fuel map and new compression tolerance for the extra octane. That's the only time higher octane gas will make more power, not from the octane but from the extra compression.


Well, Mycroft, here is your lesson for the day on automotive engineering. Seems like I am teaching you fairly regular in forums.

 

Also, the 918's compression ratio 13.5:1 ie race car territory. It would theoretically perform best given 100+ octane fuel (if the ECU was tuned for it). So not like it has this massive advantage over a P1 if both are running Cali's weak 91 octane junk gas. Both car's running at Thermal is just as valid as running anywhere else. Lieven can keep trying though....

 

Their qualifying laps don't.

Because if I'm a pro trying to shave off tenths and I do a lap where I've nailed a few corners perfectly and I'm expecting to have shaved 0.5s off my time, but then I find that the LC didn't hook up properly that time, and instead of being 0.5s faster, I'm 0.5s slower. LaF quarter times alone have varied from 9.7s to 11.2s. So you're introducing a completely random BS variable that's nothing to do with the driver or the lapping pace of the car.

Not at a track day there aren't. In fact there are exactly no standing starts, because you join the track from a speed-restricted pit lane.

Yeah, it was probably half-arsed laps, not really trying that hard, or for that long. Hence why they were probably flying starts and the laps were slightly slower than in the Harris test but they edited in a standing start, because that's TG's thing.

 

Even assuming the map isn't set up for higher octane and the timing and boost remain the same, the energy produced by the spark event has no bearing on the engine, it will be the same regardless of the fuel. It doesn't even know the fuel has changed. And the BTU of the fuel itself is likely the same. I think you'll also find the energy required to light a fuel-air mix is also very small, regardless of octane rating, but feel free to test it out with a lighter if you like.

However, all high performance cars are likely to be set up for all regular pump gas grades the world over and with Japan being the world's 3rd largest economy, I doubt they missed them.

Yes, you really are a veritable reserve of knowledge.

 

Some people seriously don't even think before posting. What is the dynamic compression ratio of a P1 running 1.4bar of boost.

Clue: It's 8.1*2.4.

NA engines are always less affected by heat, because the effect is doubled for turbo engines, not only is the intake air hotter but it degrades intercooler efficiency too.

Besides that, the 918 produces a much larger % of its power from a non-IC source, that's independent of fuel and heat (except that the battery died after the Thermal test and needed replacing). This is why it always looks better than it really is in Cali tests.

 

A car launching from start is definitely part of it's overall performance. If the LC system is crappy and inconsistent, why should that be ignored? Road cars are more likely to launch from a start than a track car, so it should be part of the overall test.

 

You're correct using the simplest formula you could find on the internet. However, let's look at it like this. While I'm not going to argue that under boost the Mclaren is theoretically running a higher CR than a NA engine (hence why boosted engines really like race gas, also there's lots of environmental factors which the formula you used) my point was to say that using 91 vs 93 Octane, which is roughly equivalent to 98 vs 100 in your England, that both cars would suffer a negligible amount. Perhaps the P1 slightly more but in all reality their isn't much difference. Now, if we are talking about putting 105 octane race fuel in both then the P1 would benefit more (especially if the ECU was mapped for it) but the 918 would like the fuel as well. If the turbocharged engine in the P1 was designed to work with 91/93 octane, which it was as Mclaren understands it's a road car and they are a great company, then the car should be making near full power on 91 octane just like the 918 (which will also be slightly down). If they just cranked up the boost psi on a 12C and knew that the engine wasn't going to run properly unless 100 octane fuel was used shame on them.

Running both cars at Thermal is just as valid as anywhere else.

 

Well since it's a weakness for the P1 it clearly can not be considered. All laps must be from a non standing start, ambient must be between 70-72 degrees, P1 must have on brand new Trofeo R's, and track must not have any second gear corners. Any test that doesn't meat said criteria is obviously not valid.

 

Only if you're an imbecile who races people from at stoplights on a public road. On track days you start from a rolling start leaving the pit lane, absolutely nobody starts from rest on the start/finish line.

If you want to measure standing start acceleration, you do it in a separate test, not a hot lap test. You know, like everyone else does. Not that I believe they really used a standing start, which was my original point. This is just an explanation of why they wouldn't used one.

BTW, all LCs can be crappy an inconsistent, which ironically they proved prior to the lap test during the same Grand Tour episode. So when you measure a hot lap, you wouldn't know whether the end result demonstrated handling performance, or simply one car doing a good launch vs another car doing a bad launch. Hence why it would be a crap test regardless of whether they really did a standing start or not.

 

91 octane is roughly equivalent to 95 RON. 93 octane is 98 RON. We have up to 99 RON at the pumps. In fact an odd few BP garages do 102 RON but that isn't common. 95 RON is for Fiat Puntos.

Actually the difference could be anywhere from 5-10%, especially if it's hot. A C7 Z06 originally put in a very bad time at MLRS too due to similar issues. No point testing cars in limp mode either. In all honesty, tests at 130degF are about as relevant as lap times in the snow at 0degF.

It may make the claimed hp on 91 octane but it will make more on 93oct/98RON and more still of 102RON. And since 91oct is pretty much only a Cali issue, nobody outside of Cali really cares what happens on 91oct.

 

Does anyone apart from Clarkson run hot laps from a standing start?

Evo? MT? C&D? R&T? Autocar? Sport Auto? Autozeitung? AutoBild? CAR? AMuS? Motorsport Magazine? Option?.........

Seems to me there's a very broad consensus for not running hot laps from a standing start, not that they really did anyway.

 

That's a great question. I have no idea. Looking forward to some answers.

 

Aren't you a lovely potato!

Of course the car will know the difference in fuel. Don't you realized modern cars have O2 sensors in the exhaust stream too? That's for monitoring the combustion process in addition to the knock sensor. If the ECU expect one grade of fuel and the sensor readings tell it the combustion process is not spitting out the expected stream of exhaust, the ECU will correct for it. Running say 100+ octane fuel in a car not programmed for, means the fuels are not igniting at optimal temperature, the exhaust gas composition will be different, and the ECU will know to increase the spark intensity, which also draws more current, and a high drag on the alternator.

Since the ECU is not programmed to take advantage of the increased knock resistance of the higher grade fuel, there is absolutely no performance benefits.

Most manufacturers programmed their ECU tailored to the specific countries the cars are expected to be sold at, a car sold in North American will not have the programming to take advantage of Japanese fuel grades. Same with European market cars that won't have the programming for North American or Japan or China or wherever. Maybe McLaren will do it just so they can save money on individual market customization, but that's not how everyone else do it dude.

 

One of the biggest AMuS databases of lap times is actually from standing start. Pro driver and full telemetry analysis.
TG also use this...
Flying starts are used for safety reasons and easier organising, imv...

 

Forza does so by default. Just FYI.

 

And why would it not be igniting at the optimal temperature? This should be good.

If the O2 sensor in a modern car did detect less oxygen (incomplete combustion), it would lean out the AFR, which would increase power, unless it detected knock. The voltage across the spark plug gap is determined by the coil pack circuit, which works off the MAF. When on boost, drawing in a greater mass of air into the cylinder, the voltage is increased.

That's basically why most large, modern car manufacturers would do it. Why develop two or 3 different programs to essentially do the same thing, when you can design one to do it all.

 

TG is basically Clarkson's legacy. Which AMuS track do they test from a standing start? None of the German tests I've seen at Nordschleife, Nurburgring GP, Hockenheim Short or Hockenheim GP do. Ditto for Contidrom and Sachsenring.

When you're already doing separate 0-XXXmph acceleration tests, there seems little point in watering-down and confusing lap performance by including a standing start. The average track day goer, attends a track and comes out of the pit lane rolling, so I don't see the relevance of a standing start. Even in pro racing, only one out maybe 70 F1 laps in a race is from a standing start. Ditto for endurance racing. And when you're putting in multiple laps to shave time, standing starts are both inconvenient (hence why I doubt they really used one) and inconsistent.

 

So long as they compare all of the cars in a test by whatever standard, the actual standard doesn't matter. Expecting to be able to compare tests across such a wide spectrum is only ever going to end in disapointment as there are too many variables to take into account.