What if? F1 vs LMP1 2014

[dougskullery]

To cut to the chase: given the changes in regulations for F1 and LMP1 classes in 2014, would a Le Mans prototype be faster over a grand-prix race distance than an F1 car?

This year's crop of LMP1 cars are producing around 1000bhp, which – with a minimum weight of 900kg – gives them a power-to-weight ratio of 1.11bhp/kg. In comparison, F1 cars in 2014 are producing around 780bhp with a minimum weight of 690kg, producing a marginally higher power-to-weight ratio of 1.13bhp/kg.

With 100kg of fuel on board, however, the advantage shifts marginally in favour of the LMP1 car, with a power-to-weight ratio of 1bhp/kg compared to the F1 car's 0.99bhp/kg.

On top of that, the top LMP1 cars produce more downforce than an F1 car (according to Alex Wurz on Twitter), with less drag. And Le Mans tyres can be run for far longer than F1 tyres, without a significant drop-off in performance.

This means that LMP1 cars can run much closer to their qualifying pace in races – at Le Mans 2013, the fastest race lap was only 0.2% slower than the pole time. In comparison, at the 2014 Malaysian Grand Prix, Rosberg's fastest lap was 4.1% slower than his pole position time.

F1 cars still have a 210kg weight advantage, which I suspect will give them a solid advantage over a single lap, and in a race their pit-stops would be quicker. But over a grand prix distance, I suspect that the LMP1's added downforce and superior tyre performance would make it a faster package.

Of course, I could be completely wrong about all of this – what are your thoughts? I suspect I've dramatically underestimated the impact of the weight difference…

[wesley123]

The issue about your 1000bhp calculation is that they do not have that power all the time, I believe it is 16 seconds per lap that they can actually enjoy this full power. The other time of the lap, they have much, much less power available.(I believe somewhere around 600bhp, even less I believe).

Also their weight is quite a big deficit in corners. So overall, an F1 car would still be quicker over the course of a lap, or even a race distance.

[sennaf1god.94]

The issue about your 1000bhp calculation is that they do not have that power all the time, I believe it is 16 seconds per lap that they can actually enjoy this full power. The other time of the lap, they have much, much less power available.(I believe somewhere around 600bhp, even less I believe).

Also their weight is quite a big deficit in corners. So overall, an F1 car would still be quicker over the course of a lap, or even a race distance.

In Toyota´s favour we´ve got 4WD, which is the definetive advantage to give the upper hand to LMP1´s thanks to bigger traction.

That 1.000bhp will be available on all four corners of the car during those 16,75 sec, while the 760bhp from F1´s will used mainly on the straights during 33,3 secs .

Also the bigger LMP1 engines produce more torque, which adds to their advantage during accelerations.

This weekend´s Silverstone WEC round will be pretty indicative...

[beelsebob]

I disagree that more torque gives them an acceleration advantage. We've already seen that the F1 cars have so much torque that they simply spin the wheels if you use it all. Adding more would not make them accelerate any faster at all.

[wesley123]

In Toyota´s favour we´ve got 4WD, which is the definetive advantage to give the upper hand to LMP1´s thanks to bigger traction.

Yes they have the possibility for that. However, the front wheels will be driven by electric charge. And still, they have to overcome 110kg's of added weight.

That 1.000bhp will be available on all four corners of the car during those 16,75 sec, while the 760bhp from F1´s will used mainly on the straights during 33,3 secs .

And the rest of the time it wil be limited to around 600bhp, the same as an F1 car. However, the F1 car has to run less time on only 600bhp of the lap, plus it has 110kg less it has to push forward

Also the bigger LMP1 engines produce more torque, which adds to their advantage during accelerations.

It has to push forward 110kg's more

This weekend´s Silverstone WEC round will be pretty indicative...

Agreed.


The whole issue as to why LMP's are still slower is their lack of power and their increased weight compared to an F1 car

[sennaf1god.94]

The whole issue as to why LMP's are still slower is their lack of power and their increased weight compared to an F1 car

Agreed.

And by looking into Paul Ricard testing times... LMP1´s look pretty much on the same level as last year. Maybe the track was too green, they might be 2 seconds faster this year at best...

While F1´s are 2-4 seconds slower this year depending on the track and tyres (Too conservative aproach by Pirelli)

For Silverstone I xpect a 1'40 pole lap from Webber´s Porsche, while I bet we´ll see a 1´31 from Hamilton´s Mercedes F1 (at best).

Sure on raceday the 9 second gap will be reduced to 5-4 seconds, enought to battle some Lotus, Marussia or Caterham.

[rscsr]

.....
And by looking into Paul Ricard testing times... LMP1´s look pretty much on the same level as last year. Maybe the track was too green, they might be 2 seconds faster this year at best...
.....

The main reason that the LMP1 have the same speed as last years test is that they are massively Sandbagging because they have to fear the BOP-mace.

[sennaf1god.94]

.....
And by looking into Paul Ricard testing times... LMP1´s look pretty much on the same level as last year. Maybe the track was too green, they might be 2 seconds faster this year at best...
.....

The main reason that the LMP1 have the same speed as last years test is that they are massively Sandbagging because they have to fear the BOP-mace.

How dare you!!!

Its´s all due to a green racetrack...

For comparison I used the LMP2 times, with an xpected progress of 1 second over a year, times were actually 1 second slower than 12 months ago. The track then must be at least 2 seconds worse.

The Rebellions also point in the same direction:

2013: 1:43.521
2014: 1:44.806 (same good old car, similar improvements as a LMP2 privateer: -1 sec)

So if we take the sandbagging factor into the equation... well we could see that Factory LMP1´s could be at least 3-4 seconds faster than last year?

Enought to get some points in a F1 race!



Off topic: the new Oreca built Rebellion has been unveiled today.

[bhall]

I don't see anything in the regulations that limits the duration of ERS use on a per lap basis. Instead, it seems total released energy is limited to 2MJ, 4MJ, 6MJ and 8MJ per lap, each value representing an ERS option that determines the car's maximum fuel-flow rate.



In any case, if LMP1 has a higher power-to-weight ratio than F1, four-wheel drive for better traction than F1, and more downforce for less drag than F1, it will outperform F1.

[Lycoming]

In any case, if LMP1 has a higher power-to-weight ratio than F1, four-wheel drive for better traction than F1, and more downforce for less drag than F1, it will outperform F1.

If you neglect the higher weight and the fact that the higher power-to-weight does not apply for the entire duration of the lap, then yes.

[bhall]

Where in the regulations is ERS power limited to a specific duration? All I see are limitations on total energy output.

[sennaf1god.94]

Where in the regulations is ERS power limited to a specific duration? All I see are limitations on total energy output.

Apparently the explanation is that simple:

I they are allowed 6MJ a lap and their electric motors generate 480 hp or 358 Kw I get 6,000,000 J / 358,000 w = 16,75 sec.

And F1 dont have 600 hp for the rest of the lap. They will always have a higher peak HP than the ICE can create on itself. They will use turbo compounding.

But I guess the guy was wrong.

With ACO adjustments, now the 6MJ petrol class has 139.5MJ per lap instead of the original 137.2MJ...

[bhall]

He's not necessarily wrong. It's just that a duration of 16.75s/lap assumes ERS release at max power. However, there's nothing to stop a team from using half the energy for twice as long.

[Lycoming]

He's not necessarily wrong. It's just that a duration of 16.75s/lap assumes ERS release at max power. However, there's nothing to stop a team from using half the energy for twice as long.

Which is still not the duration of the lap. Well, probably not in most cases.

To provide a somewhat even ground for comparison, what one could do is take the same track for an F1 car and a WEC car, say silverstone, determine time spent at full throttle for each car and divide ERS energy by that time, which gives you a power. Add that to the base ICE power, which is always available, and divide by the weight. Now you have numbers that you can directly compare.

Kind of.

It's not going to be a perfect predictor of relative straight line speed for several reasons, but that provides a better base of comparison in terms of power and weight.

I would grind out the numbers, but I have to study gasdynamics, and that involves enough number crunching as it is. If anybody else actually cares, it's not hard to do.

Also,

... more downforce for less drag than F1, it will outperform F1.

First, downforce/weight ratio is more important than actual downforce.

Second, to be clear, it is not necessarily more downforce than F1 AND less drag than F1. If we assume Wurz is correct and it's more downforce AND more efficient wrt. drag, that still does not necessarily mean less total drag overall.

Of course it's all moot since we'll find out for sure this weekend as long as the weather is merciful.

[sennaf1god.94]

He's not necessarily wrong. It's just that a duration of 16.75s/lap assumes ERS release at max power. However, there's nothing to stop a team from using half the energy for twice as long.

Well, then why not using the same amount of ERS time as a V6 F1 engine (33,33 sec) just for a fair comparison...?

LMP1: 600+241=841bhp (for flat out 4WD racing)

F1: 600+160=760bhp (for lifting & coasting 2WD racing)

So... the main questions will remain here:

Will the higher torque output compensate LMP1´s weight deficit?
Can prototypes beat F1´s top speed on the main straights even with DRS activated?
Is Wurz right and LMP1s generate more downforce... and so will they beat F1´s at Becketts?
Is 4WD really a factor in the medium-slow corners specially those from sector 2?
Will F1 Blend?