[WEC] BoP. Brilliant or Pants.

[Articus]

Originally Posted by PhilipR

BOP cannot equalise everything - I could see the Porsche a lot faster than the Ferrari in the Porsche curves, it could be that Porsche went for a bit more downforce that negated top speed, or the way they employ the hybrid could mean slower top speed.

Ferrari had the fastest S3 time of the entire race, 1 tenth ahead of the Porsche.



They were also ahead in S1 and S2.

.




Alpine was able to have great top speed for an LMDh car but it came with great consequence. They were very slow in the corners. You could see it in the onboards and the sector analysis. It was only the Ferrari and the Toyota who were the pace leaders in every sector without compromise. Highest top speeds, and also fast enough in the corners.



Basically in every single metric and calculation that I did, Ferrari was ahead of Porsche. You can look at averages of S1 times, S2 times, and S3 times over the entire race and it's all the same story. Ferrari was just faster. There was no sector metric where Porsche was faster.

The hybrid system doesn't have an effect on top speed. The petrol engine can supply the full power of the BOP table (a performance curve in the tech regs) at any point on the straight. Hybrid doesn't add power, it just replaces petrol power.

[Steve McQ]

Fastest doesn't mean much in an endurance race : we should be excluding the top 10 and analyzing the next 50 fastest sectors car by car to extract something valuable. It is not about peak but regular performance

[Articus]

Originally Posted by Steve McQ

Fastest doesn't mean much in an endurance race : we should be excluding the top 10 and analyzing the next 50 fastest sectors car by car to extract something valuable. It is not about peak but regular performance

Sector 1 Histogram:



Sector 2 Histogram (this is especially damning...):


Sector 3 Histogram:


Top Speed Histogram:




All data comes from the official timing website: http://fiawec.alkamelsystems.com/?season=13_2024 .
I have chosen to display the value field as percentage of the total number of laps done by each manufacturer otherwise the scaling is off due to the difference in the number of cars fielded by each manufacturer. There are two subsets to the data. The dry times and the wet times. These current figures are selected for the dry weather running.


Each individual manufacturer data set makes up a normal distribution ("bell curve"). You can work out by eye where the average lies (the middle of the bell for each manufacture). For the sector time histogram, the further to the left the bell lies, the faster the manufacturer was. For the top speed histogram it is the opposite. The further to the right the "bell" lies, the higher the average top speed of that manufacturer.

The Ferrari and Toyota are fastest in all sectors on average, but with a notable superiority in sector 2, the mulsanne. It's almost a 1 second deficit on average in the middle sector that the LMDh cars faced. This is actually worse than the race itself made it appear because of safety cars and mixed conditions keeping things close and LMDh cars getting a tow on the straights after being passed by a Ferrari/Toyota.


I can also show the wet weather distribution later.

[PhilipR]

Originally Posted by Articus

Ferrari had the fastest S3 time of the entire race, 1 tenth ahead of the Porsche.



They were also ahead in S1 and S2.

.




Alpine was able to have great top speed for an LMDh car but it came with great consequence. They were very slow in the corners. You could see it in the onboards and the sector analysis. It was only the Ferrari and the Toyota who were the pace leaders in every sector without compromise. Highest top speeds, and also fast enough in the corners.



Basically in every single metric and calculation that I did, Ferrari was ahead of Porsche. You can look at averages of S1 times, S2 times, and S3 times over the entire race and it's all the same story. Ferrari was just faster. There was no sector metric where Porsche was faster.

The hybrid system doesn't have an effect on top speed. The petrol engine can supply the full power of the BOP table (a performance curve in the tech regs) at any point on the straight. Hybrid doesn't add power, it just replaces petrol power.

Good analysis but sector 3 is not only Porsche Curves, also 2 long straights as well

To me it did look like the Porsche was better in the corners and in the rain it looked fastest (Vanthoor made up some 30 seconds in the rain in the night on the Toyota) - maybe they went for higher DF expecting the rain and then the overnight safety car screwed them

Listening to the Vanthoor post race podcast(I highlgy recommend) , Laurens did say in the rain he was able to catch up but once behind a car(this time the 51) the visibility was really bad and also lacked top speed which then led to losing temp in the front tires and could not overtake even if faster in the rain

Would be good next year to have a full dry and warm race to see the actual pace of the cars without much set up differentiators - though even then some will be better than oters inspite of BOP

[tomcug]

Originally Posted by Articus

The Penske cars didn't have much of a setup difference.

I'd say yes and no. The 6 looked like it had more downforce that the other two cars. In sector 2 the 5 was about 0.3 sec up on the 6 for the optimal lap while in sector 3 about a sec behind and looking at specific sectors that was due to loss in the Porsche curves. This isn't a proof of anything ofc but with the data available it looks like the high downforce approach was the best for LMDh cars anyway as with lower downforce laptimes were worse and they still didn't have much to fight with on the straights after Toyota and Ferrari showed their true hand and that happened only in the race, not even in the Hyperpole (excluding Toyota, no idea what the 7 would have shown there).

[PhilipR]

Originally Posted by tomcug

I'd say yes and no. The 6 looked like it had more downforce that the other two cars. In sector 2 the 5 was about 0.3 sec up on the 6 for the optimal lap while in sector 3 about a sec behind and looking at specific sectors that was due to loss in the Porsche curves. This isn't a proof of anything ofc but with the data available it looks like the high downforce approach was the best for LMDh cars anyway as with lower downforce laptimes were worse and they still didn't have much to fight with on the straights after Toyota and Ferrari showed their true hand and that happened only in the race, not even in the Hyperpole (excluding Toyota, no idea what the 7 would have shown there).

Higher downforce also means that they can warm up the tires faster. The reasons the Caddies and the Porsche were faster in hyperpole I imagine is because they could fire up the tires faster which was also helped by Vanthoor's red flag with some 8-9 mins to go.

[tomcug]

About tyre warmup, were their out laps quicker in the race compared to Toyotas and Ferraris? I didn't check this yet myself.

[Adam43]

Originally Posted by PhilipR

Higher downforce also means that they can warm up the tires faster. The reasons the Caddies and the Porsche were faster in hyperpole I imagine is because they could fire up the tires faster which was also helped by Vanthoor's red flag with some 8-9 mins to go.

Which is a very interesting nuance. Nice theory. BoP thankfully does not remove these interests. Although it can get in the way of understanding.

[PhilipR]

It did look to me that the Ferrari was losing time at begining of stint and after every safety car/ FCY restart

Toyota not sure - but they were not in hyperpole so we do not know how fast it could have gone. The 7 was on course for fastest lap in qualifying until Koba crashed

[Steve McQ]

Originally Posted by Articus

I can also show the wet weather distribution later.

Great job mate. Is there any possibility to put the average and median for each car on the graph so we can see the center of the distribution ?

[Matador]

Originally Posted by PhilipR

It did look to me that the Ferrari was losing time at begining of stint and after every safety car/ FCY restart

Toyota not sure - but they were not in hyperpole so we do not know how fast it could have gone. The 7 was on course for fastest lap in qualifying until Koba crashed

Half a second up at that.

[tomcug]

https://www.motorsport.com/lemans/ne...inst/10624619/
Bamber also not happy.

[PhilipR]

I mean if the aim of BOP is to make cars have same corner speed and same top speed might as well make it a spec series then

All these cars make their performance differently and some will have better cornering and some better top speed. Le Mans is a top speed dominated track and cars that aimed for that had an advantage (BOP even tried to address this via the power gain/drop after 250 kmh). Now unfortuntely for them the long Safety car overnight due to rain probably negated the higher downforce advantage that the LMDhs had - Vanthoor caught some 20-30 secs on the Toyota in 1 stint. The LMDh cars were not complaining bout BOP when their cornering speed gave them a big advantage in Qatar (the caddy was one of the fastest on par with the leading Porsche in that race). Also the Caddy and the Porsche were developed with IMSA racing in mind where cornering speed is quite crucial compared to larger European tracks . I want to see a sorted Alpine and their approach to top speed since they do not care about having car suited for IMSA

[Sodemo]

Originally Posted by Articus

To me, the reason we require BOP to begin with is because the ACO gave a wide performance window that the cars could be homologated at. Too large in my opinion.

You have extreme low drag concepts like the Ferrari trying to be balanced with more "F1 style" downforce cars like the Toyota, and then LMDh cars which are defined by styling cues, more than performance.


If they just placed a minimum drag level and max downforce level, and told everyone to show up within 0.1% of these numbers across the aero map, and also permitted rear wheel hybrid only, it wouldn't require much if any BOP.

Forgive me but isnt that what they have already done with LMH and LMDh? I thought all the cars were equalised on downforce and drag?

[Adam43]

Originally Posted by PhilipR

I mean if the aim of BOP is to make cars have same corner speed and same top speed might as well make it a spec series then

Yes. That is why we have what we have.

Originally Posted by Sodemo

Forgive me but isnt that what they have already done with LMH and LMDh? I thought all the cars were equalised on downforce and drag?

They are in the same ballpark, but they aren’t meant to all be the same under these regs.

[Articus]

Average Top Speed at Speed Trap for LM24 (selected values above 320km/h to remove nonsense data points).




The #4 Penske car looks like it was running less downforce than the #5 and the #6 Penske cars, but ultimately the #4 car was the slowest Penske car in the dry conditions which highlights the compromise that Penske had to make. Trimming their car out didn't make them faster overall. To chase top speed of the Ferrari and the Toyota, they would have made their cars slower overall. As a general observation, the LMDh cars have more tire wear than the LMH cars which is why it can be useful for them to run more downforce to better protect the tires.

[TF110]

It's strange seeing the Ferrari being so fast on the straight when they had a decent size power reduction and their bop had them on the lower end for total output. They have a slippery car, that's apparent.

[Adam43]

That’s why the ACO did the >250km/h thing!

[Adam43]

I’ll do the consistency lap time spread thing when I get back from holiday.

[Articus]

PhillipR for the rest of the data, I did a little bit of plotting of the manufacturer aggregated data (car wise data like the previous post is very tedious with excel...)

Sector 1 (average, deficit, standard deviation), based on all S1 times below 35 seconds.

[Adam43]

[Adam43]

I think these are more Le Mans race thread relevant rather than BoP.

It infers that this is down to BoP and that isn’t the intent of BoP and BoP is not the primary driver of these differences. That is all the us usual things you see in Motorsport; car design, drivers, strategy, set-up, tyre useage, conditions, etc…

[Articus]

Sector 2 (average, deficit, standard deviation), based on all S2 times below 82.1 seconds.

[Articus]

Originally Posted by Adam43

I think these are more Le Mans race thread relevant rather than BoP.

It infers that this is down to BoP and that isn’t the intent of BoP and BoP is not the primary driver of these differences. That is all the us usual things you see in Motorsport; car design, drivers, strategy, set-up, tyre useage, conditions, etc…

This is true. I should go ramble in there

[Adam43]

Originally Posted by Articus

This is true. I should go ramble in there

Not rambling. It’s good stuff.