[WEC] BoP. Brilliant or Pants.

[Simmi]

It's easy to forget how bad the current Toyota looked in that first season. The competition level just let them off the hook.

[joeb]

Originally Posted by Adam43

Generally I like it. It feels more endurance racing.



Obviously in extreme conditions the restrictions can backfire, and equally just allowing infinite tyres can make it too easy.



But on balance I like it. Being able to double or triple stint tyres well should be a potential strategy. Or choosing to change only two or three.



I’d potentially tweak the rules so that changing tyres took even longer.



Would need to crunch some numbers to see whether this is reasonable, but I’d look at it.

I agree with you on the ability to affect your own strategy by deciding how many stints to run your tires, or if you want to change them every pit stop. But like you said there has to be some advantage to not changing them time wise. And as the rules are now, we don't get that big advantage.

[chernaudi]

It was that way until 2006-2007 when tire pick up really started to effect performance to the point where you often lost time not changing tires as often as you could. Oddly, at least one race in 2008 was won by double stinting tires (Mid Ohio ALMS). Also as far as strategy, Audi stuck with double stinting tires at LM (when the could at least at times do triple stints) because then they could quadruple stint drivers instead of triples for both.


Of course in 2011 they did do 4 or even 5 stints on tires with the first R18, and often did 4 in 2013.



I think the only way you'd get back to teams voluntarily double or triple stinting tires in the sprint races is if we go back to using one wheel gun at a time during stops, but we all know that most teams used 2 or even sometimes 3 total during the stop, so the ACO reverted (after several years) to pre-2009 pit rules.

[veeten]

That was because back in the early 2000's, the Michelin tires had such a great build that you could do multiple stints with them and have near perfect wear patterns. After Audi showed that you could, practically everyone was doing it. Other tire makers tried, but no one had the Mishies beat.

[TF110]

The cars today are 150kg+ heavier and lower on the downforce. So it's easy to see why tire management is harder. I don't like the rules making the cars so heavy and pushing them to double stint for conservation sakes is also silly imo. But I'm not the rule maker.

Once these teams study in the off season they will be better.

[Sodemo]

I’d like to think that in a few years (providing the Hypercar rule set doesn’t collapse) there could be scope for a min weight reduction…?

[J Jay]

Originally Posted by Sodemo

I’d like to think that in a few years (providing the Hypercar rule set doesn’t collapse) there could be scope for a min weight reduction…?

Weight reduction is very resource intensive, and given the focus on keeping something of a lid on costs (and lap time), a small power bump is more likely.

[tomcug]

Originally Posted by Sodemo

I’d like to think that in a few years (providing the Hypercar rule set doesn’t collapse) there could be scope for a min weight reduction…?

No way most likely, ruleset was made that way to reduce costs as J Jay already mentioned.

Originally Posted by J Jay

a small power bump is more likely

For sure, Glick was already running with more power than theoretical limit at Monza last year

[joeb]

Originally Posted by J Jay

Weight reduction is very resource intensive, and given the focus on keeping something of a lid on costs (and lap time), a small power bump is more likely.

Agree, but would also like to know if any hypercar teams are carrying ballast to reach minimum weight.

[Gerard C]

Originally Posted by joeb

Agree, but would also like to know if any hypercar teams are carrying ballast to reach minimum weight.

Before they are BoP'ed hard to know for sure. Interesting question imo.

[Sodemo]

I'd have thought most cars are built underweight and I would think over time that weight would inevitably reduce after rebuilds or revisions.

Different series and era I know, but the 1997 A4 Quattro Supertourer had a build weight of about 920kg, its race weight was 1040-1080kg.

[veeten]

I do believe that Adam has some info from the charts and graphs that were made involving the cars built and raced this season, and should have base weights of the challengers, as well as the amounts added on by BoP .

Adam, if you can help us...

[Adam43]

Here is how the BoP weights changed in 2023: https://tentenths.com/forum/showpost...&postcount=547

Doesn’t tell us anything about the weight without ballast, just the minimum they had to run. Doesn’t even tell us what they ran. It might be that someone couldn’t get down to that weight, but I don’t expect that is the case at all. Although if you look at the powers we know Vanwall didn’t get up to that.

Ballast will play a part. Not really in absolute performance due to the the homologation and BoP process, but it could in ease of use, drivability and tyre management. Te subtle things that people can miss, but we know are so important in endurance racing.

[joeb]

Originally Posted by Adam43

Here is how the BoP weights changed in 2023: https://tentenths.com/forum/showpost...&postcount=547

Doesn’t tell us anything about the weight without ballast, just the minimum they had to run. Doesn’t even tell us what they ran. It might be that someone couldn’t get down to that weight, but I don’t expect that is the case at all. Although if you look at the powers we know Vanwall didn’t get up to that.

Ballast will play a part. Not really in absolute performance due to the the homologation and BoP process, but it could in ease of use, drivability and tyre management. Te subtle things that people can miss, but we know are so important in endurance racing.

Thanks Adam, and you're correct that potential for ballast placement is important. This just gave me a thought.

The increased weight for hypercar was in the name of cost savings, and yet....the original form of the current Oreca P2 car cost less than the current hypercar or lmdh, and was lighter and faster? A 3:24 in 2020 was the fastest I remember at Le Mans. Other circuits probably are even more favorable for the previous tuned P2s.

[Adam43]

I suppose there is the hybrid, potential for some heavier engines, the ability for more styling without worrying about weight, and the concern that some manufacturers couldn’t build something as light as Oreca.

Basically lots and lots of flexibility.

[TF110]

Iirc, the cars are built to be able to have up to (set kg number) of ballast added? So I am assuming that that's for bop. These cars are probably built to a lot lower weight than they're running. I think a good example of this is the new 499 modificata and the specs it produces vs the wec hypercar.

[Gerard C]

I'm with you here, joeb, ballast placement is important and changes of BoP must be anticipated. Taking Toyota as an example, they had to go from 1043 to 1080 and support a 3,5% increase (thanks for the chart Adam43) a very important change. Is this kind of gap discussed before and/or during the season is a well kept secret (in the texts). It must be part of the original design of the car imo.

[J Jay]

Originally Posted by TF110

Iirc, the cars are built to be able to have up to (set kg number) of ballast added? So I am assuming that that's for bop. These cars are probably built to a lot lower weight than they're running. I think a good example of this is the new 499 modificata and the specs it produces vs the wec hypercar.

That was my understanding as well.

Any weight reduction would depend on how ballasted the heavist car is though. If a car has a dry weight of, say, 1025kg, then any reduction below that would require significant work, if not a full redesign. In tis case, the new mandated minimum weight would have to be more than this.

[Adam43]

It’s just speculation, but I would guess that the more privateer effort doesn't need much ballast to be get to the 1030kg, even if not hybrid.

[tomcug]

Light cars are possible even for privateer efforts, for example Ginetta's LMP1 was sub-800 kg without ballast. But this is completely different ruleset with much higher target weight so indeed I wouldn't expect at least some of these cars to carry much ballast to reach 1030 kg.

[Adam43]

That was my reasoning too.

It is cheaper to not, so some of them might not.

[veeten]

That's why it's better to build to the newer rules set, rather than trying to retrofit a chassis from a previous one. It's not just weight, but, as we've seen, other aspects that have changed that makes it nearly impossible to just drop something in and expect it to work, even with planning.

This is why many of those chassis engineer/ manufacturers have been working with auto manufacturers to develop and build the present prototypes we see today. This was coming, according to the individuals in charge, it just took crafting the rules that would make it happen in a reasonable amount of time.

... and here we are.

[TF110]

I think it's pretty reasonable to assume most of these cars are under 1000kg and they use ballast to make minimum weight. Plus they have to be able to carry additional ballast in the bop rules. So making your car light as you can then using the weights is probably the easiest.

[Matador]

Originally Posted by TF110

I think it's pretty reasonable to assume most of these cars are under 1000kg and they use ballast to make minimum weight. Plus they have to be able to carry additional ballast in the bop rules. So making your car light as you can then using the weights is probably the easiest.

Not so sure. Toyota had to do some significant re-engineering to do when minimum weight was reduced with LMDh convergence. of course that was ballasted, but how much ballast?

“We started the development of our car in 2018 for the regulations which have been validated in December 2018,” Vasselon told Sportscar365.
“Since then, there have been several changes. One change happened in 2020 to prepare for the convergence with LMDh, which suddenly changed the minimum weight from 1100 to 1030 kg.
“This change we are fully on board with. We accepted it because it was a condition for convergence. But we could not fully achieve this. It has hurt us in terms of weight distribution.
“We could not meet the weight distribution that was planned initially, simply because we had ballast with 1100 kg. The tires we had last year were absolutely not suited to our weight distribution.
“This is something that we have openly discussed with all shareholders. The fact that we had to change tires was a kind of no-brainer. It goes beyond performance.”
Toyota addressed its weight distribution problem by changing the dimensions of its wheels, bringing in 12.5-inch widths on the front and 14-inch widths on the rear.
That move naturally brought about new Michelin tires. The Toyotas now use the French manufacturer’s 29/71-18 size on the front and 34/71-18 on the tail end.
“It is all driven by the change of tires,” said Vasselon.
“We had to change tires just to have the correct tire when we had our weight, when we had a more rearwards weight distribution than initially planned.

[TF110]

Right, Toyota's first iteration of the GR010 was mostly built for different rules. I think that was to accommodate Aston Martin who then withdrew. I recall they did a big update on the car for 2023 which Peugeot were not too happy with.