[WEC] WEC 2021 season

[Simmi]

Almost seems like grandfathering a car and trying to cheaply muscle in on a new class, against teams putting millions into developing machinery to the regulations, isn't the best idea.

[canaglia]

Originally Posted by Adam43

They could just reduce the maximum energy so Alpine’s tank is adequate.

Although I’m not keen on shorter stints.

I honestly can't figure out yet what that max MJ a stint value means...
because if for alpine that energy value indicates the amount of energy given by the fuel combustion well... it apparently doesn't make any sense...
Taking for granted that alpine has a 75L fuel tank and that tank is completely filled at each refuel, we should have 920MJ/75L = 12,267MJ/L

12MJ/L is almost the energetic density of liquid ammonia... the only fuel with similiar low energetic density is methanol (15MJ/L).
Petrol energetic density is more than double.

[Adam43]

I think that it isn’t the chemical energy that is in fuel, but rather then energy you actual use. A combustion engine is not 100% efficient so that explains the difference, 50% is really good efficiency from a ICE. I believe the energy used is measured on the car. This is why fuel tank size isn’t the actual rule.

Edit: the measured by Torquemeters is mentioned the bulletin about the pitstop lengths:
http://fiawec.alkamelsystems.com/Res...d_28042021.pdf

[canaglia]

honestly that looks so useless and stupidly overcomplicated

[Adam43]

Possibly. But ultimately Alpine’s tank just isn’t big enough.

[canaglia]

Originally Posted by Adam43

Possibly. But ultimately Alpine’s tank just isn’t big enough.

Ok but aside the calculation of refuelling time, that value hasn't an impact at all... toyota was allowed to overall/combined 700hp and had a 52m/25laps only because of 90L fuel tank, it's not drivers were saving fuel/energy lifting off or else.

[Adam43]

Not really sure what your point it. The value does effect the tank size you need.

Alpine are allowed to do such stint lengths, if it had a tank that was more suited to the rules. The rule isn’t that the tank size, but the energy used in a stint. Alpine aren’t using what they are allowed to because they haven’t got a bit enough tank. Toyota fitted a 90l tank because that enabled them to do the stint length allowed in the rules.

Not sure on the point about life and coast. That’s good thing? I’m up for a bit of racing with less lift and coast? Even if it has been in Sportscar racing for a long long time. It could still be part of the racing depending on its effectiveness at the track.

[Mike E]

Originally Posted by Adam43

I’m up for a bit of racing with less lift and coast? Even if it has been in Sportscar racing for a long long time. It could still be part of the racing depending on its effectiveness at the track.

Lift and coast is very good as a tactic but less interesting as a strategy.

[Adam43]

Nice way of putting it. I'm not up for it if it is the only way to drive the cars, but if circumstances suggest it is an opportunity then good stuff.

[canaglia]

Originally Posted by Adam43

Not really sure what your point it. The value does effect the tank size you need.

Alpine are allowed to do such stint lengths, if it had a tank that was more suited to the rules. The rule isn’t that the tank size, but the energy used in a stint. Alpine aren’t using what they are allowed to because they haven’t got a bit enough tank. Toyota fitted a 90l tank because that enabled them to do the stint length allowed in the rules.

Not sure on the point about life and coast. That’s good thing? I’m up for a bit of racing with less lift and coast? Even if it has been in Sportscar racing for a long long time. It could still be part of the racing depending on its effectiveness at the track.

I explain better, during 2014-2020 lmp1-h ruleset; toyota, porsche and in part also turbodiesel audi as well had to manage fuel consumaption because of lower fuel flow rate and smaller fuel tank, lift and coast was basically mandatory to don't run out of fuel or to don't have to refuel more often than competitors. Now with HYP ruleset this doesn't happen anymore, toyota was allowed to run at combined/overall 700hp during the race, and because of this their stint lenght was given exclusively by the larger fuel tank size (from <50L a stint of last year to 90L).
If fuel tank was smaller they would had shorter stints, if was larger they would had longer stint, so at a bop given X overall/combined power is fuel tank size that decides the stint lenght not the bop overall MJ/stint.
That MJ value has no impact because is a consequence, not the cause.
Look that from alpine point of view, they have a 75L fuel tank and apparently can't do anything about to get a larger one, so at that max MJ given value they could be using more power to compensate and to achieve or reach that overalll max MJ "usable" per stint, but actually they can't because bop gave them 600hp as max power anyhow. So... if a team knows from the very beginning how powerful can their car be and how long they can stay on track because of consumes and fuel tank size, what's the deal of this MJ value? it basically has no importance (but refuel time calculation)

[Adam43]

Yes, the rules define the power of the engine and the energy used in a stint. The rules do not define the fuel tank size.

The energy used in a stint is directly linked to the length of the stint. In the old days the rules defined the tank sizes, now different cars are given different energy limits. Power has been limited for a long time now.

To try and explain using something like your last sentence. So... if a team knows from the very beginning how powerful their car can be and how much energy they can use in a stint because of the rules, they can work out what size tank they need. The MJ value is hugely important in this.

If the ACO doubled everyone’s energy per stint then people could, in theory, just fit bigger tanks. If it could physically fit! Alpine are asking for a lower energy limit so that their current tank size is suitable. Toyota would then use less of their tank, or could fit a smaller one if they could be bothered.

[canaglia]

Originally Posted by Adam43

To try and explain using something like your last sentence. So... if a team knows from the very beginning how powerful their car can be and how much energy they can use in a stint because of the rules, they can work out what size tank they need. The MJ value is hugely important in this.

This could be valid ONLY if manufacturers knew the targeted overall MJ value or a range of that during the design phase of the engine, or however before the final homologation of the car since fuel tank size can't be changed once homologated.
Manufacturers knew for sure the targeted power of HYP class (670hp), so was natural for them to produce a suitable fuel tank according to consumes of the engine at that power.
Guess Jim could clarify this doubt.

[Adam43]

Originally Posted by canaglia

Manufacturers knew for sure the targeted power of HYP class (670hp), so was natural for them to produce a suitable fuel tank according to consumes of the engine at that power.

Yep. So you’ll make sure you have a tank suitable for 964MJ or 920MJ depending on whether you have a hybrid or not! Or maybe a bit bigger for some flexibility?

This could be valid ONLY if manufacturers knew the targeted overall MJ value or a range of that during the design phase of the engine,

That’s OK then as they do!

Although the idea with these regs is it this allows a variety of engines. So it is more likely be that you can take an engine and, knowing its (and the car’s) efficiently, know what fuel tank you need.

or however before the final homologation of the car since fuel tank size can't be changed once homologated.

Can fuel tank size not be changed due to homologation? I’d be surprised.

Not sure it’s a problem anyway as anyone designing their car are good as they know.

Guess Jim could clarify this doubt.

I’m going to guess this won’t be a problem for anyone else!

It’s only a problem for Alpine because they are using an old car that they didn’t design and can’t fit in a bigger tank.

Maybe we’re saying similar things?

[canaglia]

As far I know, once hypercar is homologated the car can't use different parts, alpine R13 is not a hypercar so they could be allowed to use different parts mainly because of a grandfathered car bop necessities.
Here again Jim could drop us some wisdom about homologation frozen specs limits.

About the engine, well that "ONLY" is a really big condition, because if toyota, pipo moteurs, peugeot and ferrari knew from the very beginning they had to stick to that MJ's (or a range of that) as a sport regs parameter, then they would had designed the engine and fuel tank according to that, to better explain:
knowing my engine's fuel consumption, how much fuel do I need to get a range of 500-520KW keeping overall performances to not exceed that overall MJ value?
The answer of this question is the tank fuel size.
But if manufacturers didn't know the targeted overall MJ value that ACO decided and will decide for next races during engine design phase, well in that case for manufacturers was just about to get a reasonable large fuel tank to stay safe... but here again the same question:
given for granted that alpine had shorter stint because of smaller fuel tank, was toyota able to stay on track 52 minutes a stint because otherwise they would had exceeded the overall MJ limit or because 52 minutes is their max autonomy given by a 90L fuel tank?
If the truth is in the second option, well, overall MJ value has no impact.

That's why I'm curious to see if 007 will be able to have same stint lenght with a 20L larger fuel tank, but only ICE powered.

[Adam43]

Are you suggesting that Toyota don’t get near the 964MJ in a stint? What makes you think this?

Unless you’ve got a car designed to old rules and no flexibility to increase the fuel tank I don’t think anyone is going to have a problem here.

[canaglia]

these are just my guesses, but at the end that's where the question lies:

A: toyota refueled each 52m with still some fuel on tank, potentially able to run longer but forced to don't go any longer because of MJ a stint limit?

or

B: toyota refueld each 52m because it's max autonomy with 90L of fuel?

if the answer is B, as said before the MJ value is irrilevant because stint lenght is given only by fuel tank size and max power is given by bop regardless.

[Adam43]

But the answer is A! No one is suggesting anywhere that Toyota have a tank that is too small. It is unlikely any team that designs a car to the regs will do that.

But ultimately I agree if any team decides to make a fuel tank smaller than needed for their energy allocation then this will limit the stint length!

[canaglia]

Originally Posted by Adam43

But the answer is A! No one is suggesting anywhere that Toyota have a tank that is too small. It is unlikely any team that designs a car to the regs will do that.

But ultimately I agree if any team decides to make a fuel tank smaller than needed for their energy allocation then this will limit the stint length!

I'm afraid only toyota engineers and ACO officials know the truth, that's why a direct comparison with a similiar car like 007 can help a lot.

[Adam43]

Do you actually think it is likely that Toyota can’t use all the allowed energy in the stint because they fitted a tank that was too small? I know what you say is a technical possibility, but...

No, it’s A!

Maybe Toyota don’t have enough travel on their throttle and can’t use all the power of the engine. Maybe they sequential gearbox stops at fifth gear. Only they know!

BTW. I didn’t know the fuel regs going into Spa. So I read up on them, got the actual rules and digested them. I even spoke to someone from one of the teams. It is only suggested that Alpine have a tank too small because their car was designed to the old rules. Zero suggestion that it is anything other than the MJ energy limit that defines the maximum stint for others.

I see you also asked another team by asking Napolis on this very forum. Although you did tell him he didn’t understand the situation.

Originally Posted by canaglia

would be interesting to see how or if things will change with the 007 debut, according the specs that car has a 110L fuel tank, even if it has to be considered that unlike toyota the 500-520kw power will come only from ICE, so it should consume more anyhow

Originally Posted by Napolis

Our fuel system will give us both range and re-fueling speed we need. Total non issue.

My bold.

Originally Posted by canaglia

It's not about refueling speed, it's about how long a 007 stint could be compared to the alpine because of larger fuel tank.

Originally Posted by Napolis

Everyone will have the same range period.
If you need larger tanks you can have them but as they take longer to fill it is about refueling times. Our refueling times will be fine.

Here Napolis confirms total non-issue. He suggests that they were more worried about refuelling times than stint lengths. And even this isn’t an issue.

It isn’t for Toyota either. They have actually slowed down their refuelling speed from last year and can, as we saw (!), easily fill in the 35s time.

[canaglia]

As said, nobody here is in the position to be 100% sure about opt A or opt B, nobody has enough data to go beyond hypothesis.
Another thing to consider is a quick analysis about consumes. In 2018-2019 WEC there was no success handicap, TS050 had a 2.4L V6 pushing in the range of 600hp and with <50L of fuel a stint had an autonomy of about 40 minutes, achieved only through extensive lift and coast at each lap.
This year GR010 has a 3.5L that pushes 700hp for most of the laptime and revs high up to >8000rpm according to hud telemetry, not to consider that toyota drivers are now pushing all the time. I can't remember in the past of about 1hour stints long, not even when petrol lmp1 cars had 90L fuel tank before 2011.
I know that toyota engine has f1-like % of thermal efficiency, but 52min in full attack is a lot of time, that's why I think that 52m is the autonomy limit more than anything related to MJ limits.
A direct comparison with 007 can be helpful because if both toyota and 007 have a comparable MJ value at exact same 500-520KW max power, it would mean that both cars should virtually have the same stint lenght, but if 007 will be able to run longer than toyota 52minutes, it will be only because of those 20 extra liters.

[Adam43]

This is brilliant! You can’t be 100% of anything. So that means any theory is valid!

But even a hypothesis needs to be based on something! By far the most likely conclusion is that Toyota have a big enough tank to utilize the energy allowed. If they don’t then they have dropped the ball. And from my understanding they have not. In fact, other than yourself, no one considers it to be anything but.

BTW, when it comes to it you also need to bear in mind that the length of a stint might not be identical for each car. Different cars might be different and different drivers might be able to use the energy and go further. Although we don’t expect too much lift and coast it seems. Further hybrid and non-hybrid have different stint energy allocations.

Anyway. Glickenhaus might go further because it has alien technology from the planet Magrathea. Now that’s a hypothesis. And you can’t say I’m wrong.

[canaglia]

Originally Posted by Adam43

Anyway. Glickenhaus might go further because it has alien technology from the planet Magrathea. Now that’s a hypothesis. And you can’t say I’m wrong.

I can't say you're wrong, but I could say my hypothesis are at least argumented on technical data and observable findings.

[Adam43]

Barely. There is nothing to suggest that Toyota have decided to have a smaller tank. And the most logical situation is that Toyota have given themselves the flexibility. And, I understand, that they have a tank that is big enough. As do Glickenhaus.

But you are right anything is possible.

[tux]

What if they just drove really fast until the end of the race and somebody wins?

[canaglia]

Originally Posted by Adam43

There is nothing to suggest that Toyota have decided to have a smaller tank.

Infact I never wrote or intended toyota has a smaller tank, it's just the opposite considering no lmp1-like car before had stints about 1h long.
If you didn't get yet, I have doubts about the impact of that MJ value on car performances and stint lenght, given precisely mainly by the fuel tank size than else IMHO.
The toyota-007 comparison I'm waiting for portimao is all that matters to clear doubts about this. Unless others will be added...