WEC (World Endurance Championship) 2014

[Callum]

So, both Audi's had front impacts that caused their retirement from the race.

During the race we were told that both tubs have been fatally damaged. In my opinion both impacts were decent, but not heavy, or large. (arguably the second was heavier). I would have expected the crash structure and suspension to be damaged - but BOTH tubs?

Does this show that the tub has a weakness? Maybe pick-up points are punching through? Does anyone know anything else?

[WhiteBlue]

.. Maybe pick-up points are punching through? Does anyone know anything else?

That was the issue reported in the coverage for the no. 1 Audi. The second was simply beached with both front wheels broken off, so Treluyer had to abandon it. I have not heard that it also had the chassis damaged.

[machin]

In my view there is still balance of performance although they now give it a different name. If they wanted to make it a fair contest they would simply give diesel and petrol the same amount of fuel energy.

It is absolutely a balance of performance between the best diesel engine and the best petrol engine, and I tend to agree with you that I'm not sure I really "like" balancing the performance of the two fuels just to make the different manufacturer's happy.

Personally I like my engineering to answer a specific question, and at the moment the EoT process means that there is no specific "question" asked of the best petrol and the best diesel; they are simply balanced against eachother performance wise.

There are several "questions" that I think would be interesting:-

1, Who can create the fastest car given the same calorific content of fuel used per lap (essentially what you suggest above). Would almost certainly favour the Diesels.

2, Who can create the fastest car whilst being limited to the same amount of tail-pipe greenhouse gas emissions per lap. The second table on this link would tend to suggest that Diesels would win this one too... with the petrols only getting 11% more litres of fuel than the diesels (2614g of CO2 per litre of Diesel vs. 2328g per litre of petrol. http://www.biomassenergycentre.org.uk/p ... ema=PORTAL

3, Who can create the fastest car whilst being limited to the same amount of total-life-cycle greenhouse emissions per lap, i.e. the refining and distribution emissions of each fuel would also be taken into account. Interestingly, based on the same table on the link above this would suggest the fuel allowance between the diesels and the Petrols would be very similar to what we have now with the petrols getting 20% more litres of fuel than the diesels (3128 g of CO2 per litre of Diesel vs 2600g per litre for Petrol).

The good thing about question 3 is that it would allow pure electric cars to answer the same question...

To make it fairer they should also mandate a minimum weight for the chassis and then the weight of the engine/fuel/hybrid system should be on top of the chassis weight; that way the respective weight advantages of each different power unit would be taken into account as well...

[WhiteBlue]

It would be a good idea to simply use the primary energy equivalent. So if you invest more energy into processing you would be further penalized.

Electricity in Germany btw. is getting more efficient yoy. The primary energy factor is already going down as a consequence of 35% renewables in the mix.

[WhiteBlue]

Nobody can stop a manufacturer to post lower power output than actually achieved. If they go for a low weigh strategy they can simply compensate by running the engine with lower than maximum power and running more laps than they would normally do. This strategy would also help reliability. So we cannot know at all if anybody has been sandbagging in the procedure up to the last EoT decision.

I wouldn't call that sand-bagging. That is called running the engine at its "optimum" conditions (where "optimum" means balancing power output, with fuel economy, with reliability).

Because there is only one competitor in the Diesel class then nothing stops Audi from running its engine exactly at the output level it wants and the FIA will balance it against the best petrol. But Audi can't then simply "turn up the wick" on their engine because then they'll break the kW/kg.hour figure that has been agreed with the FIA (sadly, undeclared to the public), which is monitored in real-time during the races by the FIA using the flow meter and torque meter. Since the kW/kg.hour figure is locked in until after Le Mans there is no benefit in sandbagging in any race.

It is slightly different in the petrol class where there is more than one competitor. There are two options for the petrol competitors; they club together and declare the same kW/kg.hour figure to the FIA and then they will both have the same Kinetic Energy available per lap in which to try and beat the Diesels... however the better option is simply to work your socks off and try and achieve the best kW/kg.hour figure you can, then (if you are the best petrol) you will only have one competitor on equal footing (the best Diesel), and hopefully you'll have more Kinetic energy available per lap than all your petrol competitors. Again, there is no allowance for "sandbagging" because the kW/kg.hour is locked by the FIA until after Le Mans and it is monitored in real-time by the FIA during the races using the fuel meter and torque meter carried by each LMP1-H car. If it turns out you're not the best petrol then you need to work hard to get your engine up to the same kW/kg.hour figure as the class leading petrol.

Basically the FIA did this because they didn't want to favour Diesel over Petrol (or vice versa), but also they didn't want to penalise the aerodynamic and chassis departments of the respective manufacturers just because their engine department have done a good job. i.e. in order to beat the class needing car from the other fuel category you can have better aero, better chassis, better drivers, better reliability.

I think it is a very good process except for one thing: since there is only one Diesel competitor there is absolutely no need for Audi to develop their engine; the FIA will simply balance them up to the same Kinetic Energy output as the best Petrol... and that seems a bit unfair...

I do not agree with you totally. Both the diesels and the petrol manufacturers can sandbag and post less power to the FiA than they can ultimately generate. If we assume that all parties would post between 80 and 95% of the power they can generate that would be a realistic assumption. A manufacturer who is more fuel efficient would likely do more sandbagging than one who is less fuel efficient and take a higher number of laps without refuelling as a competitive advantage instead. Or are they adjusting the amount of refuelling also in this exercise of EoT?

[machin]

It would be a good idea to simply use the primary energy equivalent.

That depends on what question you prefer to pose to the manufacturers... I would suggest neither is better, they're just different. Personally I prefer total life-cycle emissions, but its only my preference. I like it because it is relevant to "the real world" (depending on your view of global warming of course!)

[Tommy Cookers]

@ machin

tailpipe greenhouse gas emissions should include water vapour from combustion of the Hydrogen content of the fuel (significant)
not just CO2 as your source seems to assume

we aren't often told that 95% of the greenhouse effect is due to water vapour

[machin]

Or are they adjusting the amount of refuelling also in this exercise of EoT?

Yes; fuel allowance per lap, specific fuel consumption (kW/kg.hour), total fuel capacity and refuelling rates are all part of the EoT process....

[machin]

@ machin

tailpipe greenhouse gas emissions should include water vapour from combustion of the Hydrogen content of the fuel (significant) not just CO2 as your source seems to assume

I can't see anything that mentions water vapour on that link... Can you post a better source which definitely does include it?

[Tommy Cookers]

nobody mentions it ever
but it's the same order of magnitude as CO2
it would have some effect on the petrol vs diesel factor
also relevant to Hydrogen fuel

[machin]

it would have some effect on the petrol vs diesel factor

Which way, and by what sort of percentage do you think?

[hollus]

Re water vapor: [off-topic alert!]
That's because water vapor condenses and precipitates quickly. How long is it going to stay in the atmosphere, a few days? A few weeks? So its lifetime effect is very limited. It goes to rise the sea level in the end, not to heat the atmosphere much.

[chip engineer]

@ machin

tailpipe greenhouse gas emissions should include water vapour from combustion of the Hydrogen content of the fuel (significant)
not just CO2 as your source seems to assume

we aren't often told that 95% of the greenhouse effect is due to water vapour

But the water vapor emitted has no long term effect. Unless it is emitted at very high altitude, the water condenses into rain or snow within a few days.

[Tommy Cookers]

IMO
long term effect is just a way of saying that enhanced CO2 levels decay much more slowly than ehnanced water vapour levels

at any time regardless of its source and its persistence there's about 80 times as much water vapour as CO2 in the atmosphere
(tailpipe water vapour is no more or less persistent than the above mostly natural water vapour)
and at any time water vapour produces about 25 times as much greenhouse effect
to me that's simply about a third as 'greenhousey' as CO2
aggregate behaviour, whether of many H2O or many CO2 molecules, both with its range of histories and futures


yes, I was wrong if suggesting that it made much difference to the petrol'/diesel issue (it would with other fuels)

the thread had turned to artificialities and anomalies within the rules, I think I was in-theme with that

[WhiteBlue]

Or are they adjusting the amount of refuelling also in this exercise of EoT?

Yes; fuel allowance per lap, specific fuel consumption (kW/kg.hour), total fuel capacity and refuelling rates are all part of the EoT process....

Not according to the latest technical rule set in WEC. According to what I have saved on my hard drive all competitors are going to have the same refuelling capacity in litres. Obviously petrol litre and diesel litre allowance are different but within fuel class they are the same.