WEC (World Endurance Championship) 2014

[machin]

Of course it's silly to think that you can just get 20% more efficiency without any penalty by changing maps, since if you could do that, you may as well do it from day 1 and not just at le mans.

Exactly: you work out what the best* BSFC you can achieve is (where "best" must account for things like reliability and whether you can sustain that BSFC throughout the rev range), and that is what you declare to the FIA... but you can never improve efficiency (by further leaning out the mix, for example) because that would improve BSFC and the FIA is monitoring your instantaneous BSFC to make sure you don't improve on the declared value.....

It is worth remembering that efficiency is inversely proportional to BSFC (a lower BSFC = more efficient); anything anybody can come up with to improve efficiency will improve BSFC, and therefore breach the rules...

More Power for the same fuel = better BSFC = NOT ALLOWED.
The same Power for less fuel = better BSFC = NOT ALLOWED.
A little less power for a lot less fuel = better BSFC = NOT ALLOWED.

Of course, because there is only one Diesel competitor, there is no incentive for Audi to chase BSFC at all since their engine will automatically be balanced against the best petrol engine in the EoT process... whether it is good or bad... and that in turn means they must rely on a better Chassis, better aerodynamics, a bigger Hybrid system, or better drivers, or better reliability to beat the best Petrol... we know the Audi has a smaller Hybrid system than Porsche or Toyota, so to win they must have better Chassis, better aerodynamics, better drivers, or better reliability... or dare I say it... better luck...??!!

[andylaurence]

Exactly: you work out what the best* BSFC you can achieve is (where "best" must account for things like reliability and whether you can sustain that BSFC throughout the rev range), and that is what you declare to the FIA...

This is key. BSFC will have a peak value. By specifying the lowest value you can achieve, then you can ensure that BSFC is available at all times and not just at peak.

[machin]

Yeah, and actually this is one area of the rules that I don't like since it actually promotes inefficiency....

A typical engine might have a power curve like this, with iso lines showing BSFC:-



In which it only achieves peak BSFC over a small operating range... clearly that is no good in the current rules since that means you can only operate at the declared BSFC for a small time if you declare the best figure possible (200g/bhp.hour in this image)... if you were Audi it would be better to de-tune your engine in the good BSFC areas and declare a worse BSFC to ensure that your engine achieves the declared BSFC over a much larger operating range (e.g. by running slightly richer in these areas of the power curve), and then rely on the EoT process to ensure you have the same power and range as the best Petrol engine whilst running at a worse BSFC than you could actually achieve:-



Porsche and Toyota probably can't do this quite so easily since they are competing against eachother (The FIA chooses the best (lowest) declared BSFC from both of these competitors and uses this for the EoT process to balance petrol and diesel). I suspect however, that both Porsche and Toyota are using the above strategy to some degree... and that means that none of the competitors are likely to be running with engines that are as efficient as they could be if BSFC wasn't constantly monitored....

[machin]

So, the question is, how do you stop this practice of running engines at lower efficiency?

Well, how about this: you scrap the BSFC monitoring entirely and instead use the BSFC of commercially available petrol and Diesel engines (those used by you and me to drive to work) for the EoT process...

That means a race team will get an advantage if their race engine uses technologies which allow it to achieve a better BSFC than the best commercially available engine of the same fuel type, and will lose out if they use an engine with a poorer BSFC than the commercially available engines.... and that would promote trying to improve BSFC by developing new technologies for the race engines. Eventually these technologies would find their way into the commercial engines used for the EoT and the race teams would have to develop new technologies to continue to get a benefit on the race track, and this would eventually find it's way into the commercial engines used for EoT... etc etc....

You could ask the highest placed Petrol engine team from the previous season to nominate one commercially available DIESEL engine, and the highest placed Diesel team to nominate one commercially available PETROL engine for use in the FIA's EoT process....

[WhiteBlue]

Interesting thought.

[stefan_]

Here is the entry list for the next race - 6 Hours of Spa



And another shot of the new Rebellion R-One

[Holm86]

[Cold Fussion]

Yeah, and actually this is one area of the rules that I don't like since it actually promotes inefficiency....

A typical engine might have a power curve like this, with iso lines showing BSFC:-

http://i90.photobucket.com/albums/k248/ ... 7fa1d9.jpg

In which it only achieves peak BSFC over a small operating range... clearly that is no good in the current rules since that means you can only operate at the declared BSFC for a small time if you declare the best figure possible (200g/bhp.hour in this image)... if you were Audi it would be better to de-tune your engine in the good BSFC areas and declare a worse BSFC to ensure that your engine achieves the declared BSFC over a much larger operating range (e.g. by running slightly richer in these areas of the power curve), and then rely on the EoT process to ensure you have the same power and range as the best Petrol engine whilst running at a worse BSFC than you could actually achieve:-

http://i90.photobucket.com/albums/k248/ ... 5c9fb6.jpg

Porsche and Toyota probably can't do this quite so easily since they are competing against eachother (The FIA chooses the best (lowest) declared BSFC from both of these competitors and uses this for the EoT process to balance petrol and diesel). I suspect however, that both Porsche and Toyota are using the above strategy to some degree... and that means that none of the competitors are likely to be running with engines that are as efficient as they could be if BSFC wasn't constantly monitored....

Don't they also have a fuel flow limit though? So detuning your engine for worse BSFC would mean you're trading power you could have, in the hope for a better EoT balancing? I would think Porsche could play this game far more than Toyota could, because their engine is surely more efficient than the Toyota engine.

[TzeiTzei]

Sad to see LMP2 is down to only 5 cars. I'm hopeful of a better future for that class with the new Ligier, Strakka Dome, Oreca and HPD attracting more teams.

[machin]

Don't they also have a fuel flow limit though? So detuning your engine for worse BSFC would mean you're trading power you could have, in the hope for a better EoT balancing?

No they don't lose out, because the fuel allocations have been made by the FIA AFTER the manufacturers have declared their BSFC, as per process below:-

1, The manufacturer's declared what they can achieve from the fuel in terms of BSFC.
2, The best Petrol and the best Diesel BSFC is selected by the FIA.
3, The FIA provide a per lap fuel allotment, a maximum instantaneous fuel flow rate and a total fuel capacity to ensure that the top Petrol and the top Diesel have the same average power/kinetic energy per lap (inclusive of hybrid system) and the same amount of kinetic energy between refuels (exclusive of hybrid system) if they are running at the declared BSFC.
4, If any manufacturer beats the BSFC values from step 2 during the race they will be penalised.

Nothing stops you from:-

A, Running at a worse BSFC; but then you're just wasting fuel (losing out on kinetic energy), or
B, Using less fuel (but using it at the BSFC limit).

This last point is cruicial... you could use less fuel to try and eek out another lap... but of course that will mean you will go slower* because you won't be using the fuel at the maximum per lap allocation...

* unless of course your chassis, aerodynamics, tyres or drivers are better than your opponents, in which case you might be faster even though you're using less fuel...

[Cold Fussion]

That clears it up, didn't realise the maximum fuel flow rate were decided after the declared BSFC values. Seems like it is completely counter productive system to the goal of increasing fuel efficiency.

[WhiteBlue]

That clears it up, didn't realise the maximum fuel flow rate were decided after the declared BSFC values. Seems like it is completely counter productive system to the goal of increasing fuel efficiency.

Not really. The BSFC is updated regularly and optional whenever a breakthrough happens.

[machin]

Not really. The BSFC is updated regularly and optional whenever a breakthrough happens.

But there is no incentive for Audi (who don't have a diesel competitor) to chase BSFC since they'll be EoT'd up (or down) to the same energy allowances as the best Petrol anyway...

In fairness, the FIA/ACO have made it clear that they want the emphasis of developement to go into the Hybrid systems (which is why the Hybrid systems are not included in the total fuel capacity balancing equation) and not on developing the engines, hence the 2014 EoT process.

[Artur Craft]

Does anybody have CAD models of the LMP1s to test on CFD?

Yeah, I know. I'm asking too much but maybe, luckily enough, somebody might have had the effort

[PorscheLMp1Fan]

Think Perrin have released the files for their car, I imagine you'll be able to download it from their website. Not sure if it's the whole car though or just bits and pieces.