LMP1 diesel performance adjustment

[veeten]

Funny... seems like a few folks want to put restrictions on the diesels with Audi's 1st-3rd finish at Le Mans. But I'd bet if the ACO decided to revisit the Group C regs of the 80's in conjunction with the rise of Alternate Fuels & Hybrids, the same people would blow a gasket over that.

[Lusitano]

Originally Posted by gwyllion

What should the ACO change next year to make petrol and diesel car more matched?

Nothing! If you must do something, ban petrol! DIESEL IS THE LIGHT!!!

[knighty]

Originally Posted by canam

BTW, does anyone know if my Audi diesel would actually run on the fuel that they use in the R10. My guess is that it wouldn't.

Ban the special fuels and that ought to generate a level playing field.

I'm told that the diesel used in the R10 is produced from the GTL process, (Gas To Liquid) aparrently its a verh high cetane rating about 70.....cetane in deisel is like octane to petrol......the higher the cetane number the quicker it burns.......normal pump diesel is about 45-50 cetane.......but the ACO rules do allow a max of 70 cetane.......someone also told me the R10 fuel evaporeted when it was spilt on the floor - god knows how true that is.......there is also a section on Mulsanne Mikes web site saying the fuel is derived from coal extract - now I'm lost on that one!.......but to answer your question - I reckon the R10 fuel would actually run OK in your diesel road car

[MulsanneMike]

Originally Posted by knighty

I'm told that the diesel used in the R10 is produced from the GTL process, (Gas To Liquid) aparrently its a verh high cetane rating about 70.....cetane in deisel is like octane to petrol......the higher the cetane number the quicker it burns.......normal pump diesel is about 45-50 cetane.......but the ACO rules do allow a max of 70 cetane.......someone also told me the R10 fuel evaporeted when it was spilt on the floor - god knows how true that is.......there is also a section on Mulsanne Mikes web site saying the fuel is derived from coal extract - now I'm lost on that one!.......but to answer your question - I reckon the R10 fuel would actually run OK in your diesel road car

I'll admit I know little about fuel chemistry. But its been mentioned to me from those who have witnessed it that the R10's Shell fuel evaporates in seconds when spilled. The fuel is also clear, could it be a large constituate alcohol?

[Adam43]

I liked the suggestion that the fuel was extracted from coal. I doubt this, but it would be a bit of good PR. It has been done before and is not that it is new - last time it was tried on any scale was in WW2 Germany AFAIK. During the process to acheive this it would be simple to play with the composition too.

[dj choc ice]

Originally Posted by Lusitano

Nothing! If you must do something, ban petrol! DIESEL IS THE LIGHT!!!

WHAT IN THE NAME OF ALL THAT IS HOLY DID YOU JUST SAY!!!!!,

have you ever actually been to a race with prototypes in it the noise is unbelieveably good diesel are awful they sound terrible and make no noise at all and are dull to watch i was bored to death watching the R10 on TV there was no noise and no excitment, lusitano you need youre head checking because its people like you that are ruining motorsport youre ina one man band, people want to see cars that actually sound good not a bunch of wooshy noise and diesel is not the light i would never touch a diesel car let alone pay money to see diesel racing car

[Adam43]

It is only his opinion. No need to go overboard against Lusitano for expressing it.

I can see the POV. Diesel is new in racing, it has just won its second major race (and the biggy at that). Diesel is on the way up at this moment in time.

I'm a petrol boy myself, but if we want (and this may be the question) it to be related to road cars then there is mileage in diesel.

[Danske]

Originally Posted by AdamAshmore

Diesel is new in racing...

Quick quiz. What car had the 1952 Indy 500 pole?

[Lusitano]

Originally Posted by dj choc ice

WHAT IN THE NAME OF ALL THAT IS HOLY DID YOU JUST SAY!!!!!,

have you ever actually been to a race with prototypes in it the noise is unbelieveably good diesel are awful they sound terrible and make no noise at all and are dull to watch i was bored to death watching the R10 on TV there was no noise and no excitment, lusitano you need youre head checking because its people like you that are ruining motorsport youre ina one man band, people want to see cars that actually sound good not a bunch of wooshy noise and diesel is not the light i would never touch a diesel car let alone pay money to see diesel racing car

hehehehe

Breath, breath, that's it...

If you went to Le Mans, or Sebring, then you paid to see a diesel racing car. Even if you watched it on tv,considering the tv tax (I do not know if you have it), you paid to watch a diesel racing car. :-)

[Adam43]

Originally Posted by Danske

Quick quiz. What car had the 1952 Indy 500 pole?

and one had, pre Le Mans 2006, already won a 24 hour race. However generally the point still stands and was said with the above knowledge. The point was that you can hardly say that racing and winning with a diesel is prolific.

[PascaLM]

I'm afraid that no adjustement will be undertaken by until both Audi and Peugeot reach their strategic goals.
But a lower turbo boost for diesel engines should encourage other LMP1 to continue.

[JAG]

Isn't that all people are asking for, lower turbo boost?

[Animeishdwarf]

Yes, but messing around with boost pressures can be dangerous, or cause spurrious engine wear, or waste gate problems, plus, it takes a bit of time to change boost pressure, and it's tough to check 30 something cars, or more for their boost pressure, before and after a race.

I think they'd go for something easier to change, but it'd make things more even.

[canam]

I have no knowledge about fuel issues but would you not get the same result (as lowering boost--which I believe is already monitored) by forcing all diesels to run on pump fuel where the cetane levels are lower (say within 50-55).

Le Mans petrol had an octane rating of 101 which only marginally higher (3-4%) than what you get at your gas station. According to other contributors, the cetane level of the Audi's fuel was 40% higher. (I have also heard that the cost of 'buying' the fuel is more than 20 times the pump level).

[1200Datto27]

I can get 100 octane pump fuel here (Australia) or 100 octane race fuel, the race fuel will cost me around 6 times as much as the pump fuel, but will also generate 20% more power. This is because there is more to fuel than just the octane rating, you have to look at things like oxygen levels, specific gravity, calorific values, etc. and this is what makes the difference in performance and cost. I'm pretty sure that the Pescorelos would not have been running pump fuels.

[canam]

All the petrol-engined cars were running fuel that is supplied by the circuit at Le Mans and has a certain stable and specific composition and runs at 101.

The only car, to my knowledge, that ran any different fuel from that supplied directly by the ACO was the two Audis. Shell made it specifically for Audi and supplied it directly to the team.

[Gil Abobeleira]

Originally Posted by pirenzo

But the diesel clearly doesn't make a better race car. It's allowed 1.5 litres more capacity than it's petrol counterparts. That's not equivalency, it's a gift...

That's as stupid as imposing a engine limit of 4 littres to turbo (or kompressor) engines VS 6 littres to atmospheric engines. If a 4 littre turbo engine is better than a atmo one, why does it carry smaller restrictors (reverse anology. A normal diesel engine cannot face a gasoline engine with the same displacement and, likewise, a turbo engine is better than an atmo one with the same displacement).

BTW: if we really want to compare very different cars and, even pegging back laptimes, there is this "very strange" thing with imposing a consumption formula, say 40 littres for 1000km and no restrictors or turbo-boost regulators.... To clever, tight guys? The last thing I heard, it was called Group C, whre we could find a boxer 6 vs V12 7 littre vs V8 Turbo 5 littre vs V8 Turbo 3.6 etc.... And nobody was *****ing with restrictors, power advantages...

[dj choc ice]

the only way i can think of balancing out the economical advantage of the petrol and diesel cars is to give the diesel cars a smaller restrictor than everyone else and to give the petrol cars a slight performance advantage to make up for not having as good fuel consumption or giving the diesel audi's a smaller petrol tank the A.C.O have said that everyone in LMP1 should at least have a fair chance of winning overall but the A.C.O have put the diesel cars at a huge advantage with much bigger displacement for turbo cars and also a bigger restrictor and the same size fuel tank is obviously even on paper going to put audi at a large advantage and the A.C.O are going to appreciate the fact that this decision is slowly going to destroy sportscar racing and lemans and im sorry but i cant bear to see this happen since LMP's are just the business to me and its one of the reasons i was so upset to see the audi R8 going into retirement sure the R8 was not very loud but it was super loud compared to the R10 audi's i thought when they announced the R10 i thought yes the new audi R10 because i think im the only one but i love the looks of the audi R10 it just looks amazing but the R8 was a nicer looking car and i thought the R10 was going to have a 3.8 or 4.0 turbo V8 not this clattery diesel crap, i hate diesel a lot with a passion but my respect for audi for making the diesel engine as a race car application is massive audi have indeed broken the rules bringing the diesel technology into motorsport but its something that i would rather not see ever again

[Alex Hodgkinson]

If any rule changes happen I hope that they act to increase the performance of the petrol-powered cars rather than to restrict that of the diesel cars, for the simple reason that there's already too much "fake" racing happening in the world.

[Animeishdwarf]

Originally Posted by canam

All the petrol-engined cars were running fuel that is supplied by the circuit at Le Mans and has a certain stable and specific composition and runs at 101.

The only car, to my knowledge, that ran any different fuel from that supplied directly by the ACO was the two Audis. Shell made it specifically for Audi and supplied it directly to the team.

In accordance to ACO rules, all cars must run only the fuel provided by Le Mans and the ACO. If not, you're disqualified. Audi's got special permission for it, and the ACO granted it (obviously) but yeah, they mandate octance rating and sulfur levels (diesel) so everything is fair as possible.

But, I'm sure most of you knew that.

It might work, but it might also be a pain in the arse, as you in Europe say.

[gwyllion]

Why is it so strange Audi got some special fuel from Shell? They were the only ones using diesel. I saw nobody complaining about the bio ethanol that Nasamax ran on I am sure Audi and Peugeot will use the same fuel next year.

The specs of the 2 fuels available are online on lemans.org:

• Shell V-Power Diesel "LM24" : Technical Data Sheet
• Shell V-Power "LM24" : Technical Data Sheet

As you can see, both fuels are within the spec defined by ACO.

• V-Power "LM24": octane = 101,7 (ACO mandates min 101 and max 102)
• V-Power Diesel "LM24": cetane = 62 (ACO mandates min 51 and max 70)

BTW cetane 62 is a lot less than the 70 someone claimed.

[The Badger]

I feel that it was the decision of Audi to go the diesel route , so they should have the same refueling valve as everybody else . They will have a big enough performance break with diesel anyway .

[gwyllion]

ACO will react to diesel advantages. Diesel fuel has 11% more energy than petrol fuel. The tank size will be changed so that cars will have the same amount of energy in the tank for both fuel types. A bit similar like Nasamax (bioethanol has less energy than petrol).

Der Streit entzündet sich vor allem am Tankvolumen und an den Restriktorgrößen. Diesel und Benziner fahren mit 90-Liter-Tanks. Dieselkraftstoff enthält bei gleichem Volumen aber elf Prozent mehr Energie als Benzin.
...
Rennleiter Daniel Poissenot kündigt indessen an, der ACO werde reagieren. 2007 wird die Energiemenge in den Tanks von Dieseln und Benzinern gleich sein.

source: http://www.auto-motor-und-sport.de/s...ieg.116167.htm

So we could have different tank sizes:

• diesel: 80 liter
• petrol: 90 liter
• bioethanol: 100 liter

[Adam43]

Originally Posted by gwyllion

Diesel fuel has 11% more energy than petrol fuel.

That is certainly true. Although interestingly Diesel has less energy per kg, except that it is more dense.

Diesel is approximately .89kg/l and petrol .74kg/l (depending!)
So 90kg of petrol is 5kg less than 80kg of diesel. When I set off with my calculator I thought it might be significant, but that is only a 2.5kg average over a stint in a 925kg car.

[gwyllion]

ACO has made the decision to reduce the tank size for diesel powered car. See this thread.

I still expect changes in restrictor size to overcome the power advantage of diesel engines.