Audi R10-Peugeot 908 real numbers

[hcl123]

[quote=Dario911]I think the Porsche LMP2 is favoured by rules (in ALMS) at the same way Audi and Peugeot LMP1 are favoured in LMES and Le Mans in confront of the petrol LMP1.

Name one rule or caracteristic where Audi or Peugeot are favored in LMS... just a single little one !?

[Spyderman]

Erm...37,5% larger engine displacement for the P1 diesels in relation to the petrol engines comes to mind. (this single tiny little advantage is not only referent to the LMS)

[Dario911]

First and very important caratheristic: air restrictors.
Diesel cars' got much power in confront of the petrol cars. Pescarolo claims for his P1 quite 640 hp (with the A.C.O. air restrictors).
Audi and Peugeot claim 650-700 hp, but the real output power is estimated in 720-740 hp for both cars. Isn't this an advantage for the diesel P1?
Or would you say "no"!?
If you consider the lower fuel consumption and the tank capacity, and the game is over.
Probably this year there will be more balancing, thanks to the new air restrictors for P1 petrol cars and new tank capacity.
Ask to Pescarolo what does he think about the balancing between petrol and diesel P1s!

[gwyllion]

Originally Posted by hcl123

Well was some time ago i've read the rules:

900Kg is the minimal weight for P1 cars in LMS not ALMS, but only for this year 2008 (forward ?), and only for petrol engines i believe.

P2 cars in LMS shoud have 850Kg in 2008, Super P2 cars in ALMS still have 775Kg minimal weight.

And 925Kg, i believe is still the minimal weight for petrol P1 cars in the ALMS

The 995Kg appears when during more than half the season of 2006 when Audi won every race except 1, they IMSA administratively during the season, decised to penalize the diesels P1 with an extra ~70Kg of ballast( if i,m not mistaken), which Audi responded with the treat of abandoning the championship at the middle.

I think you should read the rules again. Currently minimum weight and fuel tank size is:

• LMS
  • LMP1 diesel: 900 kg, 81 liter
  • LMP1 petrol: 900 kg, 90 liter
  • LMP2: 825 kg, 80 liter
• ALMS
  • LMP1 diesel: 925 kg, 81 liter (+ pit fuel storage tank mounted higher)
  • LMP1 petrol: 880 kg, 90 liter
  • LMP2: 800 kg, 90 liter

[gwyllion]

Originally Posted by hcl123

In ALMS

P2 - 775Kg - the quasi P1 4L V8 petrol engine tipical 620 HP at 10K(F1 has 2,4L petrol and ~740HP at 19K rpm,... example that shows that maybe i'm being a little conservative !)
correponds to 0,8 HP for each Kg of weight

P1 diesel 995Kg - V12 730HP
corresponds to 0,73 HP for each Kg of weight!

Again you seem to have the numbers wrong.

The minimum weight for LMP2 is 800 kg. The displacement of the V8 is limited to 3.4 liter and because of an air restrictor the engine produces 500 hp (at most 550 hp I would say). That is 0,68 hp/kg.

For P1 diesel the minimum weight is 925 kg. The engine output is unknown but your estimate of 730 hp seems fine. That is 0,78 hp/kg.

[bludvl_x19]

Originally Posted by gwyllion

I think you should read the rules again. Currently minimum weight and fuel tank size is:

• LMS
  • LMP1 diesel: 900 kg, 81 liter
  • LMP1 petrol: 900 kg, 90 liter
  • LMP2: 825 kg, 80 liter
• ALMS
  • LMP1 diesel: 925 kg, 81 liter (+ pit fuel storage tank mounted higher)
  • LMP1 petrol: 880 kg, 90 liter
  • LMP2: 800 kg, 90 liter

What is the Pit Fuel Storage Tank? Does it serve as an effective power break over the Petrol engined LMPs?

Mick

[gwyllion]

From http://www.imsaracing.net/2007/alms/...in%2007-18.pdf

Commencing 28 August, 2007 cars running the IMSA mandated Shell V-Power Diesel “LM-24” are permitted to raise their pit fuel storage tank to 250cm.

If the fuel storage tank is higher, the diesel will flow a bit faster. This rule waiver was introduced because Audi lost time when refueling.

[bludvl_x19]

Ok, so it's just a refuelling rig then. Why do they need it higher? Is it because the diesel is stickier than Petrol. Ivunderstand the effect of raising it to make it flow faster, but I don't understand why they have done it. About how much time did they Audi's lose before the raise?

Mick

[chewymonster]

Originally Posted by bludvl_x19

Ok, so it's just a refuelling rig then. Why do they need it higher? Is it because the diesel is stickier than Petrol. Ivunderstand the effect of raising it to make it flow faster, but I don't understand why they have done it. About how much time did they Audi's lose before the raise?

Mick

Yes it makes for a quicker refill. It doesn't make sense if it takes longer to fill up 81 liters vs. 90 liters. Only fair as the diesels had to compromise with the smaller fuel tank.

[chewymonster]

Originally Posted by Spyderman

Erm...37,5% larger engine displacement for the P1 diesels in relation to the petrol engines comes to mind. (this single tiny little advantage is not only referent to the LMS)

Do you know that two valve engines get bigger restrictors than four valve engines? Who would have thought that different engine technologies would have different rules?

ps: Porsche will be using an Audi diesel in its cars very soon.

[Spyderman]

Yes,in their SUV's.

[bludvl_x19]

Mick

[Mal]

That is not so far fetched when you read about this: http://www.autocar.co.uk/CarReviews/...ncepts/231984/

[Spyderman]

No Mal it's not!
Unfortunately Porsche will have to use diesels in their cars in the future (starting with their SUV's), but the philosophy will still be that the diesels will be the "cost saving/ecomical/green" end of the spectrum , rather than the "performance" end of the spectrum.

[Mal]

If Audi get the R8 TDI right it could well change that perception. To have the level of torque that engine gives makes perfect sense for a high performance sportscar in the modern world. Its real world performance on real roads is likely to blow its competition away.

[Spyderman]

Well according to some, R8 V10 is done deal. 5.2L V10 NA 386kw(525ps)/540Nm, manual and R-Tronic, 40% LSD, around €135-140K base price in Germany, 0-100km/h: 4.0s, 315km/h...
Car is already in Audi ELSA program.
It appears that even Audi are hedging their bets with a V10 gasoline powered car.

[gwyllion]

Originally Posted by Mal

That is not so far fetched when you read about this: http://www.autocar.co.uk/CarReviews/...ncepts/231984/

The man who dreams about V12 diesels

@Spyderman: Your information is wrong. See the end of the above article:

But will that make the R8 V12 TDi the range-topping option in the range? “No, there will be a faster gasoline one.”

“With a new, high rpm V10,” I asked.

“No, guess again.”

“The twin-turbo, 572bhp RS6 V10? In an R8? Next year? Really?”

Hatz just smiled and nodded (that’s how Autocar news scoops are made these days).

More in Audi RS8 will get turbo V10

[Spyderman]

Yes, according to the same source as my other information Audi has indeed build test mule that is using body kit from V12 TDI and beefed Graziano gearbox(mid engine version of 599 gearbox in fact), currently in manual version(on that test mule)... 580ps/700Nm, belive it or not CO2 emissions below any current R8(NA V10 included)! First performance run was very, very impressive also... 0-100km/h: 3.5s, 0-300km/h: 28s, 338km/h... BUT, price will be at or above LP560-4 level ...and we all know about the pricing politics that will come into play within the PAG/VAG.

[chewymonster]

Makes sense, the R8 with the RS6 engine will be a total beast. I think it will be priced a little under the LP 560. And very fuel efficient as you said.

[hcl123]

Originally Posted by gwyllion

Again you seem to have the numbers wrong.

The minimum weight for LMP2 is 800 kg. The displacement of the V8 is limited to 3.4 liter and because of an air restrictor the engine produces 500 hp (at most 550 hp I would say). That is 0,68 hp/kg.

For P1 diesel the minimum weight is 925 kg. The engine output is unknown but your estimate of 730 hp seems fine. That is 0,78 hp/kg.

I would say not, where did you got that numbers ?
Isn't the restrictors larger for P2 than P1 ?

I would say 600+ HP for the best P2 in race conditions.

For the diesels they still claim 650+ HP, but for sure they can do more than 700 HP.

Again the big difference is in the torque and efficiency of engines that in the diesels case, still don't pass the 6K rpm in normal race conditions. Petrols have more than 1 hundred years of developement and in F1 they can get pass 20K rpm, when pushed by telemetry to max output.

The big point is all engines can be pushed beyond normal conditions, dynamicly by the way of telemetry, but not with the danger of blowing up the engine, danger that is larger in the case of petrols because they heat up much more and faster than diesels. That is why F1 engines can reach ~20K rpm but i doubt that any one of them could last more than 3 hours in race at those levels.

The pwoer/wt should be much more close then. Nonotheless i'm glad that IMSA has put some true back into it. Afterall the P2 shuold be an inferior category.

[hcl123]

Originally Posted by Spyderman

No Mal it's not!
Unfortunately Porsche will have to use diesels in their cars in the future (starting with their SUV's), but the philosophy will still be that the diesels will be the "cost saving/ecomical/green" end of the spectrum , rather than the "performance" end of the spectrum.

Unfortune doesn't have anything to do with it. And no!... they might not have to use diesel.

Petrol engines without spark ignition are on the way. Direct Injection, and CCD /controlled auto ignition by heat compression could make petrol engines much more efficient and more powerful. A diesel engine on petrol !?...

http://www.greencarcongress.com/2007...es-benz-p.html

BMW as showned an identical prototype engine last year.

Marketing those wont be easy dhow, because the "traditional" sound of engines, that people associate with power, but is nothing more than fuel burning in the tail pipe, will be most gone by then.

[gwyllion]

Originally Posted by hcl123

I would say not, where did you got that numbers ?
Isn't the restrictors larger for P2 than P1 ?

I would say 600+ HP for the best P2 in race conditions.

No, restrictor for P2 is smaller than P1. Just look at http://www.mulsannescorner.com/chass.../2008LMP12.pdf.

• LMP1: 3000 - 3500 cc -> 2 x 34.3 mm or 1 x 48 mm restrictor
• LMP2: 3200 - 3400 cc -> 1 x 42.9 mm restrictor

Just do the math. 48 mm diameter gives 1810 mm^2 area and 42.9 mm means 1445 mm^2. So LMP1 has 25% bigger restrictor and theoretically 25% more power.

530 hp for LMP2 and 660 hp for LMP1 petrol seems like a good estimate.

Also look at "official" number of engine builders:

• Acura ARX-01B: 500+ hp
• Judd DB: 510 hp @ 10 500 rpm and 480 Nm (see here)
• Mazda MZR-R: 500 hp and 540 Nm (see here)
• Porsche RS Spyder: 478 hp and 370 Nm (see here)
• Zytek ZG348: 510 hp and 436 Nm (see here)

Your 600+ hp is huge overestimation.