[WEC] LMP Future Regulations (was Le Mans EVO rules - now hypercar rules)

[Speed-King]

240-300 hp/liter

The Porsche 935/956-engine must have been close to that, at least in IMSA-trim without fuel limitations.
Also 1980s F1-engines and the 2.1l (?) from the AAR Eagles come to mind.

But that was of course with a petrol engine, and not being a tech-head, I have no idea if it is in any way applicable to Diesel engines...

[gwyllion]

With petrol that specific power output is easy.

The AER and AMR LMP1 turbo engine produce 550+ hp from 2 liter (275+ hp/liter).

In F1 the current V8 engines produces 750 hp from 2.4 liter (312 hp/liter) and previous V10s reached almost 1000 hp with 3.0 liter (333 hp/liter).

I highly doubt that those numbers can be achieved with race diesel engines.

[Félix]

My point is just that the challenge is clearly not hard enough now. It's not Audi's fault. Still, the R18's program goal (to make me - and others - look at Audis like technologically cool cars because they overcame a difficult challenge in Le Mans-style racing) is not reached for me because of that.

I personally think they could still push the boundaries quite a bit more. I think they could survive the 50hp deficit that would come with a smaller inline four diesel by using KERS, still benefiting from truck-like torque and optimizing their superior chassis even more. With the opponents they are running against and the torqueless engines the rules force on them, I find it outrageous that the rules still give the diesels a power advantage on top of the vastly superior torque figure that pulls them up to top speed a lot faster than anyone else. The diesel on-track battle will have to be extremely good to make me forget about all this. That's just me; some other hardcore fans seem to be happy with the way things are, seemingly believing that the 2 factory outfits are way ahead solely because of their resources and that the rules are all right - that the different engine types have nothing to do with the huge gap.

Now comparing road car engines is never perfect, however looking at the 3 engine types found in the 3-series BMW shows how well a diesel can do:
-the M3 V8 is good for 420 horses from 4 liters. It's the fastest 3 series.
-the 3 liter turbo engine is now good for 320 horses. It's not as hardcore as it could be but it's easy to imagine a 400-ish hp version of it if there wasn't a V8 in the M3 with more or less similar performances.
-the 3 liter diesel make 280-some horses and much more torque than any other 3 series engine. The car gets performance figures (various accelerations) closer to an M3 - with a bigger atmospheric engine - than to those of the turbo petrol engine of the exact same size.
Now if the diesel engine was "equalized" (given the displacement advantage it has over petrol engines) like under ACO rules, it would be 4.3L (1.08*atmo) or 5.5L (1.85*turbo).
**Again, this doesn't mean much and these are just numbers, but I think it shows how a diesel engine can not to be bigger than a petrol engine and still give better performance.

[JAG]

That's just me; some other hardcore fans seem to be happy with the way things are, seemingly believing that the 2 factory outfits are way ahead solely because of their resources and that the rules are all right - that the different engine types have nothing to do with the huge gap.

There's a middle ground, one that believes diesels, particularly their torque advantage, may need to be looked at again. But also acknowledgment, in this first year of regs., petrol cars have not shown all their cards, for numerous reasons.

[Félix]

Originally Posted by JAG

There's a middle ground, one that believes diesels, particularly their torque advantage, may need to be looked at again. But also acknowledgment, in this first year of regs., petrol cars have not shown all their cards, for numerous reasons.

The diesel rules are giving the majority of LMP1 entrant a great non-race since 2006. Every year there have been people on that middle ground believing things were almost equal... but after constant rule adjustments, we have yet to get to what could remotely look like a level playing field. To me the odds of seeing a good year of racing at the top between petrol and diesel cars are lower than those of seeing the category implode. (OK I've just been reading the Bear's last column...)

[gwyllion]

Originally Posted by Félix

Now comparing road car engines is never perfect, however looking at the 3 engine types found in the 3-series BMW shows how well a diesel can do:
-the M3 V8 is good for 420 horses from 4 liters. It's the fastest 3 series.
-the 3 liter turbo engine is now good for 320 horses. It's not as hardcore as it could be but it's easy to imagine a 400-ish hp version of it if there wasn't a V8 in the M3 with more or less similar performances.
-the 3 liter diesel make 280-some horses and much more torque than any other 3 series engine. The car gets performance figures (various accelerations) closer to an M3 - with a bigger atmospheric engine - than to those of the turbo petrol engine of the exact same size.

Where did you get your acceleration numbers? For a coupe with a manual gearbox, the BMW website gives the following numbers:

• 335d: 1645 kg, 210 kW (286 hp), 580 Nm -> 0-100 km/h in 5.9 sec
• 335i: 1600 kg, 225 kW (306 hp), 400 Nm -> 0-100 km/h in 5.5 sec
• M3: 1555 kg, 309 kW (420 hp), 400 Nm -> 0-100 km/h in 4.8 sec

BTW the two turbo engines are capable of quite a bit more. E.g., a different engine map from AC Schnitzer (and different exhaust for M3) gives:

• 335d: 230 kW (313 hp), 680 Nm -> 0-100 km/h in 5.7 sec, max speed 258 km/h
• 335i: 265 kW (360 hp), 520 Nm -> 0-100 km/h in 4.8 sec, max speed 294 km/h
• M3: 331 kW (450 hp), 420 Nm -> 0-100 km/h in 4.7 sec, max speed 321 km/h

Originally Posted by Félix

Now if the diesel engine was "equalized" (given the displacement advantage it has over petrol engines) like under ACO rules, it would be 4.3L (1.08*atmo) or 5.5L (1.85*turbo).

Sorry, I don't understand your calculation.

The 335d needs a displacement of 3.0 liter to produce 210 kW. If it has to produce 309 kW like the M3, it would need a displacement of 4.4 liter (= 3.0 * 309 / 210). That is 10% more displacement than the M3.
With the Schnitzer numbers it would need 4.3 liter (= 3.0 * 331 / 230) or 8% more than the M3.

In the ACO rules the difference in displacement between NA petrol (3.4 liter) and turbo diesel (3.7 liter) is 9%. Mmm, coincidence?

[gwyllion]

Originally Posted by Félix

The diesel rules are giving the majority of LMP1 entrant a great non-race since 2006. Every year there have been people on that middle ground believing things were almost equal... but after constant rule adjustments, we have yet to get to what could remotely look like a level playing field. To me the odds of seeing a good year of racing at the top between petrol and diesel cars are lower than those of seeing the category implode. (OK I've just been reading the Bear's last column...)

Some statistics for you.

The difference in laps between the first Audi/Bentley and the first non-Audi/non-Bentley in the pre-diesel years:

• 2000: 369 laps vs 345 laps -> 14 laps
• 2001: 321 laps vs 298 laps -> 23 laps
• 2002: 375 laps vs 359 laps -> 16 laps
• 2003: 377 laps vs 360 laps -> 17 laps
• 2004: 379 laps vs 361 laps -> 18 laps
• 2005: 370 laps vs 368 laps -> 2 laps (heavily restricted R8)

The difference in laps between the first diesel and the first petrol:

• 2006: 380 laps vs 376 laps -> 4 laps
• 2007: 369 laps vs 358 laps -> 11 laps
• 2008: 381 laps vs 362 laps -> 19 laps
• 2009: 382 laps vs 373 laps -> 9 laps
• 2010: 397 laps vs 369 laps -> 28 laps

BTW I totally agree that the rules are not yet correct. I would like to see the ACO decrease the minimum weight for petrol cars from 900 to say 850 kg as compensation for the torque advantage of the diesel.

[Félix]

Are we really using numbers from a tuned street BMW to prove the ACO equalization formula is right??? Let's not even get into the hundreds of details that can skew that comparison...

The BMW diesel gives performance that is at times better than the other engines and at all times better than what you would expect from the numbers. But what really tops it off is that ACO rules suggest that it is MUCH too small because a diesel has to be 8% bigger than an equivalent atmo petrol engine or 85% bigger than a turbo petrol. Such an advantage would simply take it out of the 2 other engines' league.

[Félix]

Originally Posted by gwyllion

Some statistics for you from the pre-diesel years. The difference in laps between the first Audi/Bentley and the first non-Audi/non-Bentley:

• 2000: 369 laps vs 345 laps -> 14 laps
• 2001: 321 laps vs 298 laps -> 23 laps
• 2002: 375 laps vs 359 laps -> 16 laps
• 2003: 377 laps vs 360 laps -> 17 laps
• 2004: 379 laps vs 361 laps -> 18 laps
• 2005: 370 laps vs 368 laps -> 2 laps (heavily restricted R8)

The difference in laps between the first diesel and the first petrol:

• 2006: 380 laps vs 376 laps -> 4 laps
• 2007: 369 laps vs 358 laps -> 11 laps
• 2008: 381 laps vs 362 laps -> 19 laps
• 2009: 382 laps vs 373 laps -> 9 laps
• 2010: 397 laps vs 369 laps -> 28 laps

BTW I totally agree that the rules are not yet correct. I would like to see the ACO decrease the minimum weight for petrol cars from 900 to say 850 kg as compensation for the torque advantage of the diesel.

A non-race is cars from the diesel class starting from the first six places and never being overtaken during the race. The factories are always going to dominate. I'm just asking that they do it with equal engine performance, with cars that look like they're running in the same class. And I'd like to see a modern-day Lammers being able to outbrake the diesels during the first stint.

[AGD]

Ok, who cares about LMP1 and GTE, I want to discuss LMP2. What is the justification for the Judd getting a restrictor reduction? I don't mind this being done if there was a slight error in the initial rules, but was this done simply because the Judd wasn't as fast as the Nissan? I don't approve of balancing done just for the sake of ensuring everyone has equal power. They might as well just run spec FLM engines in that case. I had hopes for LMP2 being a really good class, but between this, the cost capped confusion, and the difference between "real" stock engines and stock derived race engines indicates that LMP2 is a "true" ACO spec!

As for LMP1, I don't know if the diesel-petrol rules are balanced, but I don't watch this form of racing expecting to see 12 cars finish on the lead lap at the end of 24 hours. I don't expect to see that many cars on the lead lap at the end of 1 hour. I do, however, expect that the competition for the 24 hours occurs months before the actual race in engine rooms, dyno rooms, and test tracks across the globe. Please don't take that away from me. Those of you who want spec or pseudo-spec racing have plenty of other options, but the rest of us don't have many other options.

[gwyllion]

Originally Posted by Félix

Are we really using numbers from a tuned street BMW to prove the ACO equalization formula is right??? Let's not even get into the hundreds of details that can skew that comparison...

Please read my previous message. I am using the official numbers provided by BMW!

Originally Posted by Félix

The BMW diesel gives performance that is at times better than the other engines and at all times better than what you would expect from the numbers.

I have a hard time finding accerelation numbers for the 335d. The best I could do are the following numbers for a tuned 335d (340 hp, 660 Nm):

• 0 - 40 km/h: 1.6 s
• 0 - 60 km/h: 2.5 s
• 0 - 80 km/h: 3.7 s
• 0 - 100 km/h: 5.6 s
• 0 - 120 km/h: 7.5 s
• 0 - 140 km/h: 10.2 s
• 0 - 160km/h: 13.1 s
• 0 - 180 km/h: 17.9 s

source: http://img46.imagevenue.com/aAfkjfp0..._122_987lo.jpg

I found the following number for the M3 E90 (420 hp, 400 Nm):

• 0 - 40 km/h: 1.7 s
• 0 - 60 km/h: 2.6 s
• 0 - 80 km/h: 3.7 s
• 0 - 100 km/h: 4.8 s
• 0 - 120 km/h: 6.4 s
• 0 - 140 km/h: 8.2 s
• 0 - 160km/h: 10.2 s
• 0 - 180 km/h: 12.8 s
• 0 - 200 km/h: 15.7 s

source: http://img440.imageshack.us/img440/7373/43908515yh8.jpg

Those numbers confirm that official BMW 0-100 km/h times.

The tuned 335d can keep up during initial acceleration because of its huge torque, but from 80 km/h on the M3 pulls with its extra 80 hp.

[gwyllion]

Originally Posted by AGD

Ok, who cares about LMP1 and GTE, I want to discuss LMP2. What is the justification for the Judd getting a restrictor reduction? I don't mind this being done if there was a slight error in the initial rules, but was this done simply because the Judd wasn't as fast as the Nissan? I don't approve of balancing done just for the sake of ensuring everyone has equal power.

I doubt it was an error. The ACO has years of experience equalizing the performance of NA petrol engines with different displacements. For instance, the Zytek 4.5 V8 produced similar power as the Judd 5.5 V10.

[gwyllion]

Originally Posted by gwyllion

I have a hard time finding accerelation numbers for the 335d. The best I could do are the following numbers for a tuned 335d (340 hp, 660 Nm):

• 0 - 40 km/h: 1.6 s
• 0 - 60 km/h: 2.5 s
• 0 - 80 km/h: 3.7 s
• 0 - 100 km/h: 5.6 s
• 0 - 120 km/h: 7.5 s
• 0 - 140 km/h: 10.2 s
• 0 - 160 km/h: 13.1 s
• 0 - 180 km/h: 17.9 s

source: http://img46.imagevenue.com/aAfkjfp0..._122_987lo.jpg

I also found the numbers for the standard 335i (306 hp, 400 Nm):

• 0 - 40 km/h: 1.8 s
• 0 - 60 km/h: 2.7 s
• 0 - 80 km/h: 4.2 s
• 0 - 100 km/h: 5.6 s
• 0 - 120 km/h: 8.0 s
• 0 - 140 km/h: 10.2 s
• 0 - 160km/h: 13.0 s
• 0 - 180 km/h: 16.9 s
• 0 - 200 km/h: 20.7 s

source: http://www.sportauto-online.de/super...75.html?show=4

The 335i (standard) does a good job keeping up with the slightly more powerfull 335d (tuned). This can be explained by the weight difference, which result in an almost identical weight-to-power ratio: 1610 kg or 5.3 kg/hpfor the 335i coupe vs 1766 kg or 5.2 kg/hp for the 335d touring.
BTW the weight-to-power ratio shows why the M3 is so much faster in acceleration: 1610 kg for 420 hp gives 3.83 kg/hp.

For what it is worth, the 335i has better handling than the heavy 335d.

• slalom 18 m: 67.6 km/h for 335i vs 63.9 km/h for 335d touring
• short Hockenheim track: 1:17.6 min for 335i vs 1:19.8 min for 335d

[Félix]

The point is NOT the different road BMWs with different gearboxes (and 1000 other things) that make comparing performance numbers impossible.

The point, I repeat, is that under ACO rules the way to get "equivalence" between the 3 road engines (between their specs to be precise) would be with a diesel engine 1.85x bigger than the turbo petrol engine or 1.08x bigger than the atmo petrol engine. Now tell me that looks fair. You can even try to extrapolate from road car numbers if you like, but the point remains that giving diesels that big of an advantage is overkill.

Additionally, if we want to keep talking about road cars, the ACO rules have little relevance because nobody makes diesel engines that big for the road.

[MitchZ06]

Er yeah they do actually, infact GM makes a 6.6l V8 turbo diesel....

[Félix]

Originally Posted by MitchZ06

Er yeah they do actually, infact GM makes a 6.6l V8 turbo diesel....

I know, Ford and GM make big pickup truck engines. They're great if you want to tow a house. Where I'm from, school buses are built out of those pickups. Dodge will put a Cummins engine in your pickup as well - but it's much closer to the engine you find in heavy equipment than to the inline four found in the Peugeot I rented last month.

BMW and Mercedes made a V8, VAG had the Touareg V10 and the 6-liter Audi V12. They don't make them anymore. Audi makes a 4.2 diesel V8, but I'm sure it sells much less than the smaller diesels available in the same cars.

Big diesels are not used in road cars. Endurance racing is good for testing engine tech that applies to road cars.

[gwyllion]

Originally Posted by Félix

BMW and Mercedes made a V8, VAG had the Touareg V10 and the 6-liter Audi V12. They don't make them anymore. Audi makes a 4.2 diesel V8, but I'm sure it sells much less than the smaller diesels available in the same cars.

The Q7 V12 TDI is still on sale in Europe.

Land Rover sells the Range Rover TDV8, which has a 4.4 V8 diesel engine. That car is not designed to tow a house

Originally Posted by Félix

Big diesels are not used in road cars. Endurance racing is good for testing engine tech that applies to road cars.

So you must the 2011 LMP1 rules which have decrease the displacement for diesel engines from 5.5 to 3.7 liter

Small V8 petrol engines revving at 11000 rpm are not that relevant for road cars either. I doubt that many Atom 500 V8s, Caparo T1s or Radical SR8s have been sold last year.

[Félix]

Originally Posted by gwyllion

The Q7 V12 TDI is still on sale in Europe.

Sorry Wikipedia said otherwise but I concur that they must still sell a few hundreds yearly - for the price of a small house. Mea culpa.

Land Rover sells the Range Rover TDV8, which has a 4.4 V8 diesel engine. That car is not designed to tow a house
So you must the 2011 LMP1 rules which have decrease the displacement for diesel engines from 5.5 to 3.7 liter

Small V8 petrol engines revving at 11000 rpm are not that relevant for road cars either. I doubt that many Atom 500 V8s, Caparo T1s or Radical SR8s have been sold last year.

Yes! We finally seem to agree. Big diesel engines are only used in a few big luxury SUVs. The ACO was right to make the diesels smaller; they just didn't go far enough. It's especially obvious that they didn't go far enough when we look at the small atmo V8s and at the stupid 10,000+ rpm they have to rev to still be beaten badly by the diesels.

As I've written months ago, the ACO should alternatively have left the option open for bigger petrol engines while giving them very small restrictors so they can't rev but still can achieve credible torque numbers if it wanted to keep on giving diesels big displacement. That's a far better solution for road car manufacturers who are used to building bigger V8s, V10s and V12s that don't rev over 8000rpm - and it's the solution they seem to favor on road cars with the development of direct injection to return decent fuel consumption and emission levels. (I'm thinking about the engines in the most recent Ferrari California, 458 and FF, both Lamborghinis and even all the 911s now have DFI - except GT3s)

Pescarolo is even proving that's a better solution this year by getting better fuel consumption from his castrated Judd without DFI - whilst certainly not outrunning anyone on the straights. It's an equivalence issue; they could change the rules on either end to make it less ridiculous. Thinking the basic engine size equivalence could remain that wrong for another race, nevermind the next 2-3 years makes me very sad and not optimistic at all about the class' future. (I hope it's all clear enough now!)

[gwyllion]

Originally Posted by Félix

Yes! We finally seem to agree. Big diesel engines are only used in a few big luxury SUVs.

And big luxury sedans, e.g., the current Audi A8 4.2 V8 TDI and untill recently BMW 740d/745d, Mercedes E400/E420 CDI, Mercedes S400/S420/S450 CDI.

Originally Posted by Félix

As I've written months ago, the ACO should alternatively have left the option open for bigger petrol engines while giving them very small restrictors so they can't rev but still can achieve credible torque numbers if it wanted to keep on giving diesels big displacement. That's a far better solution for road car manufacturers who are used to building bigger V8s, V10s and V12s that don't rev over 8000rpm - and it's the solution they seem to favor on road cars with the development of direct injection to return decent fuel consumption and emission levels.

The real trend is downsizing, i.e., replacing NA engines with smaller turbocharged engines, at least for non-sportscars. A good example is the Fiat 2 cilinder that just won the engine of the year award.

The ACO toke the most convenient solution by replacing the big LMP1 engines with the smaller LMP2 engines.

BTW downsizing is also occuring in sportscars. The Nissan R-GT has a V6 turbo, the McLaren MP4-12C has a V8 turbo, the next BMW M5 will get a V8 turbo instead of a V10, the Ferrari Enzo successor will get a V8 turbo instead of a V12, Audi is said to go for smaller displacement (e.g., V8 turbo instead of V10 turbo) for their future RS cars, ...

[MitchZ06]

The R35 Nissan GT-R actually has a bigger turbo V6 than the straight 6 in the old R34 (3.6l vs 2.6l)....

[gwyllion]

Originally Posted by MitchZ06

The R35 Nissan GT-R actually has a bigger turbo V6 than the straight 6 in the old R34 (3.6l vs 2.6l)....

If you want to almost double the power output (530 hp vs 276 hp), you have to do something

[gwyllion]

Originally Posted by gwyllion

BTW downsizing is also occuring in sportscars. The Nissan R-GT has a V6 turbo, the McLaren MP4-12C has a V8 turbo, the next BMW M5 will get a V8 turbo instead of a V10, the Ferrari Enzo successor will get a V8 turbo instead of a V12, Audi is said to go for smaller displacement (e.g., V8 turbo instead of V10 turbo) for their future RS cars, ...

Two more examples which came to my mind. Bentley recently announced a 4.0 V8 direct injection turbo engine for the Continental GT. Aston Martin is rumored to move from V8 and V12 engines to turbocharged straight 6 engines.

[Bentley03]

Originally Posted by gwyllion

A quick and dirty calculation to determine the impact of the performance balance changes.

In Spa the winning Peugeot did 161 laps in 6 hours, while the best petrol (Pescarolo) only did 156 laps. That means an average race lap time of 2:14.9 and 2:19.4 respectively. This puts the petrols within 3.3% of the diesels.

During the race the best diesel and best petrol did 6 pitstops. According to the ACO petrol cars will gain 22 sec every pitstop. That means 132 sec or around 1 lap over the whole race. Lets assume that the best diesel only did 160 laps. That means an average race lap time of 2:15.8 for the best diesel. This puts the petrols within 2.6% of the diesels.

The expert source of Mike says that 10% more power is worth around 2.6 sec at Le Mans. So a restrictor break of 3% is probably worth around 0.8 sec at Le Mans. Lets assume that means around 0.5 sec in Spa or 80 sec over the whole race. That means an average race lap of 2:18.9 for the best petrol. This puts the petrols with 2.3% of the diesels.

That is still outside the 2% rule

Trussers has given his take on the adjustments in his latest blog entry. He very much focuses on the impact of the reduced diameter of the diesel refuelling hose.

Trussers Blog

[gwyllion]

I think that Paul is exaggerating the impact of the restrictor break when he writes "the extra air entering the engine should provide enough horsepower to reduce lap-times by up to a couple of seconds." According to Henri Pescarolo it is only worth 1 second.

[MulsanneMike]

Originally Posted by gwyllion

I think that Paul is exaggerating the impact of the restrictor break when he writes "the extra air entering the engine should provide enough horsepower to reduce lap-times by up to a couple of seconds." According to Henri Pescarolo it is only worth 1 second.

Yes, at around 2%, if taking the weight break, that's around 10-12hp. That will barely budge the lap time.