He didn't say SHOULD not, he said IMPOSSIBLE, which is correct. He also did not say ceramic. The carbon brakes found in F1 and some other top tier cars do not work on the road. You can't get enough heat into them. The carbon brakes on your road car are carbon ceramic.
All engines are handicapped. Because the engine rules aren't as restrictive as (e.g.) F1, they handicap everyone for equality. You can't make apples to apples comparisons with rules like that, ie for most multi-marque racing series.
I can hear Bernie's response now... "No single team is bigger than F1 and F1 isn't going to change to please just one man... well, I mean other than myself."
That's a very tough question. Diesel engines in general are more "powerful" than gas engines at low rpms so if you have enough torque to have reasonable gearing (you have to stretch out the torque band, at the expense of reducing torque multiplication) you have a winner. I guess the other trick with diesel engines is keeping the throttle responsive. Gas engines though, will always have more peak HP and could therefore be considered more "powerful". The operating rpm range of either type of engine in a race situation is fairly narrow so it probably comes down to being able to keep a flatter torque curve after the restrictor comes into play (engines are equalized by use of intake restrictors). Perhaps diesels are better at this.
You also have to factor in that diesel engines are (comparitively) simpler engines by design and therefore more reliable, more robust due to requiring a stronger block, are lower stressed engines than their petrol counterpart and are naturally more fuel efficient and therefore require less fuel stops. When it comes to the the equalization between petrol and diesel at LeMans, the teams with petrol engines would like to see the diesel runners having to use even smaller fuel tanks so they have to make the same number of fuel stops as the petrol cars (the diesel runners already run smaller fuel tanks than the petrol cars but the petrol runners still say they're too large) and they want more engine restrictions for diesel engines (smaller restricitors on intakes, smaller turbo's etc.). Every year the diesel restrictions get tightened slightly but as soon as the diesel runners feel they're losing too much of their advantage they threaten to leave. The problem with this threat is that it comes from Audi and Peugeot, big manufacturers, whereas the petrol runners in this catagory tend to be smaller, independent race teams. Were the likes of Ferrari, Porsche, Mercedes, BMW, Aston Martin to all suddenly commit and guarantee to enter LMP1 cars for a guaranteed number of years, then the organisers would probably risk losing Audi and Peugeot, but not for the smaller teams. To be fair to Audi and Peugeot, their argument is that they have spent alot of money developing their diesel cars to be as fast and efficient as possible and that to handicap them back to the same level as petrol cars makes no sense. If other teams want to race against them on a level playing field, then they should enter a diesel car. It's a bit like running the 100 metres in the olympics with two classes of athlete on track, "drug assisted" and "clean". The first time you run it, they all start from the same point and the "clean" runners stand no chance. So the "clean" runners say they should start 15metres ahead of the "drug assisted" runners to make the race equal. Trouble is, all the "drug assisted" runners are the big stars and they threaten to walk if this rule is brought in, so the organisers settle on a 5metre head start and the big stars still win. The "clean" runners still complain they can't win, the "drug assissted" runners complain that if they no longer have an advantage they've wasted thier money on the drugs to go faster and besides, all the "clean" athletes have to do to win is take the drugs. The risk for LeMans is that should either Audi or Peugeot decide not to enter one year and there is only one diesel team in LMP1 then you no longer have a real race, you have a demonstration run and the image of LeMans gets damaged. To be honest, over the past few years I've lost a bit of interest in who wins LeMans outright as the result was fairly predictable. Instead, I've tended to pay more attention to the GT classes as this to Me is the true spirit of LeMans.
Very true and that's why I'm always so puzzled when people on here complain bitterly about the unfair treatment Ferrari gets from the FIA and then demand that Ferrari leaves F1 and instead picks up Le Mans racing. Can you imagine the burst of outcries on here when Ferrari has to give up its hard earned advantage by carrying weight around and loose the next race because of it? F1 has many flaws but it still leaves the manufacturers a lot more playroom than Le Mans does. PS: In case anybody missed it: Ferrari won Le Mans last year and this.
Thanks for the time you guys took to explain. I'm still pretty new to Le Mans, hence the silly questions. Appreciate the effort
At equal capacity, a diesel is inferior to a petrol engine. Until recently, under ACO regulations, Diesel engines were favoured in terms of capacity, supercharging, weight limits and fuel tank size. Where a petrol engine was 4000cc max. and only atmospheric , a diesel engine was allowed 5000cc + turbo. The difference was about 80 hp, about 15% power advantage Diesels have 40% better torque giving better accelarations out of corners. Together, that was giving between 5 and 8 sec. advantage per lap according to Pescarolo. This, added to better fuel economy for Diesels, giving them longer range, less refuelling stops, etc... In all, it was calculated that Diesels benefited from an average of 14 sec. per lap at Le Mans. It's very diffilcut to give equivalence between 2 types of engines (2 or 4-stroke, petrol/diesels), but Le Mans wrote the rules to keep AUDI in competition after the other constructors left, with a bias towards Diesel engines.
Yes. Developing Diesel engines requires a know-how that virtually doesn't exist in the petrol centered world of the smaller racing car manufacturers.
Diesels make perfect sense for Audi and Peugeot as they use them widely in their road cars. Diesels would make zero sense for Ferrari.
Not to be argumentative, but let me correct you: by inferior you must mean "has less peak hp". You might also (in addition) mean "has a peakier torque curve". Also, I assume that by capacity you mean displacement. For all vehicles, but especially for race engines, we don't care about displacement. We care about power per kg. We also care about fuel efficiency since a more efficient engine requires the car to either carry less fuel or for it to go longer on a fillup. Maybe if Ferrari made a Le Mans car, ACO would be encouraged to remove the bias towards the diesels. No one wants to see Audi or Peugeot beat Ferrari!
I think Ferrari on their own might not be enough. Add in a couple of the other big names I've mentioned though and I'm sure they'd seriously consider it.
Not strictly true. JUDD developed a competitive V10 Diesesl engine for endurance. Private teams refused to use it and prefered the JUDD petrol engines instead, on the ground that there was no transmission on the market strong enough to handle the torque. That defeated their arguments when they complained to the ACO about the bias towards Diesels and their unavailability for private teams. Also, the 2 teams that challenged the Diesel rules (Pescarolo and ORECA) weren't against using a Peugeot Diesel on loan from the factory!!
To illustrate what I said, at equal displacement an atmospheric petrol engine will develop more power than its Diesel equivalent of the same size. Up to 300 hp per litre can be obtained with an atmospheric petrol engine on the bench. The same size Diesel engine will be lucky to reach 100hp/L. The difference is reduced with supercharging. A supercharged petrol engine can reach 1000hp/L (BMW F1 4cyl turbo as fitted on Brabham F1) and some went as far as 1500hp/L for short period. Recently, a turbo Diesel obtained 800hp/L during bench testing. These figures come from Riccardo, the engineering firm in Britain that does research works for most motor manufacturers. So the gap is closing, but will never be closed. I agree with the torque curve which is in favour of the Diesel by a long shot. But the advantage of stronger bottom torque is negated by the need of ever stronger (read heavier) transmissions to handle it! Where I agree with you is that in term or fuel efficiency or "rendement calorifique" as the French say, the Diesel is way above petrol engine. One of the reasons it is so popular in cash-strapped Europe is that it gives between 30 and 40% more miles to the gallon on ordinary cars!! Obviously it doesn't translate as the same in our wallet - the taxman saw to that and unfairly taxes Diesel fuel more than petrol.
Agreed, but I am saying that we do not care about power per liter (of displacement), we care about power per kg. Is there any info on that for diesel vs gas? negated? perhaps the weight penalty is ok. it could be like marginal tax rates: the tax man takes more as a percentage but you still have more cash. i'm not saying that's the case, i'm just saying it may not be an even-up trade.
The weight penalty may well be deemed acceptable as the extra weight is due to the extra strength required (as already mentioned), which in itself leads to extra reliability. This is the difference between F1 and GT/Endurance racing, extra weight (provided it's not too excessive) is not always detrimental when it comes to achieving your goal of winning the race. A LeMans winning car has to be alot more durable than a Grand Prix winning F1 car.
You may not care, but most of motor racing regulations are based on displacement, therefore the power per litre is the cornestone of any thought in the matter. Although there is nothing to prevent them, it would not come to mind to a constructor to enter Formula One with a Diesel engine subjected to the same rules as a petrol engine (2.4L atmospheric V8, rev. limited to 17,000rpm).
Let's put it that way; Diesel engines develop enormous torque at low revs and put lots of stress on transmission. Gearboxes and driveshafts were the Achiles heel of AUDI when they went to Diesel, and they had to design at huge cost new units before they obtained the reliability then wanted. Most private teams have only access to readily available transmissions on the market like Hewland, Quaife, Xtrac, etc... which were designed around petrol engine parameters and cannot handle safely Diesel torque for long. That was one of the reasons why Pescarolo declined using the V10 Diesel JUDD engine and kept a petrol engine: he couldn't buy an adequate gearbox over the counter.
ah, good point. unfortunately euro laws also (apparently) heavily penalize large displacement when instead they should penalize poor fuel economy.
yes, and i don't think you need to further explain that. it is well understood. my point, which you did not adequately refute, is that the added weight of the gearbox, due to the higher strength required, may be a net benefit. i can see where the customer teams are left unable to use diesels, that's unfortunate.
