[hcl123]

Originally Posted by arakis

clearly you haven't got a clue what you are talking about.
Racing engines be it disels or petrol are always built to specification, to last only the dsignated time of the race plus some leway, the closer you built the engine to the race distance more power, torque it will have. prof: Peugeut this year!

Clearly its you don't have a clue. As hard as it is for you to imagine torque is independent of the speed of the engine. Specific torque that is. Specific torque is a function of how energetic combustion is inside a cylinder in each power stroke. The first way to achieve this, is to inject more fuel inside the cylinders for each power stroke. That is essentially the only route taken by petrol engines. The other way is to make each of those power strokes more efficient by applying thermodynamic principles of pressure and heat. And this is the route that diesels take to advantage, because when combustion starts for each power stroke in a diesel, pressure and heat inside the cylinder is already higher than petrol, that can only achieve those initial "diesel like" conditions of pressure and heat after combustion has started for a while.

And in here is one of the unfair rules, in terms of BTU, petrol( racing petrol) and diesel are very much like the same, no reason for diesels to have a 9 liter less tank. Only that diesels are substantially more thermodynamic efficient.

Specific POWER is a PRODUCT of torque X the speed of the engine ( the revs), not the speed of the car. The problem is to attain those high efficient RPM. If there weren't any load on the engine, the weight of the car, aerodynamic pressure and the friction of the tires on the tarmac... a petrol engine with its high revs would win now (more specific max power "HP" ), because diesels haven't quite reached yet the mechanical balance needed to achieve more high revs than now, that they can "FOR SURE" reach in the short future.( not as much as petrols but clearly 8K RPM is not that hard)

Now we can see why rules have been bent always in favor of petrol. Less weight on the car, less aerodynamic support, were put in place to REDUCE THE LOAD ON THE ENGINE essentially, favoring petrol. If they were concerned with "dangerous" top speeds they would have increased the weight of the cars to 1 ton... if they were concerned with corner speed stability they would have increased the minimal axle length between tires, and the minimal tire size, and augmented the weight to lower corner speed. But a larger and heavier car definitely would have benefited diesels because of the much better torque, making petrol difficult to achieve high rates of power because the load on the engine would had been greater.

Originally Posted by arakis

Fact of life Horse power is the only thing that defines maximum speed, if you knew anything about physics you would know that, torque is for acceleration. any racecar, wants to be set up its gearing so that it reaches max speed at max hp! and bougaty veyron is a slow reving engine reaching its max power at 6000 rpm!!!!!

You contradict yourself... gearing is there to "facilitate" an engine to reach those higher levels of power, and though that linearity in a perfect condition " max speed at max power", is what is pursued, that often is the case... if seldom. Gearing is a mechanical "process" ( putted in simple terms) by which the "LOAD" on the engine is reduced, reducing the time that an engine takes to achieve those high levels of power in each of its stages. Because diesels have more torque, they can pass very well with less gear "stages"(audi case)... and the reason why an electric motor, which has a very short time lap between zero and max power and max torque( some generalize as instantaneous torque), and much higher power and torque to weight ratios, can pass very well without any gearing... or "transmission".

A W 16 8 liter Bugatty Veyron engine weight 400 Kilos !!!... has 16 cylinders in a poorly tested and so balanced configuration... no wonder it only reaches 6K RPM !... but it has a tremendous torque so it compensates to reach 1000 HP( power= torque x speed of engine), tough being a petrol engine, because it has 8 power strokes for each revolution of the crankshaft, instead of 6 power strokes for each revolution for the 5/6 liter V12s of aston martin and peugeot.

Originally Posted by arakis

Learn your facts first then start to educate everyone else, or even better listen to some very smart people here that actualy know what they are talking about, me excluded.

that is an understatement... for sure!

Originally Posted by arakis

porsche lmp2 engine was preaty close to f1 engine, its a 11000 rpm engine, and while it raced it was the best lmp2 engine!

For a 775 Kilo car, total weight, its not hard to imagine that it was fast alright. But in 2007, the audi R10 with 995Kilo, those audis were like dragging a 200Kg trailer competing with Penske porsche in ALMS... situation only fair to the corrupted minds of IMSA "oil" lubricated petrol heads, that demanded it... yet the Audi R10 won most of the races. Wonder why ??

Originally Posted by arakis

BTW engine torque means nothing, it doesent move the car, force pushing the tarmac trough tires is the only thing that matters, and to get to the tires you have to go trough gearing!!!!!!!!!!!!!!!!! you know big sprocket-little sporocket means more torque, less rpm, little sprocket -big sproket means less torque more rpm, guess witch is used by petrol witch by diesel

You contradict yourself again. That "force pushing the tarmac trough the tires" is torque not power... power is the "speed" you can "MULTIPLY THAT FORCE" in a specific unit of time, and that doesn't automatically translates to the "speed of the car" because there are several loads to account to... and the TIME TAKEN TO ACHIVE a "faster" order of sustained force.

If you start with a much higher force, like the case of diesels, you don't need to multiply it to high levels of speed to achieve a high power ratio... so the short times of acceleration... if you start with a less force, case of petrol, you need to achieve higher speeds of force multiplication to get to those levels of power... and though petrol engines can achieve higher levels of power "potentially" by having considerable more speed of force multiplication (now that diesels rev lower than 7K RPM), those higher levels of power compared with diesels is small or very small, and take considerable more TIME to achieve because petrol engines start with less force.

So its not that linear that troque = acceleration and power = speed... that is the scum oil war lords mantra that they want to indoctrinate.

Because this TIME TAKEN to achieve high orders of power, is the reason why max power of an engine is irrelevant... or less relevant, because from 0 to max power if it takes an eternity the engine its not good for racing.

Torque is much more relevant.