right i admit that i don’t know much about the real thing (am playing a computer game with le mans cars in it).
why is it that some of the fastest ones i.e audi R8 e.t.c have an open cockpit,whereas others like the bentley speed 8 are fully enclosed?
i would have thought that all the top spec prototypes would be fully enclosed (for aerodynamics e.t.c)
also why aren’t they all central driving position (like the mclaren f1) either?

Depends on a number of factors. Open top cars allow driver swaps to be carried out quicker and are better for driver extraction in the event of a big shunt. I don’t think there is a huge amount of difference with the aero bearing in mind that drag is a function of the frontal area of the car.. Not sure why the driver isn’t in the middle though but I think they might be in the closed cockpit cars.

The cars compete in different classes:

http://www.carmagazine.co.uk/News/Search-Results/Motor-show–events/Other-shows/Le-Mans-24-hour-race-2010-CAR-Magazines-guide/Le-Mans-24-hour-race-2010-the-classes/

Driver isn’t in the middle to aid packaging and weight balance. They may put the fuel tank up in the middle to minimise variable weight distribution (variable mass kept at the centre of car means turning and acceleration/decel don’t change unevenly as fuel load drops). Not seen too many off-centre drivers though.

Cockpit depends on rules and whether the designer felt the difference was sufficient to warrant the extra weight and complexity of needing a window clearing system. Speed is a function of a thousand variables, not just aero.

ah i see!thanks everyone 🙂

The main thing is if it’d not a French team, car or driver they mess with the rules until they get the ultimate. That is a French team, with a French Car and 3 French Drivers winning.
They nearly managed it last year but those pesky Germans screwed it up for them. A bit like the Euro really.

From Wikipedia…

Both classes allow open or closed-cockpit designs (closed car must have a windscreen, a roof and doors on each side). New for 2011, all closed-cockpit cars must have fins on the rear bodywork to prevent them from rolling over in the air during crashes. Although a passenger seat is not used, cars have to be designed to carry two people. The empty area of the cockpit is therefore usually used to hold electronic devices and cooling equipment.

I think there’s pro’s and con’s for each, hence why you’ve got some open cars and some closed cars. Back in the days of the late 80’s and early 90’s, when the cars had mega horsepower and the Mulsanne straight was uninterrupted by Chicanes, cars used to top 250mph. These days they’ve got little more than half the horsepower, so I don’t think the full benefits of an enclosed canopy (one assumes better aerodynamics, but it might not be that simple) are quite so prevalent.

Closed canopies have the disadvantage of needing to be air conditioned to keep the driver cool (saps power, adds weight, decreases efficiency), they’re more complex when it comes to driver change time, and open canopies seem to work ok for F1 cars doing predominantly speeds up to 200mph still.

It’s an odd one though, as over the last decade or so, I’d say the open/closed canopy debate is far less important than the diesel Vs petrol debate. That said, Audi has just switched to an enclosed cockpit on its latest car, having stuck with open cockpits for the past 12 years.

IMO, I think the open cockpits make more sense, for most of the LMP races, where they typically race for only 4hrs or so with one driver change. Closed canopies have almost always been designed purely with the LeMans 24hr race win in mind I think.

The cars compete in different classes:

http://www.carmagazine.co.uk/News/Search-Results/Motor-show–events/Other-shows/Le-Mans-24-hour-race-2010-CAR-Magazines-guide/Le-Mans-24-hour-race-2010-the-classes/

Open and closed cockpit cars compete in LMP1 class.

As others have said, it’s just two different approaches. An open cockpit car with a decently designed aero package will mean the driver is essentially invisible to the airflow over the body. A closed cockpit car with a well designed cockpit and trained crew will be no slower to get out of/in to than an open cockpit car. All swings and roundabouts really – totally depends on the overall package and team. Great racing though. Having the mix of classes really makes the races interesting. I spent two seasons working for an LMP1 team and am gutted I stoppe doing it – great fun at the time though!

just fiffering opinions on how to build a race car.
enclosed of couse means weight and larger roll cages etc windows and windscreen wipers demisters etc etc. but a consistant enviroment for the driver at a notoriously ‘weather prone track and how pleasant is it driving at night at 205mph in a hailstorm..
open cockpit in and out faster easy acess no driver comforts to provide.. you get wet and flies in your teeth and its either 30 degrees c or 5..
i’d opt for a convertable roof down 4 till early evening and then roll the hood up when it gets dark..

and go and see them

One year we stood at the guard-rail on the braking-marker for first chicane, the sheer noise/feel as the fast cars hit the brakes was incredible.