War of the classes

Le Mans isn't just about winning the race overall - it comprises four main separate classes, each entrant fighting for the honours in their respective class, and the competition within each often as fierce as that for the overall victor. The prototype classes - LMP1 and LMP2 - are for cars specially developed for the track only, and the GTE classes - GTE-PRO and GTE-AM - are essentially road cars modified for the track.

For many years, in order to prevent excessive power development, the rule makers for Le Mans and almost every other motor race on the planet have restricted engine output by limiting the cubic capacity or the number of cylinders, by modifying the size of air restrictors or restricting turbo boost, thus limiting the amount of air (and thus fuel) which could be fed into the engine. From 2014 in the LMP1 category, these fundamentals will radically change in that the energy consumption of the engine becomes the key factor. There will be no more restrictions on engine size, cylinders or air restrictors, and turbo boost pressure limit is now 4 bar, compared to the previous limits of 2.8 bar for diesels and 2.5 bar for petrol.

In simple terms, the new regulations challenge entrants to make the best use of a prescribed amount of energy in order to cover the longest distance within a given time – such as 24 hours at Le Mans. Old hands among the fans remember that this concept is not really brand new: Already in the glorious days of Group C sportscar racing there was a regulation which limited energy consumption, everyone got an allowance of 2,140 litres of petrol for the whole of the 24h of Le Mans. Engine constructors had complete freedom, in those days Porsche raced a 6 cyl. flat 3.0 litre Turbo, Jaguar used 7.0 litre V12 normally-aspirated engines, the folks at Mercedes built a 5.0 Litre V8 Turbo and Mazda used a rotary engine. Despite these very different concepts the performance of the competitors was close to each other, competition was fierce and the races were interesting to watch.

However, in the Group C days there were no energy recovery systems around and diesel was only used for team trucks, so this rather simple approach worked fine. The new 2014 regs allow engine constructors once again to built what they want, but the usage of energy recovery systems is now mandatory for the factory teams and engery consumption (both electricity and fuel) will be measured on a per-lap basis. For cost reasons privateers will still be allowed to race non-hybrid powertrains, but those have a limit of 5.5 litre engine capacity.

As a consequence the LMP1 class has been sub-devided into LMP1-L (L = light, for privateers only) and LMP1-H (H = Hybrid, for factory teams and privateers). An energy chart shows the amount of energy allocated to each power train concept, whether it be diesel or petrol. Hybrid systems are prescribed in four different performance classes, and a maximum amount of energy is defined for each of these classes.

What this boils down to is that entrants must have optimum control of the car’s fuel consumption, be able to approach the permissible energy limit as closely as possible, and the drivers must exercise an efficient driving style. If the amount of energy available per lap is not fully consumed, it cannot be carried over to subsequent laps and will therefore be lost. Should the prescribed maximum levels be exceeded, the excess consumption must be compensated for within three laps, otherwise penalties like stop-and-go may be imposed.

So effectively, the manufacturer with the most efficient power train being driven by drivers with an efficient driving style will win the race.

All this will mean that on-board loggers and computers will constantly be monitoring the fuel flow and output of the energy recovery systems, and data will be sent real-time to ACO computer equipment which will flag any discrepancy to the stewards. Hopefully we will not experience more ‘safety car’ periods this year as the French attempt to resolve bugs in their computer systems during the race!!!

Todays constructors seem to have a very different view on what might be the best solution, so similar to the old Group C we will see a variety of extremely different engines: Toyota will use a 3.4 ltr. V8 normally aspirated petrol engine, Audi a 3.7 ltr. V6-Turbodiesel and once again Porsche will have smallest engine with a 2.0 Ltr. 4-cyl-Turbo petrol engine.

Other significant changes: for the first time since 1999, the maximum width of P1 cars has been reduced from 2 to 1.9 metres. The wheels are also significantly slimmer. The minimum weight of the cars has been reduced to 870 kg.

The seating position of the driver is now more upright, and their angle of forward vision has been enlarged, while cutouts at the rear ends of the fenders optimise lateral vision. Passive safety has also been improved in that the monocoque must cater for higher loads, and special exterior layers provide protection against the intrusion of sharp foreign objects. Wheel tethers help prevent wheels from separating from the suspension in accidents, and P1 cars will be equipped with crash-boxes to better absorb energy in rear-end shunts.

In the “small” prototype category LMP2, the rules essentially remain unchanged for 2014, allowing competitors to continue racing their existing chassis, however cars conforming to the 2014 specification can also be entered. Open protypes are still allowed in this class and manufacturers are discouraged – “The ACO do not wish to encourage the Manufacturers to invest in LMP2 in any developments which improve the performance of the cars. The main objectives for these cars must be reliability, safety and a low maintenance cost. “ Also the rules for the LMP2 engines remain unchanged, and for cost reasons, these need to be based on production engines.

These are cars built by manufacturers for sale on the open market: Engine sizes are limited to 5.5 litres for normally aspirated engines, and 4.0 litres for turbos. Fuel capacity is limited to 90 litres. These cars are based almost totally on the old GT2 specification, with a few minor changes (ie paddle shift systems allowed and display, push buttons and switches allowed on the steering wheel). Cars not homologated by a manufacturer will also be accepted if entered by tuners - subject to separate homologation criteria. All cars are limited to one evolution per year, to be made before the first race of the season. LMGTE is sub-divided into two separate classes:

LMGTE-PRO - designed more especially for professionals where up-to-date models are used as the basis for the race car.

LMGTE-AM - more for the 'amateur', where cars must be at least one year old and without further modification. This is designed to create a second-user market for GT cars. The crew is limited to only one professional driver.

The following overview page gives just the most basic facts, the exact regulations are very extensive with lots of technical stuff, e.g. numbers about the minimum of road cars produced for the GT classes, size of the wings and others. The complete rulebook can be downloaded from the www.lemans.org website. All figures mentioned are maximum values, except the car’s weight of course…

• Closed roof sports cars with room for 2 seats
• 4.65 m length, between 1.8 to 1.9 m width, 1.05 m height
• Engine size is free for LMP1-H, max 5.5 litres for LMP1-L
• 64.4 litres fuel tank for petrol engines, 53.3 litres for diesel
• Headlights with white beam
• 16” wheel width, 28.5” diameter
• Race numbers in white digits on red background
• Bronze drivers are not accepted.

• Open or closed roof sports cars with room for 2 seats
• Production based engines: 5.0 ltr. atmo engine (max 8 cyl) or 3.2 ltr. Turbo (max. 6 cyl)
• 4.65 m length, 2.00 m width, 1.03 m height (or 1.05 for 2014-spec cars)
• 900 kg minimum weight
• 75 litres fuel tank
• Headlights with white beam
• 14” wheel width, 28” diameter
• Race numbers in white digits on blue background
• Must include a minimum of one Silver or Bronze driver

• “Professional” GTE sports cars
• Minimum weight 1245Kg
• 4.8m length, 2.00 m width
• 5.5 ltr. atmo engine or 4 ltr. Turbo
• 90 litres fuel tank
• Headlights with yellow beam
• 14” wheel width, 28” diameter
• Carbon brake discs
• Race numbers in white digits on green background
• The driver line up is free

• “Amateur” GTE sports cars
• Specification same as GTE-PRO
• The car must be at least one year old
• Race numbers in white digits on orange background
• At least one bronze and one silver or bronze rated driver in the team, only one professional driver from Platinum or Gold class

In 2007 the A.C.O. introduced the “leader lights” system. Each car must have 3 LED lights mounted on both sides; these lights have different colours for each class:

• LMP1: red lights
• LMP2: blue lights
• LMGTE-PRO: green lights
• LMGTE-AM: yellow lights

The leading car of each class will show one light switched on, the second place car two lights, the third place car 3 lights; if no lights are burning then the car is fourth or further down the order. These “Leader Lights” will help trackside spectators to follow the progress of the race, especially at night or in poor visibility. This system was developed and first introduced by the organizers of the American Le Mans Series in 2002 with the original idea coming from an American race fan. It reloads at the timing line so it is basically the previous lap position that one is viewing.