RetroRace gebruikt geen tracing- en blijvende cookies

RetroRace doesn't deploy tracing and persistent cookies
Since 2009

Keyword Search

Introduction to Sportscar Racing and Le Mans (page 2 of 2)

(continued from page 1)

On this page the following topics will be covered:

- sportscar classes and championships
- starting procedure
- driver changes
- Sportscar racing in practise
- Things worth knowing and tips

Sportscar classes

The global authority on the motor racing field, the FIA, in collaboration with the ACO (Automobile Club de l' Ouest - Le Mans, France) provides the classification of the various categories of sportscars in classes and issues in accordance therewith technical and sporting regulations.
As is the case with many other global agreements, in sportscar racing there are always countries and organizations that do not consider themself bound to these regulations. The result is that there exists a worldwide motley collection of sportscar series with private regulations or with regulations which partly follow the FIA/ACO ones. Therefore we confine ourselves to major sportscar championships/events, and if applicable, the deviations from FIA/ACO will be stated.

In order to avoid describing the classification and the requirements that the participants should meet becoming a dry enumeration, where possible, the subjects are placed in historic perspective, so that the connection to what was explained earlier in this article will be clear.

Sportscar classes and regulations in the World Endurance Championship (and the 24 Hours of Le Mans)

Prototypes are driven in two classes, each of which are divided into two subclasses:


Example of a LMP1-H prototype

  • Le Mans Prototype (LMP); these sportscars (purpose built for racing) are divided into subclasses LMP1 and LMP2.

Broadly it can be stated that the LMP1 class is the domain of the major car manufacturers and teams which are supported by the automotive industry, while the LMP2 class is mostly aimed at private entrants. Both prototype classes have to meet requirements regarding the type of coach-work and the means of propulsion. The LMP1 class is divided into prototypes equipped with classic petrol engines (LMP1) and prototypes equipped with hybrid drive (LMP1-H). Without exaggeration it can be postulated that the LMP1-H class harbors the summit of modern automotive engineering.

The LMP1-H class uses hybrid technology (fuel engine combined with accumulators and electric motors and/or storage plus drive through a flywheel). In order to generate energy for additional propulsion these cars use Energy Recovery Systems (ERS). These can for instance recover energy during braking (kinetic energy) and save it as electricity in a battery or capacitor. Another possibility for the storage of kinetic energy is the setting in motion of a (heavy) flywheel, of which the motion at a later time can be used again for propulsion. In addition, excess heat (thermal energy) can be drawn from the turbos and the exhaust, which is then transformed into electricity and temporarily stored.

this energy derived from ERS systems can,
when needed
(for example, when accelerating after a bend), be supplied to powerful electric motors which at the LMP1-H cars (in most cases) are part of the drivetrain. The whole of ERS and associated propulsion systems is called MGU (Motor Generator Unit).
While driving, the whole of ERS and MGU systems is controlled optimally by sophisticated electronic management systems. Clearly the collaboration and fine-tuning of these systems is a specialty, only reserved for brilliant electronics engineers and programmers. Again this is evidence that sportscar racing through gaining experience adds value in the development of vehicles for normal consumers.

Four degrees of ERS efficiency are distinguished, which are denoted in MegaJoules: 2MJ, 4MJ, 6MJ and 8MJ. After examination of the technical aspects of an LMP1-H car it is up to the FIA/ACO to determine in which MJ category it will reside. The 8MJ ERS-systems are providing the highest contribution to efficiency and therefore most of the extra horsepower on top of the power of the combustion engine. In order to ensure an equivalent competition level in spite of these differences, fuel consumption in the LMP1-H class is regulated by means of ultrasonic fuel meters (see below).

The traditional LMP1 class (without hybrid additions), which in fact is the continuation of the former LMP1 class of 2011 and earlier (although with adapted technical regulations), is ideally suited for (semi-professional) private teams. For propulsion only a fuel engine of up to 5500 ccm may be used.

The table below shows the basic specifications for the propulsion system of the LMP1 prototypes. There are also additional requirements to the various drive components (these are found in the technical regulations which are issued by the FIA before the start of each new season).

Basic specifications for LMP1 engines and energy recovery systems (2017)
Type of combustion engine
Intake restrictor Max. capacity (cm3)
Number of cylinders
None 4-stroke (Petrol or Diesel)
Atmospheric or pressurized intake (compressor) Ultrasonic fuel flow meter 5500
Max. 2 ERS systems per vehicle.
  Classification into one of four MJ categories by FIA/ACO
4-stroke (Petrol or Diesel) Atmospheric or pressurized intake (compressor) Ultrasonic fuel flow meter Free

* ERS = Energy Recovery System
= Motor Generator Unit

Further explanation of LMP engine technology

In making the choice by the manufacturer for the type of engine to be used (atmospheric or compressor supply), a number of considerations do apply in order to obtain a most favorable power/weight ratio within the terms of the technical regulations.

If atmospheric supply is selected, it would be obvious to make use of the maximum possible engine capacity permitted by the rules (5500 cm3), as this gives the most power at the maximum allowable fuel flow. The disadvantage, however, is that such an engine is large in size and weight.
The first property allows for less constructive freedom in the development of the chassis (the engine after all, needs a lot of space), while because of the second property a portion of the power is lost in compensating for the excess weight relative to a smaller engine.
Also it will be more difficult to remain close to the minimum required weight of the complete vehicle. However, a benefit is that the reliability of an atmospheric fed engine will be larger due to the fact that pressures occurring (and in connection thereto, the resulting temperatures) are lower than the pressures in an engine fed by a compressor. Moreover, the total cost will be lower (an important argument for teams that are not backed by a major automaker).

Due to the fact that a turbo-powered engine can deliver more power than an atmospheric engine with similar capacity, it can do with less capacity (eg. 2500 cm3) and less cylinders. This, of course, results in an engine which is lighter and smaller in size. It should however not be forgotten, that for example two turbochargers together with intercoolers also take room and add weight. In addition, in this case it must be kept into the bargain that the complexity of the management systems used with turbo-engines will be larger than with atmospheric fed engines (especially in combination with ERS/MGU).

On balance, today the advantages (as a result of the advancing techniques) usually fall in favor of engines equipped with turbo-compressors. Toyota, for example, switched from atmospheric to turbo engines for its 2016 LMP-H prototypes. While turbocharged engines are allowed in the LMP1 class (without hybrid systems hence), teams in this class will because of cost and reliability reasons often opt for an atmospheric engine.

Ultrasonic fuel flow meters explained:

Example of an ultrasonic fuel flow meter

The ultrasonic fuel flow meters (see illustration above) were introduced in 2014, simultaneously with Formula 1. These electronic meters in combination with real-time wireless transmission of the car's fuel consumption to the competition organizers make it possible to simplify the regulations in respect of fuel engines used in the LMP1 class, since with combustion engines it is no longer necessary to prescribe, eg. the number of cylinders or maximum engine power. Instead a predetermined quantity of fuel per unit of time and a minimum vehicle weight are keeping the matter in hand, allowing freedom for sportscar prototype manufacturers to design alternative engine technologies.

Assigning and monitoring of the fuel consumption gives the regulatory organizations the possibility of creating a level playing field between the mutual classes.
Use is made of three arithmetic allocation formulae (K Technology Factor, Fuel Technology Factor AV en Fuel Technology Factor Pmax).
Well before the start of a new racing season the values established at that time will be communicated to the manufacturers. These must then ensure that the electronic management systems in their cars are set up in such a way in that the fuel consumption at all times will remain within the standards (that this is no easy task, showed the example found in 2015 during the WEC race at the Nurburgring in Germany: one of the LMP1-H Porsches was receiving a stop-and-go penalty twice for a fuel flow found to be too high).

This jump to more constructive freedom once more revives the 'drive' from which endurance racing originated: the continuous improvement of transport in favor of new generations of motorists.


As stated earlier the LMP2 class is the main area of the private teams. It can be seen as a stepping stone to the bigger work: LMP1.
Up to 2017 fuel engines were permitted, whose engine blocks had to be derived from serial production (touringcar or sportscar). The engine capacity was set at 5000 cc without turbocharger and 3200 cc turbocharged. Certain race technical modifications (on eg. the cylinder heads) were allowed. Back then also a price ceiling for the chassis was already in place. As a result amateur teams could take part in this class at (relatively) affordable budget.

Under the previous specification, which was in force from 2011 until 2016, the LMP2 class has experienced a positive development, especially in Europe. However, because (despite all precautions), particular in the LMP2 engine area, costs ever continued to increase (even during the financial crisis around the beginning of the second decade of this century), the regulators (FIA and ACO) felt that new regulations would be necessary. Moreover, FIA and ACO felt with the growing popularity of sportscar racing in Asia and elsewhere, that the new regulations along with the WEC and the European Le Mans Series also should focus on other important international racing series such as the USCC.

In 2015 this led to the drafting of new regulations for the LMP2 class, which were shaped by the FIA/ACO together with the IMSA organization in America and the Asian partners of the ACO. The new LMP2 regulations came into force in early 2017 (the Asian Le Mans Series did receive 2 years delay because of the composition of their grids).

Highlights of the 2017 LMP2 specification are:

  • only four chassis suppliers are admitted and they are subject to a price ceiling for the entire chassis and also for spare parts.

  • only one engine type and supplier is permitted. The engine must be an atmospheric V8 with a maximum capacity of 5 litres, or a pressure fed (turbo) V6 of up to 3200 cc. The engine supplier must meet strict requirements regarding the cost of the entire unit, as well as the spare parts and the necessary revision cycles.

  • there is only one approved supplier for the electronic management systems and its components must meet the specific requirements of the FIA/ACO.

After several chassis suppliers had registered in 2015/2016, four manufacturers have passed the certification process of the FIA/ACO: Dallara (Italy/USA), Onroak Automotive (France), Oreca (France/USA) and Riley Technologies/Multimatic (USA/Canada/UK).

More information regarding these LMP2 chassis manufacturers:

Dallara, based in Varano, in the Emilia-Romagna region of Italy, is a familiar face in the racing world. They provide among others IndyCar single-seaters and sports prototypes. In the first decade of this century Dallara supplied the cars of the former A1GP series and in the first years of Audi in endurance racing they delivered the necessary chassis to the German brand.

Onroak, known for the Ligier brand has a good reputation in the field of manufacturing prototype sportscars. The French company has offices in Le Mans and Magny Cours, plus agencies in the US and Asia.

Oreca, led by the passionate CEO Hugues de Chaunac, has French offices in Signes and Magny Cours and agencies in the US and in Hong Kong. In past decades they were mainly active in remodeling and modifying cars for rally- and racing use. The company also has a particularly good reputation in the field of managing racing teams. In 2009 Oreca began manufacturing FLM (Formula Le Mans) prototypes.
This yielded no success in Europe, but all the more in the US when the American Le Mans Series was expanded to include a separate LMPC class. Since 2011 Oreca is also building LMP2 prototypes.

Riley Technologies/Multimatic is a North American manufacturer of racing cars. The headquarters is located in Mooresville, NC.
They are best known for the production of Daytona Prototypes (DP), but also the conversion and management of GT cars for racing is a specialty of this company; an example was the SRT Dodge Viper which competed in the American Le Mans Series from 2012 to 2014.
A partnership with the Canadian automotive supplier Multimatic Inc. provided Riley Technologies in 2016 access to the more than 50 years experience of the famous English Lola brand, which went bankrupt in 2012 and was acquired by the Canadian/American combination Multimatic/Haas. Riley Technologies/MultiMatic currently produces both LMP2 and LMP3 prototypes, as well as so-called DPi prototypes (see below at the USCC).

The LMP2 Powerplant

gibson lmp2 engine

Gibson GK428 engine

As an engine supplier for the LMP2 prototypes Gibson Technology from the UK (formerly known as Zytec) was chosen.
The Gibson GK428 V8 engine, measuring a displacement of 4200cc, was shown to the motorsport press in June 2016, on the eve of the 24-hours race in Le Mans. This LMP2 engine is the only one allowed to use in the ELMS and in the WEC from 2017, and delivers 600 HP according to the manufacturer. It is also known that Cosworth (UK) will supply the electronic management systems.

It was agreed that the Asian Le Mans Series will make the Gibson engine compulsory just from 2019.
Regarding the United Sportscar Championship (USCC) in the US, IMSA implements derogating rules concerning the engines and the car bodies (this will be covered at the USCC part below).
In the US for the LMP2 chassis the same regulations as elsewhere are in force. This is done to allow for American teams to participate in FIA/ACO sanctioned events (the engine however, will then have to be replaced with the standard Gibson).

Just as with the LMP1 class the LMP2 prototypes must meet in addition to the basic specifications to various supplementary requirements.
Due to the relatively low cost of LMP2 with respect to the LMP1 class the number of LMP2 teams increased considerably in recent years, which has fueled a fierce competition on the tracks.

Coachwork and chassis

The car body of the Le Mans Prototypes is regulatory largely free, except for the requirement that the body must cover the wheels, and a number of technical and aerodynamic requirements (including a mandatory tail fin for stability at high speeds, and holes in the fenders above the wheels to prevent exessieve downforce). This means that amongst the LMP cars several notable bodyshapes are to be admired.
The bodywork and aerodynamics of the LMP prototypes have to meet requirements with respect to dimensions, tank capacity and weight. The wheelbase (distance between front and rear axles) is free, however, details concerning the dimensions are too diverse and extensive to cover here (see the technical regulations for the relevant class on the FIA website).
The following table shows the main values for length, width, weight and fuel capacity (season in 2016).

Basic specifications LMP chassis/coachwork (2017)
Prototype class Max. length overall Width overall Max. tank capacity (petrol engines)
Max. tank capacity (diesel engines) Min. weight (incl. engine)
LMP1 4,65 m
between 1,80 and 1,90 m
67,4 Litres
53,7 Litres 855 Kg
LMP1-H 4,65 m
between 1,80 and 1,90 m 62,5 Litres
49,9 Litres 875 Kg
LMP2 4,75 m
1,90 m max.
75,0 Litres
N/A 930 Kg


With the advent of the WEC and the introduction of new environmentally friendly technologies, the allocation between conventionally powered cars and those with hybrid drive is changing steadily. In 2012, roughly half of the LMP1 prototypes were equipped with hybrid drive.
In 2016 the number of LMP1-H cars had reached a historical high, but by the departure of Audi from endurance racing and the reluctance of other manufacturers to participate in this costly branch of motorsport, this will be probably less from 2017. However, nothing in the rapidly evolving world of endurance racing is definitive, a year later the distribution may be different again.

Developments are going so rapid lately that further explanation in detail will carry the risk of being no longer valid in the short term. For details we refer to special sites that focus on the accessibility of the technique of (among others) sportscar prototypes. Wellknown sites in this respect are for instance Mulsanne's Corner , Gurneyflap and the Italian Pan Nullo blog.
So far the LMP prototypes.


Example of a LM GTE sportscar

  • Le Mans Grand Touring Endurance (LM GTE); this class for customized commercially available sports cars is divided into the subclasses GTE-Pro and GTE-Am.

Starting with the WEC in 2012, the existing GT1 class was abandoned, while the GT2 class virtually stayed. This class however was renamed to LM GTE and divided in GTE-Pro and GTE-Am. Was GT1 formerly the pinnacle of GT's, now it is the GTE-Pro class (herein we can find mainly teams with official factory support). The GTE-Am class on the other hand is intended specifically for amateurs like gentlemen drivers and runners-up. For participation in both classes the FIA places demands on the experience level of the drivers. In the -Am class must, for example, at least one of the drivers on the vehicle have reached the level 'Bronze' or 'Silver' (this refers to the experience level of the driver; who wants to know more can examine the 'WEC Sporting Regulations' on the FIA website). In this way it is prevented that a team of ill-prepared participants will appear at the starting grid.

Like the prototypes both GTE classes must also meet regulatory requirements regarding the body and the power train (currently only petrol engines are allowed, but that will possibly change in the future). Furthermore, a certain number (to be determined by the FIA/ACO) of these commercially available cars, being of the type to be used, have to be built and homologated before they may take part in races.

The engines may be customized for race use according to rules mentioned in the respective technical regulations and must at minimum meet the following basic specifications for atmospheric fed and turbo fed engines (similar to -Pro and -Am):

Basic specifications LM GTE engines (2016/17)
Engine type Cylinder block
Intake restrictor Max. capacity (cm3) Number of cylinders
4-stroke petrol, using atmospheric air intake Production block from original car series Air restrictor(s) in intake- manifold 5500 Original
4-stroke petrol, using pressurized intake (turbo compressor)** Production block from original car series Air restrictor(s) in intake- manifold 4000 Original

** a compressor equipped engine may only be used if the original commercially available car is also delivered with it.

Basic specifications LM GTE chassis/coachwork (2016/17)
Max. length overall Max. width overall
Max. tank capacity Minimum weight
4,80 m 2,05 m
90 Litres
1245 Kg

Other requirements (all classes)

In addition to requirements for the propulsion and the bodywork, the FIA/ACO organization demands all classes to meet additional requirements for a variety of technical and safety features on the cars. Furthermore, there are regulations that govern the sportsmanlike conduct in racing events. The regulations are adjusted annually to the state of technology and the safety requirements. In this way, the principles of Endurance racing (sportive competition and technical progress) are maintained within the safest possible setting.
The regulations are published on the website of the FIA (browse to: Sports > Regulations > FIA World Endurance Championship). The documents are bilingual (French left column, right column in English).

A special guest

Since the beginning of the Le Mans 24-hour race in 1923, the ACO is maintaining a reputation in facilitating new technical developments. Therefore, the ACO almost every year provides the possibility to register for the last place on the grid for a team that wants to try new techniques. Participation in this particular class is always non-competitive. Thus, both in 1963 and in 1965 a gasturbine-powered BRM prototype has participated.

Decades since no candidate had presented itself for this special place, but in 2012 there suddenly was the 'Delta Wing', a revolutionary prototype designed and built by a group of American motorsports enthusiasts (supported by former F1 driver Dan Gurney). It exhibited a delta wing -like shape (narrow front and wide rear). The car was propelled by a four cylinder Nissan turbo engine of 2 litres capacity. Unfortunately, the Delta Wing crashed after 75 laps beyond repair. In the short time it was on the course, it had however proved that it could get along in terms of lap times with the LMP2 cars. Incidentally, a further developed version of the Delta Wing prototype has participated until 2016 in the United Sportscar Championship in America (see below).

In 2014 a 'ZEOD' (Zero Emissions On Demand) electric powered prototype developed by Nissan received a place in the 'Garage 56' (as the pit box for experimental vehicles is called). This ZEOD Racing Car did have a small gasoline engine on board, but it charged just the batteries and was not connected to the drivetrain of the car. Unfortunately the Nissan ZEOD RC had to retire early, but fortunately the speed record for electric cars on a lap could still be secured.

In 2015, a prototype powered by hydrogen was announced to do the honors of Garage 56, but unfortunately the manufacturer had to drop out due to lack of development time.

In 2016, this special place was happily filled again. This time with a specially adapted Morgan LMP2 car for the Frenchman Frederic Sausset. The special thing about this entry was the fact that Frederic's arms and legs were partially amputated due to a severe infection.
With lots of willpower he managed to control the car by means special prostheses and controls designed by Onroak Automotive. It was therefore very special that Frederic and his teammates were able to occupy 38th place overall at the finish of the race. Click here to read more about this remarkable performance.

What ever happens however, again every year it is a surprise whether 'Garage 56' will be filled and what particular type of vehicle it will be.

Sportscar classes and regulations in the European Le Mans Series (ELMS)

As of 2017, the ELMS has the following format of classes: LMP2, LMP3, LM GTE-Am.

  • LMP2 prototype:

LMP2 prototypes in the ELMS must meet to the regulations that apply to the WEC. In 2017 a new regulation came into force. For details, see the explanation for the LMP2 class of the WEC (above).

  • LMP3 prototype (introduced in 2015):
    lmp3 silhouette

    Example of a LMP3 prototype

The in 2009 introduced LMPC prototypes, which were intended for novice teams, disappeared in 2014 because the development of these cars did stop. In their place the LMP3 prototype class was introduced. The LMP3 class is like the former LMPC class meant to serve as a training ground for future professionals (both drivers and teams). Because it is a true junior class, these prototypes may not participate in the World Endurance Championship (WEC). The ELMS is therefore their natural habitat, but because of the favorable cost basis these small prototypes can as well be encountered in other sportscar championships.

With the intention of keeping the class as cheap as possible, the production of chassis is authorized only for a limited number of suppliers (6 in 2017) and a price cap is being applied. Only fully equal engines from one manufacturer may be used (Nissan V8, delivering max. 420 hp).
The LMP3 regulations can be found on the ELMS website (under Presentation> Regulations).

  • LM GTE-Am production sportscars:

In the ELMS only one GT class exists: LM GTE-Am (hence ELMS has no -Pro class).
This GTE-Am class is a beginner class (like the LMP3 class at the prototypes), but in this case for GT cars. GTE-Am technical regulations in ELMS are equal to those in the WEC, only with the restriction that the cars must be at least one year old. This way costs are held down, as the cars are not allowed to be upgraded to the latest (WEC) technical standards. More information can be found on the ELMS website.
Interesting knowledge: before 2016 also GT cars authorized under the 'Porsche Super Cup' specification were admitted, but since there were barely any participants this category was dropped.

Sportscar classes and regulations in the United SportsCar Championship (USCC)

As of 2014, the merger of ALMS and Grand-Am into the United SportsCar Racing organization (USCR) became a reality. From that moment on the United SportsCar Championship (USCC) has become the most important sportscar racing championship in North America.
Because the USCC is highly dependent on sponsorship, the championship usually is being named after the main sponsor (for 2017 the 'Weathertech' firm is recruited).

The USCC has two sportscar classes:

  • Prototypes, divided into P and PC.

In the P class only prototypes are admitted and it consists of two distinct groups:

- Pro, consisting of LMP2 prototypes according to the FIA/ACO specification and DPi prototypes according to IMSA specification

- Pro-am, included herein are the Prototype Challenge (PC) vehicles

Taking a closer look at the IMSA P-class prototypes

LMP2 prototypes are no strangers in American sportscar racing, they already had a permanent place in the American Le Mans Series (1999-2014), and this is continuing in the current USCC. As previously mentioned, the USCR organization has had a substantial contribution in the realization of the new FIA/ACO LMP2 regulations, which were introduced in 2017. Logically the USCC LMP2 prototypes must meet these requirements.

DPi prototypes in the Pro class are a typical American phenomenon. They are in fact the successors of the so-called. 'Daytona Prototypes' (DP) from the former Grand-Am series. Unlike the former DP's (which were very different from the usual sportscar shape), the chassis and bodywork of the DPi prototypes are based on those of the LMP2 class. However, the requirements that IMSA imposes on the car bodies are different from the customary LMP2 prototypes. In order to accommodate commercial parties (read sponsors), the front of the body may in fact be customized in such a way that it resembles the front of a car model available in the US market.

The motorisation of the DPi's constitutes an even bigger difference with that of their LMP2 counterparts. It is known that Americans have a special liking for large engines (who doesn't know the saying 'there's no substitute for cubic inches'?). It may therefore be unsurprising that besides the familiar 4.2-litres V8 Gibson also American V8 engines of up to 6.2 litres may be applied. The engine range in the P class is furthermore knowing 4 and 6 cylinder turbo engines (more on the USCC website). Nevertheless the USCR organization thinks it can create a 'level playing field' through the 'Balance of Performance' (BoP) regulation. This boils down in such a way that participants who have proved being too fast will be slowed using technical measures (eg. extra ballast and/or restriction of air supply to the engine). It is clear that the 2017 season will show interesting developments in this regard.

PC prototypes (in the Pro-Am class) are a regular feature in IMSA sportscar racing since 2009. Originally these prototypes (which were launched in that year by the French Oreca company) were intended to take part in Europe to the 'Formula Le Mans' (FLM) championship promoted by the ACO. However, in the European Le Mans Series this class never took off.
This went a lot better in North America, where in the American Le Mans Series in 2009 was a need for suitable prototypes to populate a runner-up class. So the former FLM prototypes got a special place in in the ALMS Prototype Challenge (PC) class, which has also continued from 2015 when ALMS and Grand-Am merged in the USCR organization.

Although at the time of writing not yet definitively decided, it is expected that the PC prototypes will eventually be succeeded by the more modern LMP3 prototypes. Meanwhile, there is already at least one US manufacturer that produces LMP3 prototypes (Riley/MultiMatic).

  • GTs, divided into GTLM (GT Le Mans) and GTD (GT Daytona).

GTLM: this class, such as addition 'LM' indicates, houses Le Mans eligible Grand Turismo sportscars which satisfy the FIA/WEC GTE-Pro regulations, allowing them to be used internationally (American GTLM teams for instance are virtually each year a guest at the Le Mans 24 hour race in France). At the merger in 2015 between ALMS and Grand-Am, the former GT2 (ALMS) and GT (Grand-Am) classes were put together in the GTLM class. Teams in this class are usually supported by major car brands.

GTD: the suffix 'D' stands for 'Daytona' and this indicates that this class essentially was derived from the former Grand-Am Series.
When ALMS/Grand-Am merged in 2015, the former GTC (ALMS) and GX (Grand-Am) classes were put together and they now constitute the GTD class, which is basically meant for amateurs, but limited factory support is allowed. Because GTD sportscars do not meet the FIA/WEC GTE-Am regulations, they can not be deployed in FIA/ACO-sanctioned events.

Notes to the USCC championship:
Despite the sometimes difficult economic conditions there are fortunately still American teams who find it an honor to participate in both the USCC and the WEC. Clearly it mainly concerns participants in the LMP2 and GTLM classes. Most of these teams will participate in selected races only (in the WEC obviously the 24 Hours of Le Mans).

Sportscar classes and regulations in the Asian Le Mans Series


The regulations and the classification of the prototypes in the Asian Le Mans Series are basically identical to those of the ELMS. Prototypes in the LMP2 and LMP3 classes are thus allowed. Because the sportscar racing in Asia only is in its infancy, the number of participants is still small (especially in the prototype classes), therefore the grid is usually completed with prototypes from the CN series (Group CN is a platform recognized by the FIA for small prototypes, equipped with a motorcycle engine up to 2000cc).


Unlike the ELMS the Asian Le Mans Series knows two GT classes: GT and GT-Am. The GT class consists of GTE, FIA GT3 and GT 300 Japan sportscars, while in the GT-Am class (not to be confused with the LM GTE-Am class in the ELMS) various sportscars from brands series such as the Lamborghini Super Trofeo, Porsche Carrera Cup, etc. participate.

For more detailed info on ASLMS classes and regulations see the ASLMS website.

Further facts worth knowing:

Action anytime, anywhere

Division in classes does guarantee lots of action on the track; other than is the case with single classes there will always be more overtaking because of speed differences between classes. Drivers in faster cars (e.g. prototypes) have to push their way through the field, even while battling with their own class contenders. In contrary of Formula 1 an endurance race seldom will look like a procession.

Smart viewing aids

It can be difficult (especially for beginning sportscar racing fans) distinguishing which cars belong to which classes and moreover, how it becomes clear which cars are on top of the field (certainly after pit-stops have taken place). Luckily easier distinguishing is achieved by a smart on-car position lighting system, called 'Leader lights', see picture below:


Position indicators - copyright ACO

The system comprises of three coloured lights placed one above another at both sides of the cars. Classes can be distinguised by colours:

Class Colour of position indicator
(same for number shield background)
LMP1 Red
LMP2 Blue
LMP3 Purple
GTE-Pro Green
GTE-Am Yellow

Car's position can be read as follows: first place in class - 1 light lit, second place - 2 lights lit, third place - all lights lit. In this manner the three forerunners of each class (except GTC) can easily be distinguised at any moment during the race. The lights are handled by race-control by means of the obligatory telemetry system in the cars.

A new development: at the end of 2015 in the American USCC series experiments were conducted with wireless-enabled LED digits, that are embedded in plastic stickers (a development of the Dutch company These designations have the advantage that the position of all participants (instead of only the first three) can be displayed. This system already has turned out so well that it is established as a standard by the USCC in 2016.

Next to the leader lights the GT cars must have yellow frontlights fitted (ACO sanctioned events only), enabling faster competitors to perceive slower cars when they enter a curve at night.

Spotters Guides

Especially for sportscar racing fans are so called 'Spotters Guides', issued by the American graphic designer Andy Blackmore. These Spotters Guides contain pictures of the participating cars, complete with start number and the names of the drivers involved. These guides are very useful for the overview during the race on the track. They are available on the website in digital form (.pdf or .jpg).

Starting procedure

An old custom of the 24 hours race was the famous 'Le Mans' starting procedure: the cars being lined up at the right side of the track and the drivers at the opposite side. When the French tricolore was waved all drivers took a sprint towards their cars, started the engine and drove away. This didn't pose any problem in vintage times, but around 1965 starting velocities had increased to an extent beyond responsibility: many competitors dind't even take time to fasten their seatbelts.

Jacky Ickx's action in 1969

In 1969 the six times Le Mans winning Belgian driver Jacky Ickx took the initiative in altering this behaviour; at the starting signal he coolly walked to his car and before starting he firmly secured his racing harness (you can watch this famous incident starting the above video by clicking on the small triangle). In the first lap it already became clear that he was right because of the lethal accident of Englishman John Woolfe (he indeed did not have his seatbelts fastened, but it is estimated that the accident also was brought about by instability of his car, an early Porsche 917). Later in the same race Ickx fellow countryman Willy Mairesse died in an accident as well. He too didn't wear safety belts. In order to avoid such tragedies the ACO decided that in future the 24 hours race would feature a rolling start, while wearing seatbelts was made obligatory on penalty of exclusion.

Driver changes and strategy

It seems an impossible mission driving the Le Mans 24 hours completely solo. Nevertheless the earlier mentioned Pierre Levegh (his real surname being Bouillin though) nearly succeeded, but while occupying first place, 90 minutes before the end of the race his Lago-Talbot ceased. Fortunately such irresponsable behaviour isn't possible anymore, safety in endurance racing being of great importance nowadays. That's why a team of drivers in races covering 12 hours or longer has to comprise a minimum of three persons. According to Le Mans regulations every driver is allowed to be in service for max. 4 hours during a 6 hours period, while each driver's activity may not extend over 14 hours.

Driver changes almost without exception are carried out during pitstops which have to be done for taking fuel and change tyres. As a result of the circumstance that tank capacity is fixed by regulations and fuel consumption varies between cars and classes, pitting strategy has become an important issue in winning an endurance race. An example of this is taking fresh tires only after two, or even three stints (one stint = track time between 2 tankstops) in order to save valuable time.
As a result of the long running time in endurance racing, maintenance virtually never seen in other autosport disciplines must be carried out (i.e. renewal of braking pads). Even time consuming repairs are carried out, because other teams too have a fair chance to run into trouble. While small repairs are allowed to be carried out in front of the pits, radical repairs must be carried out by putting the car on trollies and hauling it back into te garage. This being a regulatory safety measure.

Sportscar racing in practise

When you have arrived at this stage in the article, then there can be no misunderstanding in your interest about Sportscar racing. In case you never have visited a real life endurance event, it is strongly advised to do so. Inhabitants of northwestern Europe (with exception of Great Britain) will have to go abroad when aiming to attend endurance events bearing real international status. If you like to go to Le Mans, allright, you couldn't do better, but on the continent there are other possibilities: for instance at Spa Francorchamps (Belgium) or at the Nürburgring (Germany) nearly each year WEC and/or European Le Mans Series events are held. A good start initially would be watching an ELMS race on television (chances are that parts of WEC and/or ELMS events are broadcasted by Eurosport, information can be obtained here).

Endurance racing is offering great hospitality to visitors; you will expierience wide access to places (e.g. the paddock) which are mostly prohibited when visiting other autosport disciplines. Once having attended a real live endurance event, there is a great chance you ultimately would like to visit the Le Mans 24 hours race.

More information about the Le Mans 24 Hours race

Le Vingt Quatre Heures, as the French call it is not just any event. To begin with it is the largest one day long event in Europe and it has attracted for decades more than 220,000 visitors from all over the world. Then the fact that in 2015 the number of registered drivers was 168 (!) (coming from 29 different countries). You may be surprised about this big number, but this obviously relates to the fact that there are three drivers per car needed. It is remarkable however, that the Dutch public broadcaster is totally not paying attention to this grand sporting event (to which regularly Dutch drivers are participating).

The Le Mans 24 hours race of course represents the pinnacle of all endurance racing events organized annually. Well before the race is due, much discussion about the subject is going on in the internet forums (see menu Weblinks, section Forums + Blogs). Le Vingt Quatre Heures, as the French call it, can't be regarded as an average event. It all starts in the week preceding the race; at first the technical scrutineering of the cars ('le pesage') takes place. Other than one might expect this takes place on a square right in the center of the town. Always crowded but a joy to attend.
On wednesday evening free practise is carried out (featuring a session in the dark as well), while qualifying sessions are held on thursday evening. Because the circuit partially runs on public roads, these are closed during training sessions and on raceday. On friday no further training is allowed, enabling mechanics to carry out last service and adjustments to the cars. On friday afternoon the public is allowed a 'pitwalk' (sadly requiring an extra fee in recent years), during which the public can take a close watch at the teams and their cars. Finally on friday evening 'La Grande Parade' is held, starting in town at the cathedral and featuring a colourful procession of drivers (distributing promotional material, while seated in vintage cars), accompagnied by music and feminine beauty. Clicking on the picture below will offer a short impression.

The 2006 Grande Parade

On saturday the start of the race is at stake, originally at 4 o'clock in the afternoon, but nowadays the organisers are considering the evacuation of the roughly 250.000 spectators better than before. That's why the race is started at 15:00h exactly and evidently ending 24 hours later on sunday.
Compared with other multi-day events a visit to the 24 Hours of Le Mans is fairly affordable; especially when one realizes that a general week ticket (called 'Enceinte Generale Semaine') did cost 71 Euro's in 2013, and apart from giving access to the spectator areas on raceday, they are valid on training days as well. An exception being access to the grandstands, which need an extra fee at raceday. Once having experienced this event, it will be hard not returning again in future.


Things worth knowing and tips:

- much information about the Le mans 24 hours race can be found at the official Automobile Club de l'Ouest website (French, but there is an English section as well). They are doing profound advertising for ordering tickets in advance, but with exception of admission tickets for the grandstands, these can as well be obtained at the entrance gate without additional charge (virtually no qeueuing occurring).

- Le Mans is a lovely town and the historical center is surely worth visisting, making a short holiday a well considered possibility. One of the advantages is getting a better experience as the town is sparkling with activities.


The 24H monument in Le Mans center

- specially organized (coach)travels, admission tickets and accomodation often included, are offered in European countries. These are mostly reasonably priced, but such a journey can be very tiring. Alternatively you can travel to Le Mans yourself and look for accomodation on arrival. Using the sophisticated public transportation system your hotel and the circuit can be reached comfortably.

- for those who cannot afford staying at a hotel (or for those aiming to experience the special fan atmosphere), there are campings on the circuit's premises. A place has to be reserved well in advance however, and you'll have to take for granted a lot of noise (not only from the racing cars).

- not so young racing lovers who not neccesarily want to stay at the race at night (and maybe like a bit of sleep) do better by booking a hotel, rent a 'gîte' (cottage) or stay at a campsite well away from the circuit. Suitable campsites are located south of Le Mans. Unfortunately, the camping Municipal in Roézé sur Sarthe is closed, but luckily two alternatives remain: the relatively small 'Camping du Domaine du Houssay' in the village of Spay and the (larger) 'Camping Municipal Le Port' in La Suze-sur-Sarthe (see under 'Tourisme' on the site of the municipality). More detailed information about these (and other) campsites can be obtained with the help of the French camp site search
There are people however (notibly French) who like to visit the race during the dark hours only, just because of the special atmosphere.

- visitors arriving by car can park at the circuit, but one has to be aware of leaving the car at one of the immense (colour coded) parking lots from which there is no easy escape between times (this however is no issue on practisedays and moreover parking is free then). Although the organizer has much experience in evacuation of the spectators after the race, delays often are inevitable. A smart alternative (although not favoured by local authorities) could be searching a public parking lot in one of quarters next to the circuit. The distance to the circuit's entrance gate can easily be bridged using the modern tramway.

- most spectators obviously visit the start- finish area. There are however other interesting places where the public is allowed, for instance the 90 degree corner at the end of the Mulsanne straight or the sharp corner at the village of Arnage. Both sites can be reached from the main entrance gate, taking one of the shuttle busses.

RetroRace is hoping this introduction in the fenomenon of sportscar racing has aroused your interest. More information can be found in the 'Weblinks' menu (section 'Sportscar racing').
Back to Articles Menu