A Le Mans Prototype is the type of sports prototype race car used in the 24
Hours of Le Mans, FIA World Endurance Championship, United SportsCar
Championship, European Le Mans Series and Asian Le Mans Series. Le Mans
Prototypes were created by the Automobile Club de l'Ouest. The
technical requirements for an LMP include bodywork covering all mechanical
elements of the car. While not as fast as open-wheel Formula
One cars, LMPs are the fastest closed-wheel racing cars used in circuit
racing. Le Mans Prototypes are considered a class above
production-based grand tourer cars, which compete alongside them in sports
car racing. Modern LMP designs include hybrid cars
that use electric motors to assist acceleration.
Name variations Le Mans Prototypes have used various
names depending on the series in which they compete. The FIA's equivalent cars
were referred to as Sports Racers or Sports Racing Prototypes. The American
IMSA GT Championship termed their cars World Sports Cars', while the
short-lived United States Road Racing Championship used the classic Can-Am
name for their prototypes. Since 2004, most series have switched to referring
to these cars as Le Mans Prototypes. The American Le Mans Series, the successor
to the IMSA GT Championship and the predecessor of the TUDOR United
SportsCar Championship, officially referred to the cars simply as
Prototypes. An LMP is commonly referred to as a Le Mans car in the media.
History The first use of what would become Le
Mans Prototypes was at the 1992 24 Hours of Le Mans. In an attempt to increase
the number of entrants beyond the small field of Group C competitors that the
World Sportscar Championship had to offer, older Porsche 962s were allowed
entry in Category 3. To further increase the size of the field, small
open-cockpit race cars using production road car engines which were raced in
small national championships, were allowed in Category 4. Only three cars
were entered, with all failing to run more than a few hours.
However at the end of 1992, the World Sportscar Championship as well as the
All Japan Sports Prototype Championship collapsed, leaving the expensive Group C
prototypes little competition outside of Le Mans. With Group C being phased out,
the ACO chose to allow production-based race cars to enter for the first time in
many years, while at the same time creating the Le Mans Prototype class.
The cars continued to use the same formula as they had in 1992.
Later, ACO announced their intentions to completely replace the Group C cars with
Le Mans Prototypes in 1994. Two classes were created, with LMP1s running large
displacement custom-built engines that were usually turbocharged, and LMP2s
using the smaller displacement production-based engines. Both classes
were required to have open cockpits. At the same time, the IMSA GT Championship
announced the end of their closed cockpit GTP and Lights classes, deciding
as well to replace them with a single open-cockpit class of World Sports Cars
equivalent to LMP1. This formula continued up to 1996, with
many manufacturers embracing the LMP and WSC classes, including Ferrari, Porsche,
and Mazda. In 1997, the first European series based around Le Mans Prototypes
was launched, known as the "International Sports Racing Series".
Using classes similar to LMP1/WSC and LMP2, these cars were known as "SR1" and
"SR2" by the FIA. 1998 saw the creation of another series of Le Mans Prototypes,
with the new United States Road Racing Championship attempting to break away
from the IMSA GT Championship. To differ from IMSA'S WSC class, the USRRC named
their open-cockpit prototypes "Can-Am" in an attempt to resurrect the sportscar
championship of the 1970s. However the USRRC collapsed before the end of 1999,
with the series becoming the Rolex Sports Car Series who chose to use the
FIA's SR1 and SR2 formula instead. 1998 saw a great expansion for the ACO's
LMP classes. Following the cancellation of the IMSA GT Championship at the end
of 1998, the ACO allowed for the creation of the American Le Mans Series.
This series used the same class structure as the 24 Hours of Le Mans,
meaning it was the first championship to use the LMP name. At the same time, the
ACO greatly altered their LMP classes. The smaller LMP2 class were briefly
eliminated, while a new class of closed-cockpit prototypes were allowed
in, known as "LMGTP". These cars were evolutions of production-based road cars
that the ACO considered too advanced and too fast to fall under the GT class
regulations, forcing the ACO to promote them to prototypes.
In 2000, changes were made to the LMP regulations, as the ACO once again split
the open-cockpit LMP class. The two new classes became known as "LMP900" and
"LMP675", with the numbers denoting the minimum weight requirements for each
class. The LMP900s were to be more powerful and faster in top speed, but
also heavier and more cumbersome. The LMP675s were to be smaller and more
nimble, yet lack the top speed of the larger class. Both classes were intended
to be able to compete for overall wins. Audi, Chrysler, Cadillac, and Panoz
opted to use the LMP900 formula, while MG were the only major manufacturer to
attempt the LMP675 class. The LMGTP class also continued, with Bentley being
the only manufacturer to build a closed-cockpit prototype after the
regulation changes in 2000. Outside of Le Mans, the FIA's SR classes
suffered from these rule changes. The SR2 class no longer aligned perfectly
with the new LMP675 class, with the more powerful and durable racing engines that
were allowed there. The SR1 and LMP900 classes also did not use the same rules,
although engines were mostly similar. This meant that teams competing in the
newly renamed FIA Sportscar Championship required modifications to their cars to
be able to compete at Le Mans and in the new European Le Mans Series, a second
series split from the American Le Mans Series. With FIA Sportscar Championship
teams unwilling to modify their cars to run in the ELMS, that series was
canceled due to lack of participants. However the demand to race at Le Mans
eventually forced the FIA Sportscar Championship itself to be canceled in
2003, with most competitors choosing to comply with the ACO's regulations
instead of the FIA's. With the Rolex Sports Car Series also abandoning their
SR classes at the end of 2003 for their own unique Daytona Prototypes, this
meant that the ACO LMPs were the only open-cockpit prototypes left.
With the prototype classes now unified under the ACO's rules, the class
structure was once again reorganized. The LMP675 class was considered a
failure, due to the small engines lacking the reliability necessary to
compete for overall wins, regardless of any advantage they had with cornering
and weight. The LMGTP class was also considered redundant since the cars had
only minor rule differences from LMP900s. Thus, the classes were changed
to LMP1 and LMP2, with the top class once again being larger and more
powerful. However the smaller LMP2 class was now intended solely for privateers,
with major manufacturers encouraged to move to LMP1. This meant LMP2s were no
longer meant to run for overall race wins. Since the LMGTP class was
eliminated, both LMP1 and LMP2 were allowed to have either open- or
closed-cockpit designs. These new rules also added increased safety
requirements, including larger rollover hoops and aerodynamic plates attached to
the rear of the cars in order to prevent prototypes from becoming airborne in
accidents. The LMP1 and LMP2 classes continue to be
used at the 24 Hours of Le Mans and in the newer championships that were
created by the ACO: the Le Mans Series in 2004 and the Japan Le Mans Challenge
in 2006. In 2004, the ACO renamed LMP900 back to LMP1, and with this they limited
the rear wing to 1.9m and reduced the fuel tank capacity from 90L to 80L. This
was done in an effort to promote new hybrid LMP1 cars while putting more
restrictions on the aging LMP900 cars like the Audi R8. New safety measures
were also brought in, and prototypes were now required to have two rollover
bars instead of one. The final year that LMP900 chassis were allowed to be
entered was 2006. In 2009, LMP2 restrictors were brought
down from 45.5mm to 43.5mm. Technical regulations
The main technical regulations for LMP class cars are:
The fuel tank size and minimum weight for non-hybrid cars may get adjusted to
reduce the difference in performance between hybrid and non-hybrid cars.
There are no limits on the number of cylinders for any type of engine.
Bodywork is required to cover all mechanical elements of the car, so that
it cannot be visible when the car is viewed directly from the front, side, or
top. The LMP1 cars are generally the most
powerful, with faster straight-line speeds.
Only production-based engines are allowed in LMP2 with diesel engines
permitted from 2013 onwards. Biofuels, specifically petrol with 10%
ethanol and biodiesel, are allowed in both categories.
LMP2 allows both open- and closed-cockpit designs, while only
closed-cockpit design is allowed for LMP1 as it is much faster and for
safety. As of 2011, all 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 must be designed to carry two people. The empty area of the
cockpit is usually used to hold electronic devices and cooling
equipment. = Related classes=
LMP3 – A low-cost class intended for introducing young drivers and new teams
to endurance racing before they progress to the higher classes of prototype
racing, LMP2 and ultimately LMP1. LMP3 uses closed-cockpit chassis, which can
be built by any constructor, powered by a 5-litre normally-aspirated V8 Nissan
engine. The class will be raced from 2015.
LMPC – Le Mans Prototype Challenge. An earlier attempt at an entry level class,
introduced in 2009, this class consists of competitors running identical Oreca
FLM09 cars. As the cost of running an LMPC team was found to be comparable to
that for an LMP2 team, the class is expected to be replaced by the LMP3.
List of Le Mans Prototypes See also
Formula Le Mans Group C
GTP WSC
Daytona Prototype Group CN
Group 6 References
External links = Racing series=
Official website of the 24 Hours of Le Mans
American Le Mans Series European Le Mans Series
= LMP analysis= European Le Mans Series - Explanation of
LMP classes Mulsanne's Corner