States His Case
We’ll provide an opportunity for others to
state their views in due course (that’s how the internet works
– stage by stage), but this is what Henri Pescarolo has to
say today, October 23, with regard to the 2007 ACO regulations,
as regards equivalency between petrol and diesel-powered prototypes.
The bulk of
this page comprises Henri Pescarolo’s open letter on the subject,
but we’ve followed up with some additional comments, gathered
from him on the telephone today. Because this translation may not
be an absolutely correct one – some phrases make it very difficult
to infer the exact meaning, while others demand that a certain English
phrase is used – this Open Letter should not be copied
and pasted all over the internet: we at dsc can accept
responsibility for what appears here, but would ask that it isn’t
At the time of the 24 Hours of Le Mans 2006, the competitors
using petrol-powered engines had had all the time to note that the
equivalences defined by the ACO’s regulations were not correct.
The press had been making the same ‘noises’ and the
public had also understood it. However, some thought that it was
completely normal that the Audi Diesel is on average 3 to 4 seconds
faster on a complete circuit than the best of the cars propelled
by a gasoline engine. For them, this difference was due only to
the colossal difference in budget between one and the other.
have been carried out, by various engineering and design departments,
and all arrived at the same conclusion: that the Diesel engine was
heavily favoured. To have a full understanding, and wanting to be
careful, the ACO equipped all of the 24 Hour cars with of a system
of data acquisition recording all the parameters on a lap of the
circuit. These measurements were partly published at the end of
most significance is the first sector, in particular past the Tribunes,
because if the Audi is 0,544 seconds faster on the whole of the
sector, on the 398 meters of pure acceleration (past the pits),
it takes it 0,1395 second less to pass from 130 to 250 Km/h than
the best gasoline-powered car. Compared to the 9 600 meters of acceleration
in a straight line that the (whole) circuit comprises, that would
make 3,36 seconds in total, on one lap. That is rather close to
reality. A theoretical calculation makes it possible to evaluate
that with identical tires, this variation in acceleration is generated
by a difference in power of about 57 bhp. There too one is close
to the announced figures.
Let us look
at the second sector - Les Hunaudières – where the
Audi is 1,19 seconds faster. As the top speeds are (almost) identical,
325 against 326 Km/h, it must be that there is a difference in acceleration
in a straight line until the maximum speed is reached. The two chicanes
are taken at appreciably at the same speed.
sector, with the Audi 1,34 seconds faster, confirms the two preceding
analyses, but in the Porsche turns, it is more the torque than the
which brings an advantage. On the other hand the difference
between the best lap in the race of Audi and the best gasoline car
is completely significant: 4,4 seconds (3' 31' ' 211 against 3'
35' ' 656) is enormous, and remember that we are only at the beginning
of the development of the diesel engines!
study of partial times makes it possible to note than the advantage
in the corners, about 1,5 seconds, is not negligible, but is not
independent of the power available. Indeed for a higher power, with
an identical top speed, means aerodynamic choice is available, to
enable the best handling. However, you do not have to be a ‘university
technician’ to prove that in an application of the power to
weight ratio, a Diesel car developing 700 CV was going to accelerate
much more quickly, with identical weight, than a car gasoline having
only 640 CV!
statement published on last 13 July by the ACO was however clear:
"Only an advantage related to the performance of the engine
can lead us to take measures in order to reduce the performance".
Having seen the preceding figures, which highlight clearly this
advantage of the Diesel power, one could thus expect, and promises
had been made in this direction, that new equivalences were to be
applied for 2007.
showed the way in the American Le Mans Series. By withdrawing 65
kg from the weight of the gasoline-powered cars, it found a real
equality between the various competitors. The last races of the
season were enthralling, and finally if Audi continued to win, which
appears normal, it is while fighting until the end with equal weapons,
and that is completely new.
publication of the 24 Hours regulations for 2007 clearly shows that
the ACO chose to preserve a substantial advantage for the diesel
engines. However only the two manufacturers present in LMP1 can
have it. Is this chance? If this is not the case, it is serious.
Because that means that the ACO wishes that nobody can come to disturb
the play of the two large manufacturers. If they’re assisting
an eighth consecutive victory of the VAG Group at the next the 24
Hours of Le Mans without there being a real opposition, the ACO
will have to account for the return of the public and the media
however a glimmer of hope, a small concession was made: the capacity
of the diesel tanks was reduced by 9 liters so that all the cars
stop at the same time to refuel. This represents 0,7 seconds per
lap over the 24 hours, which is far from being sufficient. But it
is perhaps the sign which some are realizing, within the ACO, which
has a first duty, besides innovating in the technical field, to
institute a perfect equity and to harmonize the powers between the
various allowed power sources - diesel, gasoline or hybrid, whatever
is used. And then, as stipulated in its official statement in July
2006: "all the other elements of the car being built with the
same schedule of conditions, it thus rests with the manufacturers
to build the best car".
with respect to the lovers of the 24 Hours of Le Mans, and with
again, I hope, the support of the public, Pescarolo Sport will take
up this new challenge nevertheless. More justified than ever, the
local Sarthe stable will enter two new cars, with new aerodynamics,
firmly persuaded that even in the universe of the sport, sometimes
morals can triumph.
In conversation with Henri Pescarolo today, he made
it clear that “I wanted to explain the position using the
official figures relating to what actually happened during the race.
“The problem for the small teams and engine
manufacturers is that they were not invited to express their views
to the ACO. The small teams are afraid of losing their entries.
“But I am prepared to say what I think because
I already have two guaranteed entries for Le Mans next year, because
of our success at Le Mans and in the Le Mans Series.”
So do you think you can persuade the ACO to change
its regulations for next year, Henri?
“No, not for next year. They have decided
to have the smaller fuel tank (for the diesels) next year, but maybe
for 2008 it could be more.
“The President of the ACO, Monsieur Plassart,
is starting to realise that it is not good to do just what the big
manufacturers want. If we’re really strong, perhaps there
is a chance to do something for 2008.”
As above, we’ll
be presenting more sides to this story in due course. Henri Pescarolo
is to be admired for stating his views so openly.