«Frozen» V8 in the Spotlight

The technical theme which prevails in 2007 Formula 1 concerns again engines. Certainly not in the most traditional terms, bound to advanced research and progress, as it has happened during a century of high-level competitions, but merely in order to correctly analyze the performances of race-cars during the whole 2007 season, after an epochal turning point.
We have passed from a contest which was excessively influenced by the characteristics of tyres (in view of the maximal obtainable adherence, with such a wild escalation that even the safety in the races has been undermined), to a confrontation with unified tyres, race by race, tyres which come from a unique, not free supplying. This situation leads back the analysis of performances to the usual components of engine and chassis. The better you value the former, the more easily is the survey about the latter, which includes also complex aerodynamic features.

A good knowledge of  this matter begins by noticing that Fia, after introducing the engine of 2,400 cm³ in 2006, with a series of rules to make it asymptotic, even decided to “freeze” it, with an absurd homologation, for the next four years, and to limit it, from 2007, at 19,000 rpm, under the pretext of cutting costs and saving all the constructors engaged.
An overall view of the problem allows us to state that the worst restrictions in the whole history have been imposed: the number and the disposition of the cylinders (8 arranged in a 90° configuration); the cylinder bore fixed at 98 mm; the cylinder spacing at 106,5 mm; the crankshaft centreline at 58 mm above the prescribed reference plane; the centre of gravity at 165 mm above the same plane; the weight not lower than 95 kg, etc.

In order to verify the maximum output of these engines, we may follow two usual technical ways, as they have been minutely described in my newest treatise “From Aerodynamics to Power in Formula 1”, published by Giorgio Nada: either calculating the total drag of the car or using the formula of power itself. The former calculation, proposed here, is based on the data of 2006 (aerodynamic characteristics and top speeds have been recorded on the most meaningful tracks, Silverstone and Monza), in order to carry out the right comparison.
Here are the results:

As far as the second way is concerned, we remind that the formula of power, besides piston displacement, cylinder number and bore/stroke ratio (constant values, here), considers also these following important variables: average effective pressure pme [kg/cm²] and rotational speed n [revolutions, in thousands].
The shift from engines developed until 2005 (10 cylinders of 3,000 cm³) to those of 2006 has kept the same unitary piston displacement and, practically speaking, the same ratio between cylinder bore and stroke. For this reason we may value their functional characteristics with a constant and stabilized pme, using a very simplified formula, in which we only need to know the revolution number (expressed in thousands, for greater convenience).
Hence, with some approximation, the power Ne [Cv] of a 2006-2007 V8 engine, with a pme about 14,77 kg/cm², as we may find only in the most advanced engines, will be:

Ne = 39,365  n

Obviously, as far as the less “daring” production is concerned, for example the one of engines which are sold to another team, the calculation must be done with lower pme values (because of reliability) and unlikely higher than 14,0 kg/cm².
Therefore, it will be very interesting to calculate, from the first to the last Grand Prix of the season, the highest power levels which have been reached, simply on the grounds of information about the rotational speeds which come from phono-metric recordings, or from data gathered by the electronic control units of each car (by contract they must be granted to the organizers), as it is often shown in TV broadcasting.

For this purpose we have yet to consider only the maximum rotational speeds reached in the top gear, which coincide with the highest point on the power curve.
On the contrary, with lower gears we will have a so called “over-rev” (falling power output), in order to shift on the most favourable point of the curve, when time comes to engage the upper gear.
For instance, according to a precious secret revealed to me by doctor Mario Theissen, director of BMW, the best 2006 engine reached 19,000 rpm in the seventh gear, while in lower gears it marked rotational speeds between 19,400 and 19,600 rpm.

With the ceiling of 19,000 rpm, included in 2007 Technical Regulations, engineers  have been forced to move the point of highest power about 400-500 revs under the aforesaid limit, in order to arrange the best exploitation during the phase of acceleration or while certain turns are run through.
Practically speaking, engines with 19,000 rpm on both characteristic points cannot exist. For this reason, the calculation of maximum powers, regarding top 2007 Formula 1 engines (depending on how rotational speed changes, with the top gear engaged) might give the following results:

at  18,800 rpm   -   39,365  ×  18,8  =  740  Cv    

at  18,700 rpm   -   39,365  ×  18,7  =  736  Cv    

at  18,600 rpm   -   39,365  ×  18,6  =  732  Cv    

at  18,500 rpm   -   39,365  ×  18,5  =  728  Cv    

at  18,400 rpm   -   39,365  ×  18,4  =  724  Cv    

at  18,300 rpm   -   39,365  ×  18,3  =  720  Cv      

Hence, it is in theory a little but considerable regression, in comparison with the achievements of the past year. It is the price to pay in order to guarantee the quinquennial levelling law required by the obscurantist Fia.

Toyota Engine

Renault Engine

Mercedes Engine