Porsche 944 Turbo Cup Introduction
After the
successful introduction of the Porsche 944 Turbo (951/952) in the year
1985, Porsche started the development of a race car basing on the 951
which would then lead to the first one make race series in the history
of Porsche. The car and the Cup were called 944 Turbo Cup.
The cup cars
received a number of performance-enhancing modifications which were
implemented into the serial production with the 944 Turbo S.
The turbo cup
cars were undertaken a continuous optimization, power output was
increased from 220 bhp to 250 bhp and to 290 bhp for French cup cars.
The Turbo Cup was
carried out in Germany from 1986 to 1989 and in France from 1987 to
1990. While in 1990 in Germany the 944 Turbo Cup was taken over by the
964 Carrera Cup, the Turbo Cup in France was continued for one more
year and saw the ultimate evolution of these cars.
The below
information is referring to the French 944 Turbo Cup Cars:
The French Turbo Cup Cars provided a power output of an official
290bhp, effectively the cars put down 300-305bhp. This improvement was
achieved by using a remapped Bosch Motronic, 3bar fuel pressure
regulator, a modified wastegate and “colder” spark plugs.
Besides
that, the Cup Cars were prepared as follows:
The engine was fitted an oil pan featuring increased capacity and an
intake manifold both made from light weight Magnesia. In the engine
bay, a strut brace was fitted and all unnecessary equipment (e.g engine
bay lighting) removed.
The engine was
able to breathe freely thanks to an open, de-catted “cup exhaust” which
lead to better performance and a more spectacular sound compared to the
German cup cars which were equipped with a catalytic converter allowing
Porsche to get some good publicity for carrying out an ecologic race
series and testing the newly developed technology under heavy duty
conditions.
The interior was
stripped out including the deletion of the rear seats, a “Matter” roll
cage and Recaro seats including 5 point harnesses on the driver side
were installed.
All comfort
equipment such as AC, radio, stereo, central locking, electric windows
and power-assisted steering was removed allowing the car to loose
weight considerably.
The exterior was
changed only slightly by fitting lighter cup mirrors, replacing the
fog-lights by air intakes for cooling the brakes which were borrowed
from the 928 S4 that used larger, drilled discs and race pads.
On dry tracks,
the Cup cars were run on Magnesia alloys (8/9 X 16”) equipped with
Slicks (245/255 ZR 16). The cars weighed in at 1160kg’s and put down
305bhp @ 5900rpm and 420Nm @ 3800rpm resulting in serious performance
figures: The sprint from a standstill to 100 km/h (60mph) was done in
only 4.4 s, a kilometer from standstill took 22.8s and top speed was
300+ km/h (The cars were clocked at 305km/h on the famous
Hunaudières in Le Mans).
The history of
the Turbo Cup Cars is unknown to many Porsche enthusiasts although the
Turbo Cup was the first of the nowadays very popular one make race
series that Porsche carried out and although the French Cup cars
outperformed the 964 Carrera Cup cars which are extremely popular and
getting more and more expensive nowadays.
(Below) 944 Turbo Coupé Artist´s Impression Engine: in
line four-cylinder engine with Turbocharging,water-cooled Displacement:
2479 cm³ Output: 162 kW (220 HP) at 5800 rpm (model year 1985 -
1988), 184 kW (250 HP) at 6000 rpm (model year 1989 - 1991) Top Speed:
245 km/h (model year 1985 - 1988), 260 km/h (model year 1989 - 1991)
|
Large-displacement four cylinder with
running smoothness of a six cylinder The 2.5 litre four cylinder
in-line engine is based on the V8-engine of the Porsche 928. Thus
roughly 50 identical components could be used. The cylinder-head design
and the valve timing inclusive of the hydraulic valve-clearance
compensating elements were adopted from the 928 model, so that the
parallel valve arrangement and the cross-flow principle were defined.
The so-called "open-deck" design, in which the cylinders are exposed
without any additional ribbing, in order not to impede the flow of
coolant, was also adopted. Because of the relatively large cylinder
diameter (100 mm) and due to the influence exerted by the weight of the
pistons on the balancer-shaft imbalance, lightweight pistons were used,
in which the piston-pin support was released from the piston skirt and
set inwards.
To compensate for the forces of inertia and second-order moments
balancer shafts were used, which were based on a principle developed by
Frederick Lancaster in 1903. To mount these shafts Mitsubishi patent
rights had to be used for which a licence fee had to be paid. A
double-side toothed belt with special tooth shape drove the two
specially balanced, cast balancer shafts at double speed,
contra-rotating to the crankshaft. The total weight of the balancing
equipment was 8.1 kg and it required a maximum power consumption of 3
kW.
An oil-water heat exchanger integrated into the engine served to
provide fast oil heating after starting up and thus for lower wear and
a reduction in frictional power, as well as a reduction in speed
dependence of the oil temperature. Digital engine electronics (DME),
i.e. an L-Jetronic from Bosch in combination with a digital technology
electronic ignition-timing advance provided the mixture formation and
ignition for the unit developing 163 hp/ 120 kW at 5800 rpm. Built:
1981 to 1991
|
