Škoda 739 : aerodynamics gone by the wayside

At AZNP, it was confidentially called the Green Jumper because of the “expression” of the arc and the paint shade inspired by Bertone's concepts. The specially designed coupe was to replace the beautiful 130 RS, but it never received a brutal deployment.


At the turn of the 70s and 80s, the Skoda 130 RS with its rear engine enabled Mlada Boleslav's brand to reap laurels in world rallies and on European 1300 class circuits. However, in 1977 plans to modernize it have been drawn up. The UVMV Research and Development Center, located in Prague, was responsible for the work. This is where we began the study of a replacement with an aerodynamic body of the Skoda 735, the code name which internally designated the Skoda 130. It was not strictly speaking a car. racing but a real rolling laboratory.


The Škoda 739 had improved aerodynamics


The new Škoda 739 was to be the result of the latest technology and knowledge in the world of motorsport. It had to learn from the faults of the original Škoda 130 and become a great racing car, a new icon. The main task was to work on the aerodynamic properties and improve them. First, a 1: 5 scale model was built which was then tested at the Aeronautical Research and Test Institute (VZLU). There was no other option at the time as it was the only place where there was a wind tunnel. The results, of course, after a few tweaks, turned out to be more than encouraging and that is why a running prototype then followed. The latter was manufactured by Mlada Boleslav's prototyping workshop, which had received all the necessary technical documentation. AZNP (the official name of Skoda during this period) was therefore also actively involved in this project.

The aerodynamic changes had a positive effect on fuel consumption at high speeds. This detail was important on a racing car because it should not be forgotten that this model was intended to be entered in endurance events of 500 km or 3.5 to 4 hours with a change of driver. This lower consumption meant fewer pit stops ... So compared to the Skoda 130 RS and 150 km / h, consumption was reduced by 5 liters per 100 km! And for a racing car, 10 liters per 100 km was really little.


The Skoda 739 was based on its predecessor but only resumed its middle part as you can clearly see at first glance. The rest of the body was completely redesigned. This beautiful car was distinguished by its long sloping front hood and prominent headlights. They were only covered with plexiglass bubbles afterwards. There was also a large spoiler with huge long-range headlights.


Mechanically, the Skoda 739 differed from the 130 RS only in a few details. The engine was still a naturally aspirated, water-cooled 1.289 cc (75.5 x 72 mm) 4-cylinder mated to a four-speed gearbox. It was also an old racing car that had given its exhaust, including the silencer that was hidden behind the wraparound rear bumper. The OHV overhead valve timing was already seen as a weakness although this type of engine was still in use for a few years. The two valves per cylinder were not yet. Fuel was supplied through a pair of Weber carburettors. The crankshaft had three bearings, the cylinder head with rectangular intake and exhaust ducts was replaced by a new cylinder head with circular ducts. Engineers from UVMV and CVUT had worked together to modify the engine and even used computers. This allowed them to pull 100 horsepower at 6,500 rpm.

The chassis with a wheelbase of 2.4 meters had a triangulated rear suspension and work had also been done on improving the braking system with ventilated front discs. The four-piston calipers were chosen during testing of discs of different diameters on the Jablonec circuit. The widening of the front fenders made it possible to install air vents just in front of the doors.



Progressive springs were also new. The fuel tank was installed just behind the front axle, allowing an almost upright space in front of it for the spare tire. While the priority was to increase safety, this also made it possible, during the race, to not modify the weight distribution as the tank emptied. The filling was done on the right side at the foot of the windshield.

The tracks were 1420 and 1370 mm respectively. Depending on the gear ratios chosen, this car, which weighed just 827.5 kg, could go from 0 to 100 km / h in 9.25 seconds, cover the kilometer from a standing start in 30.7 seconds and reach 191 km / h.


The end,

Initially the prototype was covered in a beautiful green color but eventually it was repainted in the race colors: white with blue and red stripes and an all-blue hood. It was in this form that he made an appearance in 1981 in the paddock of the Brno Grand Prix as part of the European Circuit Racing Championship. But since the FIA ​​had just introduced Groups A and B, development of the Skoda 739 was halted. The hope of seeing her in a race had faded. Mass production was however envisaged and the cars should have received retractable headlights because the headlamps were reflected in the plexiglass bubble and they were very difficult to adjust.

The only copy ever built is kept at the Skoda Muzeum of Mlada Boleslav in its racing livery with the number 6. The international homologation of the Skoda 130 RS which was to expire at the end of the 1981 season was extended for two years and in the 80s, this model continued to be engaged in local races. In the mid-1980s Skoda entered Group B with the 130 LR sedan, but that's another story.



Published technical parameters:

Wheelbase 2400 mm, front / rear track 1420/1370 mm, dimensions 4100 x 1620 x 1230 mm, empty weight 827.5 kg. Top speed 191 km / h, acceleration 0-100 km / h in 9.3 s. At 150 km / h the car sprayed 10 l / 100 km.






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