When Fiat absorbed Abarth in the Summer of 1971, the small manufacturer effectively became Fiat's competition department. Running the successful but expensive prototype racing program was entrusted to Enzo Osella. His small company had previously already been responsible for offering customer support to privateers campaigning Abarths.
Despite the organisational changes, Osella-tweaked Abarths took five out of ten wins in the 1972 running of the highly competitive European 2-Litre Sports Car Championship. With the other manufacturers like Chevron and Lola continuously developing their cars, Osella could however not rely on the ageing Abarths for another season. Instead, he expanded his business and turned out 'his' first sports prototype ahead of the 1973 season.
In many ways still a development of the Abarth SE021, the new 'Abarth-Osella' was dubbed the PA1. This was short for 'Prototipo Alberto' in honour of former Abarth and Osella engineer Alberto Guerrato. He was also a close friend of Enzo Osella, and had just succumbed to an incurable disease. The Abarth name was retained as a reference to the engine used and also provided the customers with a sense of continuity.
The new PA1 was a wholly conventional design, built around a riveted sheet-aluminium monocoque chassis. The double wishbone suspension at the front was bolted directly at the tub. At the rear a tubular subframe was used to take the load of the multi-link suspension. Coil springs over dampers and ventilated discs were used on all four corners, while both the front and rear end featured anti-roll bars.
As mentioned earlier, Enzo Osella still relied on the purpose-built four cylinder Abarth engine. Displacing just under 2-litre, the thoroughly modern unit boasted two overhead camshafts, four valves per cylinder and Lucas fuel injection. In its latest specification, the Abarth engine produced around 270 bhp at 8,700 rpm. It was initially mated to a Hewland FT 200 gearbox but this proved not reliable enough so the sturdier FG 400 was used instead.
The body used on the PA1 was a subtle evolution of the design used so successfully the previous season. The main change was at the tail, which in 1972 still used a separate rear wing. In its original guise, the smooth design sported two small spoilers integrated in the left and right corners of the tail. The final version, however, featured a full-length aerofoil that was mounted as an integrated part of the bodywork.
Building on the success of the previous season, Enzo Osella managed to build and sell or race ten PA1s. The season did not get off to the best of starts but eventually Vittorio Brambilla and Arturo Merzario managed to score a win each in the eight-round European Championship. In the manufacturers' standings Abarth-Osella had to settle for third behind Lola (five wins) and Chevron (a single victory).
Ahead of the 1974 season, Osella developed the Abarth-Osella PA2, which sported an even smoother body. It would be the last sports prototype to bear the Abarth name but it faced even stronger opposition. On his own, Osella would continue to produce sports racers and single seaters using a wide variety of engines. The PA1 remains as the final 'Scorpion-badged' sports racer to win a round of the European Championship.
Article by Wouter Melissen, last updated on January 21, 2013
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