But it was Henry Segrave in the Sunbeam who narrowly won from Meo Costantini's Bugatti and André Morel in a Delage. The dominance of Alfa Romeo dissuaded Bugatti and Delage from the Italian Grand Prix. Injuries to their drivers then caused Fiat to pull out and Mercedes were not ready yet so the organisers postponed the race for six weeks. Only four teams arrived for the race in October which would be a contest between Alfa Romeo and the new Mercedes. But when Louis Zborowski crashed his Mercedes and was killed, the rest of the team was withdrawn. Ascari won, leading a 1-2-3-4 result for Alfa Romeo. With the increased Interest in the 2-litre formula, voiturette racing fell back into the background predominantly for local and lead-in races. This year the results were shared between the Talbot 70, the Salmson VAL and new arrival Amilcar. Sources:  Note *: Race reduced from 12 to 10 laps (375km) because of bad weather. Note **: Race had been postponed from 7th September. The third year of the AIACR (forerunner of the FIA) 2-litre regulations for Grand Prix races remained unchanged. In the United States, the American Automobile Association (AAA) stayed with the same regulations as well – the only difference being that the AAA no longer required a mandatory mechanic on-board so single-seater cars became popular. The Targa Florio regulations remained open to any sized cars. The only change was that the smallest engine class (up to 1.1-litres) was further split to create an even smaller class up to 750cc. Unsurprisingly, after the dominance of the supercharged Fiat 805 the previous year, many companies looked at creating their own supercharged model. Fiat continued to develop their successful supercharged 805 model, improving its power output from 130 to 145 bhp. Sunbeam installed a Roots supercharger to their Grand Prix engine, lifting its power output from 105 to 138 bhp. Instead of forcing air into the carburettor, this new supercharger forced a fuel-air mixture direct into the engine. Sunbeam were the first team to use this version of supercharging. The improved engine was placed into a new, lower chassis. At Alfa Romeo, Vittorio Jano developed upon the ill-fated P1 model with the new P2. He designed a new twin-cam 2-litre straight-8 engine, with a Roots-type supercharger attached.