The 2005 Michelin Porsche Open Series will conclude at Croft over the weekend of 24/25 September. The 16th and 17th races of a busy schedule will bring the curtain down on another excellent season of racing from the Porsche Club GB.It has been a mixed campaign for the driver who has consistently set the pace in the Porsche Open in recent times. In the 15 races to date, Richard Chamberlain's mighty 935 has consistently been the fastest car, and nine race wins have gone to the Cambridgeshire engineer. But several non-finishes and mechanical dramas have also featured in his year.Now, Chamberlain will head north to Croft, a circuit that he rates among his favourites, determined to make it 11 wins from 17 races. Few would bet against him if the 935 is running well and he dominated the action when the Porsche Open last visited Croft back at the start of the 2004 season.As ever, the biggest rival to Chamberlain is Rupert Lewin in his stunning 996GT2-R, but Lewin has also had a number of technical problems this year. Notably, water system dramas have cost him a couple of race results, but victory over Chamberlain at Rockingham in July will remain a landmark result for Lewin. Other wins at Oulton Park and Donington are also in Lewin's 2005 tally.Joining Chamberlain and Lewin in the top class is Gerry Harrison in his 911GT3RS, potentially a rival for the top two cars at a track where handling can be as important as all-out power.Class two features a legend of north-east motor racing in the form of veteran racer Brian Robinson. With four decades of experience under his belt, Robinson makes a welcome Porsche Open appearance at his home track with his 993RS and could be the man to beat in the division. Simon Mifsud (911GT3 Cup), Paul Hogan (996) and local racer Clive Reay-Young from Harrogate (944 Turbo) are all rivals for Robinson.Class three has three local racers and all of them are in the running for class success. Mike Johnson's very rapid 911SC should set the pace, but fellow York resident Wayne Jackson (944 Turbo) knows Croft well, as does Whitburn's Anthony Oliver (964RS). Relative newcomers Mark Chilton (928GTS) also runs in class three, while class four is contested by the 944s of Simon Ward and Charles Winterhalder.