The Thruxton circuit in Hampshire, the fastest on the calendar, is the venue for rounds five and six of the Porsche Carrera Cup GB over the weekend of 5/6 May. With three winners from four races and at least three more potential winners on the grid, the Carrera Cup GB is wide open right now.It all started perfectly for Tim Harvey (Red Line Racing), with two wins at Brands Hatch. By his own high standards, Tim didn’t have such a good weekend at Rockingham but still heads the table by seven points heading to Thruxton. Importantly, he set a searing pace when the cars tested there last month and he is likely to be the benchmark for the weekend.However, Harvey knows that the opposition is tough and two young former single-seater racers are standing out as major rivals as they learn about Porsche racing. Former F3 racer Steve Kane won superbly at Rockingham for Motorbase Performance, while James Sutton – having moved over from Formula Renault – led for many laps at Rockingham for Red Line Racing before hitting a tyre problem.Kane now stands only seven points adrift of Harvey, while Sutton is fast emerging as a bright young talent and both of them will be pushing Harvey very hard on the high-speed sweeps of Thruxton. "Rockingham was just what I needed for the championship," said Kane, who scored maximum points in both races after finishing second in the opening race to guest racer Andrew Kirkaldy.Also challenging Harvey will be Michael Caine (Team Parker Racing), in his second year of Carrera Cup. A first race win in the series cannot be far away for the experienced Newmarket racer. Like Harvey, Caine has the advantage of having raced in the Carrera Cup at Thruxton before and knows how the complexion of a race can change dramatically as tyre wear progresses.For Sam Hancock (Motorbase Performance) and Rob Collard (Team Parker Racing), it has been a case of steady progress rather than outstanding pace to date. Both have the speed and experience to challenge for race wins, but so far they have been picking up places rather than mixing it right at the front. That will surely change soon, and Hancock in particular was impressive at Thruxton during testing.The pro-am category is now in its second season and offers a race within a race as well as a separate podium presentation, points and prize money. Nigel Rice is having a brilliant season for Red Line Racing, with three wins and a second from four races. His big rival is Andy Britnell (Motorbase Performance), while others starting to show in pro-am also include championship newcomer Charles Bateman (Team Parker Racing) and Pete Osborne (Team O). Due to make his 2007 Carrera Cup debut is Maxi Jazz (Red Line Racing), while series newcomer Peter Bamford (Team RPM) will also join the grid.Meanwhile, young single-seater racer Matt Howson will make his Carrera Cup debut in the Porsche Motorsport guest car and he showed during testing that a visit to the podium is within his grasp.