The first two-hour race of the Avon Tyres British GT Championship is the next challenge for the Oman Air Motorbase team this weekend (5/6 May) at the spectacular Rockingham circuit in Northamptonshire.Mondays two-hour race has drawn a stunning entry as some of the top GT teams in Europe take on the British pack and more than 30 cars are due to line up for Mondays race. Among them will be Ahmad Al Harthy and Michael Caine in the Porsche 911 GT3R entered by Motorbase Performance.Team boss David Bartrum says the team will be working hard to score a podium finish, but says that carrying 75kg of ballast due to the strength of the driver pairing is a big issue.Ahmad has learnt a bit more about the car and Michael is looking forward to getting back in the car, said Bartrum. We can hopefully build on what we learnt at Oulton Park but weve still got this 75kg penalty and we are struggling with it.Im really looking forward to being back in the car and back with the guys at Oman Air Motorbase, weve got high hopes for Rockingham, said Al Harthy. The two races at Oulton Park went very well for us, scoring points in both was a fantastic start to my GT career and the team did a great job with our race set-up. Were feeling quite confident going into the first two-hour race of the British GT season: we had a positive test at Rockingham so the aim is to fight for our first podium of 2013.Following a pair of one-hour free practice sessions on Sunday 5th May, qualifying for the second round of the Avon Tyres British GT Championship will take place at 16.20. The two-hour race starts at 13.05 on Monday 6 May.