The famous Zandvoort circuit in the Netherlands will provide a new challenge for the Oman Air Motorbase team during rounds eight and nine of the Avon Tyres British GT Championship this coming weekend (7/8 September).With neither Ahmad Al Harthy nor Michael Caine having ever raced at the Dutch track before; the Oman Air Motorbase duo face a big challenge in their bid for championship success in the Motorbase-run Porsche 911 GT3R.The pair of hour-long races on the former Dutch Grand Prix circuit is another of the highlights of the 2013 British GT season; but the Motorbase team will once more be handicapped by a major weight penalty. All season the Oman Air Motorbase car has been carrying a 75kg weight penalty due to the championship organisers grading of the two drivers. However, the speed of the Porsches has attracted further penalty as the season has developed and the Motorbase car will go to Zandvoort with a massive 130kg of ballast on board: 75kg more than the championship leading Trackspeed cars.Ahmad and Michael have never been to Zandvoort before, so we are heading there blind, said team boss David Bartrum. We are going there very disadvantaged as we are carrying the weight penalty. If we are going to consolidate our championship position or go even better; then we need to make the most of these two races and score good points in both. We've got two good drivers who work very well together and we've got a very well drilled team.I've only been to Zandvoort once and that was in 2005, recalled Bartrum. We went to help run a couple of Porsches we had sold. It was early in the season and we came off the boat and it started to snow. We got to the circuit and the snow was about a foot deep. We thought wed be going home, but they got the snow ploughs out and we went racing.Following free practice sessions on Friday 6 September, qualifying and round eight of the Avon Tyres British GT Championship will be on Saturday 7 September.  On Sunday, there will be an un-timed warm-up session followed by round nine of the championship.