at SilverstonePhil Quaife stormed to a double pole position in qualifying at Silverstone  ahead of rounds 17 and 18 of the Porsche Carrera Cup GB. The Jota Sport driver bagged his first ever Carrera Cup pole for round 17 and then made it a perfect session by posting a second best time that was good enough to take pole for round 18 as well.In a dramatic qualifying session, Quaife a mighty pace with a late run to knock PCGB VIP racer Nick Tandy off the top of the times, as championship leader Michael Caine (Team Parker Racing) took fourth and second slots on the respective grids. However, things were very different for his major title rival Tim Harvey (Red Line Racing), who will start from sixth and fifteenth places after spinning into the gravel on only his third lap of qualifying.The battle for the pro-am1 continues to be very hard fought as Nigel Rice (Red Line Racing) headed points' leader Tony Gilham (ReDesign Racing) by less than a fifth of a second and Steve Rance (Parr Motorsport) just set the pace from Glynn Geddie (Parr Motorsport/Apex) to be top of the pro-am2 category. "I'm really happy," said Quaife. "It was all down to the second run and we've taken another big step forward this weekend. I'm just pleased for the team, because everyone has worked so hard this year." Tandy, meanwhile, made an impressive debut and was only toppled from pole by three-hundredths of a second. "That's not too bad really; I got caught out by yellow flags on my second run," he said after taking fourth on the grid for round 18.Tim Bridgman will start third on the grid for both races and knows that he still has a shot at the championship, despite trailing Harvey by 18 points and Caine by 23 points. "The team has done a great job, but the car needs some more front end grip," he said.Caine will start from fourth and then third on the two grids, with Sam Hancock (Jota Sport) and Harvey next up for round 17. For Harvey, it all went wrong very early in qualifying. "I missed the brake pedal initially, and I was 50 yards past my braking point when I got back on the brakes," he explained. At the time, he was on what looked like being a pole lap, but his session was over and the title contender will start way down the field for round 18. However, Harvey was philosophical about the situation. "I've got some racing to do. But we know we've got a good car," he said, looking ahead to a pair of races that are now likely to be crucial to the outcome of the championship.Rice headed the pro-am1 times for both races with another fine performance and will start sixth overall for round 18. However, Gilham is chasing hard and retains the points' advantage in the pro-am1 category. "I struggled to find a clear lap," said Gilham, who is split from Rice on both grids by pro racer Charles Bateman (Team Parker Racing).The stage is also set for some great battling in pro-am2 as Rance just headed team mate Geddie in both grids. "It's a reasonably good time, but I'm still learning," said Rance. Close behind Rance and Geddie in the very competitive category were Alasdair McCaig (Apex Tubulars/Qserv), Graeme Mundy (RSS Performance) and Paul Hogarth (IN2RACING).