MANAMA, April 4, 2008 (AFP) - Double world champion Spaniard Fernando Alonso said Friday he faces a difficult weekend ahead of him in the Bahrain Grand Prix.

He said his Renault car does not suit the Sakhir circuit following Friday´s free practice for the Bahrain Grand Prix.

He said he hoped overnight changes would improve his form on Sunday, after ending the second free practice session down in 12th position, two places and half a second back from his team-mate Brazilian Nelson Piquet.

Alonso said: "Obviously we are not very competitive and we need to work overnight to change everything, because we are not very happy today.

"We are obviously too slow so it is not easy to know where we are losing all the time. We believe braking stability has been quite bad all day, and traction has been probably our biggest problem today as well.

"So here in Bahrain, to have poor braking stability and poor traction is killing your lap time."

Alonso warned that his R28 car´s problems in Bahrain could be inherent to the chassis after trying different set-ups.

"We tried a couple of different things to sort it out in terms of setup, but the car seems not really to change much with the changes so I am afraid it is just the car not suiting this track," he said.

His problems were made worse by a late collision with Force India´s German Adrian Sutil.

Alonso said it was his fault. He said he locked up and clattered into the German at Turn One, late in the second session.

"I braked too close to him, I lost the down-force and locked the rear tyres," he explained. "I felt I was having a spin in braking, then I controlled the car and it was too late. I was into the corner with too much speed."