Shanghai pit entry altered after crash

Engel hit the beginning of the pitwall head on after he clipped the inside wall at the previous corner. The pitwall was protected by several tyres, but the impact was still a big one.

Drivers had raised concerns over the pit entry before Friday's running commenced, as the pitwall began on the exit of a kink, on a narrow part of track.

Officials promised to review the pit entry immediately after Engel's crash, and the wall was moved overnight. The pit entry now starts sooner and is narrower, which in turn has made the circuit wider.

"This was the kind of crash we were all worried about before the session," said Engel. "If it didn't happen in practice it would have probably happened later in the weekend.

"I just clipped the opposite wall - it was a glancing blow but there was no margin for error there. The gap between the walls was so narrow that as soon as you got it slightly wrong there was nowhere to go."

Engel's Mucke Motorsport team worked through the night to fix his destroyed car. The team was still working on the car when Saturday morning's free practice session began, but Engel was hopeful that he would get back out on track.

"Considering what the car looked like last night, the guys have already done an amazing job to get it to the stage it is now," he said.

"I can't thank them enough for the work they've put in. With us being on the other side of the world they've had to improvise quite a bit.

"We'll hopefully get out on track at some point. And to be honest, even if it turns out the car is not right when we try it, to even get it back on track at all will be a real achievement."

Other minor changes were made to the track overnight at the request of the drivers. More tyre walls have been added at certain corners, and the escape road at Turn 5 has been expanded. The pedestrian crossings at the long final corner have also been ground down after several drivers had near misses in the fast right-hander on Friday due to the bumps.