McNish on overnight pole

The 30-year-old Scot outpaced Audi team mate Emanuele Pirro by two tenths of a second to stake his claim for a third pole of the season in temperatures in excess of 40 degrees centigrade.

McNish said: "I went out right at the start because I was worried about gravel being sucked up onto the circuit but, in fact, the track got quicker and quicker as the session went on."

The former Le Mans 24 Hours winner expects that he will have to improve on his time about his Audi R8 prototype in Saturday's 20-minute qualifying session if he is to maintain his position at the top of the timesheets. "This is a new track, so the grip level is going up all the time. I think tomorrow will be quicker."

Third fastest, a full half second behind Pirro, was Jan Magnussen in the first of the two Panoz LMP Roadsters. In turn, the Dane was a further six tenths clear of JJ Lehto in the number one BMW V12 LMR he shares with championship leader Jorg Muller.

The lone factory Chevrolet Corvette qualified on provisional pole in the GTS class in the hands of Ron Fellows. The Canadian was nearly a whole second ahead of the ORECA Dodge Vipers, which are unbeaten since joining the ALMS more than one year ago.

"It was an ugly lap. I was a second and a half slower than we ran this morning because of the higher track temperatures," he said.

The Dick Barbour Porsche team reasserted its dominance in the GT class after relinquishing its stranglehold on the "baby" class of the ALMS last time out at Mosport.

Dirk Muller outpaced team mate Sascha Maassen by three tenths of a second, while Mosport winner Randy Pobst was a similar distance behind in third aboard his Alex Job Racing Porsche.

Muller said: "My car seemed to be sliding around a lot, but it must have been sliding about less than everyone else."

Second qualifying takes place on Saturday afternoon little more than four hours before the race begins at 7.00pm in the evening.

American Le Mans Series, First Qualifying, September 1

1 Allan McNish (Audi R8) 1m13.242s
2 Emanuele Pirro (Audi R8) 1m13.481s
3 Jan Magnussen (Panoz LMP Roadster) 1m13.923s
4 JJ Lehto (BMW V12 LMR) 1m14.586s
5 Hiroki Katoh (Panoz LMP Roadster S) 1m14.590s
6 Jean-Marc Gounon (BMW V12 LMR) 1m15.741s
GTS Ron Fellows (Chevrolet Corvette C5-R) 1m20.614s
GT Dirk Muller (Porsche 911 GT3-R) 1m24.872s