Detroit: Franchitti and Dyson out front early

Dyson Racing’s Marino Franchitti made a late jump to the top of the timing chart Friday morning in the first practice for the Detroit Sports Car Challenge by Bosch. Franchitti put the Porsche RS Spyder that he will drive with Butch Leitzinger in front with a lap of 1:23.240 (89.524 mph) on damp but drying circuit in Belle Isle.

LMP2 entries from the American Le Mans Series held the top four positions from the 90-minute session. Acura entries were second, third and fourth with Andretti Green Racing’s Franck Montagny and James Rossiter 2.551 seconds behind Franchitti in their Acura ARX-01b. Lowe’s Fernandez Racing’s Adrian Fernandez and Luis Diaz were third at 1:26.221 (86.429 mph) with the Patr¢n Highcroft Racing Acura of Scott Sharp and David Brabham third in P2 at 1:26.951 (85.703 mph).

Audi Sport North America’s Marcel Fässler was the fastest driver in LMP1. The Swiss driver got his first taste of racing at Detroit with a time of 1:27.694 (84.977 mph) in the Audi R10 TDI that he will drive with Emanuele Pirro.

His time was good enough for fifth overall and was more than a second ahead of the sister car of class championship leaders Lucas Luhr and Marco Werner. The pairing has won seven straight P1 rounds and captured the last three overall Series victories.

Corvette Racing’s Oliver Gavin set the fastest time in GT1 at 1:36.355 (77.339 mph). Gavin was about a half second quicker than Bell Motosports’ Aston Martin DBR9 of Terry Borcheller and Chapman Ducote.

In GT2, Dominik Farnbacher clocked the fastest time in Tafel Racing’s Ferrari F430 GT. Farnbacher, who will team with Dirk Mueller, posted a lap of 1:36.566 (77.170 mph). He was more than a second quicker than the Flying Lizard Motorsports Porsche 911 GT3 RSR of Wolf Henzler and Jörg Bergmeister. A second Flying Lizard Porsche of Martin Ragginger and Lonnie Pechnik sat third at 1:38.320 (75.793 mph).

A reminder that today’s qualifying session will be streamed live online on SPEEDtv.com beginning at 4:30 p.m.