Briscoe leads Castroneves at Sebring

With the 1.7-mile short circuit's grip increasing day-by-day, Briscoe's 52.758 laptime was predictably quicker than Group 1 pace-setter Tony Kanaan had managed on Wednesday for Team Andretti Green.

But the Australian, who signed to replace Sam Hornish Jr in the IRL squad last winter after two years in the Penske organisation's ALMS Porsche LMP2 programme, was happy with his pace as he continued to re-acclimatise to life in IndyCars.

"The track seemed to clean up really quickly during the afternoon and the rubber that the guys laid down over the last couple of days is still there," said the former Ganassi IRL driver.

"It's just a bit tough here sometimes, because you are chasing the track conditions.

"Overall, we're really happy with the work we got done today on the car. We did a lot of set-up work, just trying to build a database of tools we can work with when we go to St. Petersburg."

St. Petersburg resident Dan Wheldon was third quickest for Ganassi ahead of his teammate Scott Dixon, although the two former IRL champions were both more than 0.5 seconds off the pace set by Briscoe.

2004 Indy 500 winner Buddy Rice was fifth fastest for Dreyer & Reinbold Racing.

"For us to be on the pace with two of the big three teams is quite good," he said.

"We've had all winter to sit and think about what we need to do. We haven't done a road course since Detroit (in September) so I think we have a lot more things to go through and a lot more to evaluate, but I think we're in good shape."

AJ Foyt Racing's Darren Manning, Panther's Vitor Meira and Milka Duno, also driving for D&R, completed the order.

Wednesday's times:

Pos  Driver                    Time       Speed     Laps
 1.  Briscoe                   52.7757    113.916    64
 2.  Castroneves               52.9853    113.465    57
 3.  Wheldon                   53.4806    112.415    69
 4.  Dixon                     53.4959    112.382    47
 5.  Rice                      53.7294    111.894    65
 6.  Manning                   54.3847    110.546    25
 7.  Meira                     54.4123    110.490    79
 8.  Duno                      56.4081    106.580    50