INDIANAPOLIS -- When the rain finally reached the Indianapolis Motor Speedway a little after 3:30 p.m. Wednesday, Sam Hornish Jr. and Penske Racing were back on top of the timing screens. But it wasn't that way throughout most of the second day of practice for the 90th running of the Indianapolis 500.
After Tuesday's dominant 1-2 performance with Hornish and two-time Indianapolis winner Helio Castroneves, Penske Racing looked as though it would be untouchable in this weekend's battle for pole position. That was before Dan Wheldon and Kosuke Matsuura opened Wednesday's practice with sizzling 225-mph laps.
However, Hornish showed that Penske still hasn't played its full hand by moving over 226 mph just before the track closed for the day at 3:55 p.m. The American's 226.056-mph lap was 0.420 mph faster than Wheldon managed in his Target/Ganassi Dallara-Honda.
The apparent ease with which Hornish was able to reel off quick laps must worry his rivals, including Castroneves. The Brazilian, who celebrated his 31st birthday Wednesday, was sixth fastest at 224.258 mph.
"It's a testament to how hard we've worked over the last two years," Hornish said. "It's pretty exciting, but nothing really matters until race day.
"Today, it was nice to run in some overcast conditions, but it's going to take 228-and-a-half or 229 for the pole, probably," he predicted. "It depends on the weather conditions. If we have a nice 70-degree day with no wind, it could be faster than that."
That appears unlikely. The forecast calls for low temperatures and scattered showers all the way through the weekend, raising the possibility that the 11 cars-per-day qualifying format event officials hoped to implement last year will be affected again.
Wheldon and his teammate Scott Dixon ran 3-4 on Tuesday, and defending Indy winner Wheldon looks as if he's ready to vie for the pole Saturday. Dixon was eighth fastest Wednesday at just under 223 mph.
"The team has given me a fantastic car that's really balanced and fast," Wheldon said. "It's going to be a cat-and-mouse game with the weather leading up to qualifying, but given the results today, I definitely feel pretty confident as we prepare for Pole Day and beyond."
Added Dixon: "What the first two days reinforced was that our main competition will once again be the two Penske cars. The tone for the weekend has certainly been set."
All five Andretti Green Racing cars topped 222.5 mph, led by Bryan Herta's 224.292-mph lap. The cat among the pigeons was Matsuura, the 2004 Indianapolis Rookie of the Year who is much more consistent this year now that he is running a Dallara chassis. Matsuura's Fernandez Racing teammate, Scott Sharp, was also quick, running seventh at just under 224 mph.
Not everyone was so happy. Rahal Letterman Racing's Danica Patrick and Buddy Rice ran more laps (66 and 71 respectively) but ended up 12th and 15th fastest. Patrick finally edged over 223 mph in her Panoz-Honda, but teammate Jeff Simmons was parked at 220 and damaged a front wing when he spun five minutes into the day's action.
"It was a little frustrating because right when we wanted to go faster, it rained," Patrick said. "I'm confident we'll go faster each day."
Airton Dare was named Wednesday as the driver of the No. 88 Sam Schmidt Motorsports entry. The Brazilian, a former IRL race winner who recently has raced stock cars in his home country, is the 31st driver nominated to a ride. Roberto Moreno is close to finalizing a deal to run a fourth Vision Racing entry, and an open seat remains at Cheever Racing. The Speedway did a particularly nice job with the program commemorating the 90th running of the Indianapolis 500. The collectible program is available for $10 at Indy500.com.
John Oreovicz covers open-wheel racing for National Speed Sport News and ESPN.com.