- John Oreovicz, Autos, Open-Wheel
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With Florida hoping that Ivan was the third and final strike of the hurricane season, the Indy Racing League arrives at Homestead-Miami Speedway this week for the first test of the IndyCar Series' road racing package.
The testing Wednesday and Thursday will be closed to the public and media.
As such, don't expect to hear anything but positive emanations coming out of Homestead. But the truth is that the IndyCars will require a considerable amount of work to be road course ready.
"We're not going down there to set any track records," said Phil Casey, IRL's senior technical director. "We're just going down there to make sure everything works properly on a road course. All the parts are built. We want to have good transmissions and brakes and don't want to have any unforeseen problems come up. We just have to see it work on the track like we think it will."
Some insiders believe it will cost upwards of $150,000 per car to make the necessary changes for road and street course racing. The IRL has raced exclusively on ovals since the series inception in 1996, though basic provisions for road racing were engineered into the current generation of cars that debuted in 2003.
"We did about two-thirds to three-quarters of the changes during our update kit from the end of the 20003 season into 2004 by changing the radiators and the sidepods to enable for better cooling to go road racing," said Brian Barnhart, the league's senior vice president of racing operations.
The bulbous sidepods introduced in 2004 were also intended to keep cars from interlocking wheels. But they may need modification for road racing, along with the snug-fitting energy absorbing collar that surrounds the cockpit opening, in an effort to increase driver visibility.
While changes to the tub itself are minimal, chassis manufacturers Dallara and Panoz G-Force didn't get away scot-free. Their update kits include all parts needed to modify everything on the car except the gearbox and engine for road racing. The Panoz G-Force kit contains 335 individual pieces, right down to the nuts and bolts necessary to put it all together.
"I'm sure after the Homestead test we'll have a job list as long as my arm," laughs Simon Marshall, Panoz G-Force chief designer. "We're probably underestimating the amount of time and work it's going to take once they have run."
The most visible changes in the chassis kit include strengthened suspension arms with geometry modified to allow the car to take on both right- and left-hand turns. But Marshall says the biggest difference is in the brakes.
"The brakes will be a hell of a lot better and therefore we need to cool them," he said. "But we'll use standard hubs -- I think high-speed ovals have shown the bearings are fairly bulletproof."
The IRL will work with the five teams elected to do the initial testing to determine a basic brake specification. Still in question is whether the league will mandate carbon or cast-iron rotors.
"We're trying several different combinations, using everything from steel rotors to carbon rotors and three different brake calipers," Casey remarked. "We just want to see how the cars perform on a road course and see if there is enough cooling because there is much slow running on a road course."
The drivetrain will also require changes and many of the drivers have questioned whether the spec X-Trac gearbox can withstand the forces of road racing. A gearbox problem knocked Dario Franchitti out of the IRL's most recent event at Chicagoland Speedway, and the Scotsman must have lost his speaking points when he addressed the issue afterwards.
"We lost a gearbox under the yellow, if you can believe that," Franchitti said. "I don't know how this gearbox is going to survive a road course. It's not the strongest part of the car, put it that way."
Many of the components in X-Trac's IRL gearbox have been used for years in endurance racing. With the peaky powerband of the 3.0-liter engines instituted in the IndyCar Series this year, drivers are shifting a lot more, and teams have learned how to build a more reliable gearbox within IRL rules. Beefed-up halfshafts will be included as part of the Dallara and Panoz G-Force road racing update kits.
"It will not be a new gearbox," confirmed Andrew Heard, X-Trac's Manager of U.S. engineering and track support. "The only change will be removing the spool and putting in the differential housing.
"If the first test at Homestead goes fine, then I'll be pretty happy at that point. If we find we have an oiling issue at the test, we're confident we already have a fix for it; it's just a case of manufacturing the parts, which can be done in a matter of weeks. And I wouldn't feel we need a huge amount of testing on that either."
Engine manufacturers Honda, Toyota and Chevrolet have also been working hard on a road racing version of their 3.0-liter engines. Until now, the motors have been tuned for peak power, but the manufacturers have switched their quest to find more torque.
"Because of the IRL rules, there is not a lot we can do because the engine fundamentals are fixed," remarked Robert Clarke, general manager of Honda Performance Development. "We'll be focusing on driveability, which is where we excelled with our CART program. We lost a lot of torque in changing from the 3.5-liter to the 3-liter program. It's not a very responsive engine to begin with and it's a very heavy car, so I'm sure that's a concern of the IRL."
Clarke said that raising the rev limit sounds like a simple solution to the problem, but it isn't.
"It sounds easy but there is a knock-off effect on all the moving engine components," he said. "When everything is re-designed for 2007, the engine needs to be properly sized because it's way too large for what it is. We designed the parts heavy just to make the minimum weight."
The IndyCars are likely to be seven to 10 seconds a lap slower than Champ Cars, a disparity that fans of the latter series are likely to highlight.
"The only concern is when you start comparing them to some other series," Clarke said. "But I think the cars will be fine and they'll put on a good show. That's what counts."
The drivers and teams participating in the test are Franchitti of Andretti Green Racing, Alex Barron and Ed Carpenter of Red Bull Cheever Racing, Sam Hornish Jr. and Helio Castroneves of Marlboro Team Penske, Scott Dixon and Darren Manning of Target Chip Ganassi Racing, and Buddy Rice of Rahal Letterman Racing. Each team will run one car.
John Oreovicz covers open-wheel racing for National Speed Sport News and ESPN.com.