The toughest stretch of the Indy Racing League schedule wraps up Sunday with the Firestone Indy 400 at Michigan International Speedway (ABC, 3:30 p.m. ET), the second-longest race of the IndyCar season.
The IRL has only been running at Michigan since 2002, but those four races only continued the fast, wacky and unpredictable tradition of USAC- and CART-sanctioned open-wheel races at MIS.
Thankfully, the IRL didn't replicate the abysmal mechanical reliability that marred the USAC era or the massive crashes that marked the CART races of the early '80s. But for one reason or another, during the IRL's stewardship of the MIS open-wheel date, the winner of the Michigan race generally has been an outsider to the overall season storyline or championship battle. Whether it was Tomas Scheckter dominating in 2002, Alex Barron doing a spin-to-win in 2003, or Bryan Herta having his best race of the season to grab the trophy in 2005, the Michigan race has seemed to produce a surprise ending.
Only Buddy Rice's 2004 victory fit the form chart.
So if any track is likely to shake up the established order in the IndyCar Series, it's Michigan, which has taken over from California Speedway as the IRL's fastest track not called Indianapolis. The pole speed, depending on the wing package mandated, has ranged between 216 and 222 mph and the race pace is often blistering. The '03 Michigan race, when Barron held off a charging Sam Hornish Jr., was one of the fastest and closest races in IRL history.
Unfortunately, because Michigan is such a fast track, the advantage that Penske Racing and Ganassi Racing have enjoyed so far in 2006 should be magnified. Saddled with uncompetitive Toyota engines for the last few years, those teams honed their superspeedway aero package. Now that they have the same Honda horsepower as everybody else, Penske and Ganassi have pulled clear of the rest of the field, including Andretti Green Racing.
Honda Performance Development President Robert Clarke is not surprised at how the 2006 season has played out, with Penske and Ganassi winning every race until AGR's Tony Kanaan finally broke the streak last weekend at the Milwaukee Mile, the IRL's most handling-critical oval.
"Our top teams were enjoying an advantage with our engine and frankly, I think were lazy in that they did not address areas of the car in their own program," Clarke remarked. "That's why they are suffering."
Indeed, it's on "horsepower" tracks like Motegi, Texas and Kansas where the former Honda house teams like AGR and Rahal Letterman Racing have struggled for speed. And Michigan definitely qualifies as a horsepower track.
The disparity between teams is more obvious in qualifying, and AGR's Kanaan occasionally has been able to stay with the Penske and Ganassi cars on the big tracks. But it's harder to pass on race day when everyone has the same engine, which has made qualifying up front more important than it used to be.
Ray Leto, who engineers Danica Patrick's entry for the Rahal Letterman team, said he believes that the IRL's adoption of a Honda spec engine package has altered radically the way IndyCar teams and drivers must approach qualifying.
"Given extra horsepower, you have a pretty good advantage almost everywhere, but mostly on the fast tracks," Leto said. "This year it's the same horsepower for everybody so qualifying comes down to being able to get the car really hung out but tracking along the bottom of the race track for one lap. That comes from getting the setup right with the right aerodynamics on the car and the driver really hanging the thing out. It's actually a different discipline or exercise this year."
Rahal Letterman has started to get the handle on the Dallara chassis after its midseason switch from Panoz, as evidenced by Patrick's consecutive fourth place finishes at Nashville and Milwaukee. But the most likely challenge to Penske and Ganassi will come from AGR, which should benefit from a test day Kanaan ran at Michigan last week.
Still, they'll all again be chasing the IRL's two superteams and their four drivers, who are all within 32 points of series leader Hornish. But even in a four-man championship, there are some intriguing storylines.
Hornish needs to pad his lead on the Michigan and Kentucky Speedway ovals in case he has a poor result in the championship's penultimate round on the Infineon Raceway road course in late August.
Dan Wheldon (Ganassi) and Helio Castroneves (Penske) need to stay within striking distance of the series lead, if anything so that they are not asked to assume a number two role to help their teammates' championship chances.
Meanwhile all Ganassi's Scott Dixon, the 2003 series champion, has to do is to keep quietly racking up the points.
Other than the noise produced by the raucous Honda engines, it's likely to be a quiet two-day race weekend at MIS. The IndyCar race is the only event on the docket, so there will be plenty of down time.
While the Michigan NASCAR races produce overflow crowds and nightmarish traffic, open-wheel attendance at MIS has dropped steadily since the open-wheel split of 1996. Track officials are expecting a crown of around 30,000 on Sunday amid reports that the IRL is negotiating to bring back the Belle Isle street course last used by CART in 2001.
John Oreovicz covers open-wheel racing for National Speed Sport News and ESPN.com.