IRL: About that IRL engine

The 88th Indianapolis 500 Mile Race will be here before we know it - May is just around the corner. To prepare, the Indianapolis Motor Speedway is holding media days, which gives us an opportunity to inform the public of what will be different...

The 88th Indianapolis 500 Mile Race will be here before we know it - May is just around the corner. To prepare, the Indianapolis Motor Speedway is holding media days, which gives us an opportunity to inform the public of what will be different this year.

In a couple of words: a lot. IMS and the Indy Racing League have implemented a number of changes for the competitors to slow down the cars and enhance safety around the 2.5-mile flat oval at 16th and Georgetown Roads in Speedway.

Due, in part to several accidents last year that sent cars airborne, Brian Barnhart, the senior vice president of racing operations and Phil Casey, senior technical director set to work to amend the chassis and engines used by the IRL's IndyCar Series to remedy this problem.

As the Indy cars still have one more race before Indianapolis - at Twin Ring Motegi in Japan - the changes will be implemented publicly when practice begins on May 9th. Prior to that time, the new 3-liter engines built by Honda, Toyota and Chevrolet will run for the first time in a closed test on Saturday, April 3rd.

What Barnhart decreed is a different crank, connecting rods and pistons that will decrease by half a liter, or about the size of a box of cereal. "We're not allowing the engine manufacturers to optimize the engines for a 3-liter," Barnhart noted.

"We're anticipating a reduction in performance of about 90-95 horsepower. We're going to balance that with an aerodynamic package so we maintain proper balance between downforce, drag and engine performance."

Barnhart has stated all along he expects to see speeds drop at the Brickyard by about 10 miles per hour, resulting in qualifying speeds of about 223-224mph, well under Helio Castroneves' 2003 mark of 231.725mph.

When the capacity is reduced, the Indy Racing League will get rid of the 3x12" slot in the air box that reduced airflow to the engine and brought horsepower down by about 20hp. The League has also removed rear tire kickups and the upright blanking plates in an effort to reduce downforce as it brought the slits onboard, but is not saying now whether those items will be permitted with the smaller engines.

Casey agreed that the engine decrease "was the cheapest and most economical way to reduce engine displacement by changing the crankshaft, rods and pistons." That way, he said, engine manufacturers "would have to do a little camshaft work; they wouldn't have to redesign the engine."

By reducing the stroke, or swept volume that goes into the engine, the League hopes to reduce horsepower to a more manageable size. By shortening the amount that the piston moves up and down by about 3/8" the engine loses about half a liter, according to Milt Woods of Speedway Engines.

Casey did note the torque curve might change on the engines, with a bit less torque than before. But then, since the Indy Racing League has had no failures at either of the first two races of the year, Casey has minimal concerns about the changes and their effects on reliability.

Barnhart acknowledged this morning that the accidents of Kenny Brack and the fatal crash here by Tony Renna accelerated the program to reduce engine size by about six months. He had intended to implement these changes for the 2005 racing season, not in May of this year.

"The R&D of our acceleration of technology by our manufacturers was more than we anticipated." After talking with all three engine makers in November, Barnhart and Casey began to put plans into place. "They've got about five or six months and they've just responded in a great fashion to be able to be prepared to make this change for May."

Chassis changes for the Indy 500 have not yet been determined, but Barnhart did say they've got ongoing CFD [computational fluid dynamics] and wind tunnel programs. He did feel confident the League can go back to a more swept air box so that the look of Indy racers will remain the same as it has been since inception and, even more important, so that League sponsors can get more square inches to place their decals.

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Series IndyCar
Drivers Helio Castroneves , Kenny Brack , Tony Renna , Brian Barnhart