| The Indy Racing League, better known as IRL, | | | | asymmetrical to account for the pull of |
| is the sanctioning body of a predominantly | | | | liquids to the right side of the cars. The |
| American based open-wheel racing series. Its | | | | current generation chassis however, are |
| centerpiece is the Indianapolis 500. The IRL | | | | designed to accommodate the added |
| is owned by Hulman and Co., which also owns | | | | requirements of road racing. Drivers report |
| the Indianapolis Motor Speedway complex. The | | | | that the cars are particularly demanding to |
| IRL was founded in 1994 by Tony George and | | | | drive on road courses, especially when |
| began racing in 1996. It was created with a | | | | compared to GP2 and Champ Car chassis. |
| breakaway group of drivers from CART, which | | | | |
| had sanctioned Indy car racing since 1979, | | | | Indy Racing League officials have confirmed |
| who incidentally, had broken away from USAC. | | | | that the series will continue to use the |
| George blueprinted the IRL as a lower-cost | | | | current batch of Dallara and Panoz chassis |
| open-wheel alternative to CART, which had | | | | for the balance of this season (2006). Both |
| come to be technology-driven and dominated by | | | | manufacturers have served as chassis |
| a few wealthy multi-car teams, much like | | | | manufacturers with the IndyCar Series since |
| Formula One. Ironically, the IRL has come | | | | 1997 and their current three-year chassis |
| full-circle and is much like the CART series | | | | suppliers' agreement was signed in 2003. The |
| it sought to separate from. The IRL is, | | | | series currently has no confirmed chassis |
| itself, dominated by a few wealthy teams, | | | | contracts for 2007. By the end of the 2006 |
| mainly consists of foreign-born drivers, and | | | | season, all full-time teams were using |
| is a mix of ovals and road/street courses. | | | | Dallaras for oval races. |
| | | | |
| The IRL developed a consistent engine package | | | | The Engines |
| and chassis rules which have produced some of | | | | |
| the closest finishes in any racing series. | | | | Starting in 1997, IRL cars were powered by |
| Ironically, the series is now dominated by | | | | 4.0L V8, methanol burning, production-based, |
| many of the same wealthy multi-car teams that | | | | normally-aspirated engines, produced by |
| once dominated CART. | | | | Oldsmobile (under the Aurora label) and |
| | | | Nissan (badged as Infiniti). That engine |
| The series initially raced exclusively on | | | | formula was replaced by a 3.5L format for |
| oval tracks, as the league was founded partly | | | | 2000, at which time the requirement for the |
| in response to the increasing prominence of | | | | block to be production-based was dropped. |
| road and street courses on the CART schedule. | | | | This formula was used through 2003. In 2004, |
| In 2005, the series abandoned its unofficial | | | | the displacement was further reduced to 3.0L, |
| ovals-only stance, and added three road | | | | in an attempt to curb top speeds. In 2006, |
| street course events (Watkins Glen, Infineon | | | | the series switched to a new fuel blend. For |
| and St. Petersburg). For 2007, two more road | | | | one season, the cars would burn a 90%/10% |
| street events (Mid-Ohio and Belle Isle) were | | | | mixture of methanol and ethanol. For 2007, |
| added. | | | | the engines will utilize a 100% ethanol fuel, |
| | | | and displacement will be increased back to |
| In its inception, the series and George | | | | 3.5 L. |
| himself were widely ridiculed by members of | | | | |
| the media and some CART competitors. The | | | | Historically, Honda, Toyota and Chevrolet |
| IRL's early seasons consisted of sparse | | | | competed for the engine supply business. In a |
| schedules, mostly unknown drivers, and | | | | major development announced by Chevrolet on |
| novice-level teams, even in the Indy 500. | | | | November 4 2004, Chevrolet stated that it |
| Eventually the schedule expanded, and caliber | | | | would be ending its IRL engine program |
| of drivers improved. The IRL began to draw | | | | effective with the end of the 2005 season, |
| teams from CART starting in 2000, | | | | citing costs that exceeded value, according |
| contributing to the latter's bankruptcy in | | | | to then-GM Racing Director Doug Duchardt. |
| 2003. | | | | "The investment did not meet our objectives," |
| | | | he was quoted as saying. In November 2005, |
| The League consists of two series, the | | | | Toyota company officials announced the |
| premiere IndyCar Series (usually considered | | | | company's withdrawal from American open-wheel |
| synonymous with the Indy Racing League) and | | | | racing and the immediate discontinuation of |
| the Indy Pro Series, which is a developmental | | | | its IRL program. The company in the past |
| series. | | | | stated a dissatisfaction with the investment |
| | | | returns in the series, and at the same time, |
| The Cars | | | | Toyota Racing Development is preparing for |
| | | | entry into the NASCAR Nextel Cup Series in |
| IRL is not an open formula, but neither is it | | | | 2007. This has left Honda as the sole engine |
| a one-make or "spec" series. Instead, chassis | | | | supplier to the IRL through 2009. Whether |
| and engine manufacturers apply to the League | | | | this constitutes a serious blow to the series |
| to supply cars for three year cycles. | | | | or just another change remains to be seen. |
| Currently, Dallara and Panoz provide the | | | | |
| chassis, while Honda is the sole engine | | | | Currently, IRL engines are rev-limited to |
| provider. A third chassis manufacturer, | | | | 10,300 rpm and produce approximately 750 hp |
| Falcon, once held the rights to produce a | | | | at that revolution regime. The Honda HI5R |
| chassis for IRL events, but as no orders were | | | | engine is a normally aspirated, |
| ever made, no Falcon IRL rolling chassis were | | | | fuel-injected, aluminum alloy cylinder block |
| ever completed, and the company has since | | | | V-8 with a displacement of 3.0 liters (183.1 |
| ceased to exist. Riley & Scott produced IRL | | | | in3). The valve train is a dual overhead |
| chassis from late 1997 to 2000. In the | | | | camshaft configuration with four valves per |
| series' first season, 1996, old CART chassis | | | | cylinder. The crankshaft is made of alloy |
| were used. | | | | steel, with five main bearing caps. The |
| | | | pistons are forged aluminum alloy, while the |
| Superficially, IRL cars closely resemble | | | | connecting rods are machined alloy steel. The |
| those of other open-wheeled formula racing | | | | electronic engine management system is |
| cars, with front and rear wings and prominent | | | | supplied by Motorola, firing a CDI ignition |
| airboxes. Originally, the cars were unique, | | | | system. The engine lubrication is a dry sump |
| being designed specifically for oval racing; | | | | type, cooled by a single water pump. |
| for example, the oil and cooling systems were | | | | |