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