The PC-23 was a design evolution of its predecessor, the PC-22, which won the 1993 Indianapolis 500, 8 races over the entire season, and missed the 1993 CART title by only 8 points. The only substantial difference of the new car from it were the smaller rear wings on the short ovals, mandatory by rule changes for the 1994 season, and Team Penske put in a lot of test efforts to minimize the effects of these changes. There were also some modifications on the transmission, but the new car was mostly an progression. Plans to fit the PC-23 with an active suspension system were canceled due to a ban by CART on such technology. The car and the Ilmor engine were ready for testing by mid December 1993.
The Indy 500 version of the PC-23, showed a much higher engine cover, required because of the new engine. Other modifications included changes to the input gears of the gearbox, to cope with the lower rpm and higher power and torque the pushrod engine provided. However, the two versions of the gearbox were of the same weight, thus causing no shift in the weight balance. The Mercedes-Benz 500I engine was slightly lighter than the Ilmor Indy V8, although because of its longer inlets the center of gravity of the entire engine was higher than that of the 500I, thus changing the overall balance of the car a bit. The development and testing of the 500I engine, at that time called Ilmor 265E, took place in the utmost secrecy, because there was a possibility of the turbocharger boost level being changed, or the engine being banned by the Indy 500 sanctioning body.
Much to the surprise of competitors, media, and fans, Marlboro Team Penske arrived at the Indianapolis Motor Speedway with a brand new, secretly-built 209 cid Mercedes-Benz pushrod engine, which was capable of a reported 1000 horsepower. Despite reliability issues with the engine and handling difficulties with the chassis, the three-car Penske team (Unser, Emerson Fittipaldi and Paul Tracy) dominated most of the month, and nearly the entire race. This engine used a provision in the rules intended for stock block pushrod engines such as the V-6 Buick engines that allowed an extra 650 cm³ and 10 inches (4.9 psi/33.8 kPa) of boost. This extra power (at least 900 horsepower, and rumored to be in excess of 1000 hp, which was up a 150-200 hp advantage over the conventional V-8s.) allowed the Penskes to run significantly faster, giving them the pole and outside front row on the grid for the 78th Indianapolis 500. Al Unser, Jr. and Emerson Fittipaldi dominated the race, eventually lapping the field with 16 laps to go in the 200 lap race when Emerson made contact with wall coming out of Turn 4, giving Al Unser, Jr. the lead and win. The only other driver who finished on the lead lap was rookie Jacques Villeneuve.
In the summer and fall of 1993, Ilmor and Penske engaged in a new engine program. Under complete secrecy, a 209-cid purpose-built, pushrod engine was being developed. Mercedes took over the project, and dubbed the engine the Mercedes-Benz 500I. The engine was designed to exploit a perceived "loophole" that existed in USAC's rulebook since 1991. While CART sanctioned the rest of the Indycar season, the Indianapolis 500 itself was conducted by USAC under slightly different rules.
In an effort to appeal to smaller engine-building companies, USAC had permitted "stock-block" pushrod engines (generally defined as single non-OHC units fitted with two valves per cylinder actuated by pushrod androcker arm). The traditional "stock blocks," saw some limited use in the early 1980s, but became mainstream at Indy starting with the introduction of the Buick V-6 Indy engine. Initially, the stock blocks were required to have some production-based parts. However in 1991, USAC quietly lifted the requirement, and purpose-built pushrod engines were permitted to be designed for racing at the onset. Attempting to create an equivalency formula, both pushrod engine formats were allowed increased displacement (209.3 cid vs. 161.7), and increased turbocharger boost (55 inHG vs. 45 inHG).
Team Penske mated the engine with the in-house Penske chassis, the PC-23. It was introduced to the public in April, just days before opening day at Indy.
The PC23 debuted at 1994 Australian FAI Indycar Grand Prix, noted for the sensational debut win of Reynard chassis, qualifying 3rd with Fittipaldi, 5th with Al Unser, Jr. and 6th with Tracy. In the race, which was shortened by 10 laps due to darkness, Fittipaldi scored a 2nd place, while Unser and Tracy retired for electrical problems. At Phoenix, the first oval race of the season, the PC23 scored its first win, with Fittipaldi ahead of Al Unser, Jr. The season continued with six wins in a row, three for Unser: Long Beach,Indianapolis and Milwaukee, where Penske Racing scored a remarkable 1-2-3 win with Fittipaldi second and Tracy third, a win for Tracy at Detroit, and two wins for Unser at Portland, another 1-2-3 sweep for Penske, and Cleveland. In Toronto however, Unser's engine blew, while Fittipaldi finished 3rd, and Tracy 5th, ending an astonishing streak of seven wins in a row. In Michigan, the entire Penske pack retired, but for the next two races, Mid-Ohio and New Hampshire, the Penskes scored two 1-2-3 wins in a row, with Unser as winner on both occasions. Unser won also in Vancouver, completing his second row of 3 back to back wins of the season. The Road America was won by then rising star Jacques Villeneuve, in his first in CART racing, while Unser clinched the championship ahead of Fittipaldi. Two final events of the season, Nazareth and Laguna Seca were won by Paul Tracy. Unser, Fittipaldi and Tracy, ended the season at first three places in season standings respectively.
Weight: 703 Kg
