The Penske PC-23 was designed by Nigel Bennett, who based its design on the 1993 car, the PC-22, which was a radical departure from the basic concept of the previous Penske cars. The PC-23 was one of the most dominant open wheel race cars ever developed.
The only substantial difference of the new car 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 PC23 equipped with twin-cam Ilmor V8 265D engine, 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, 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.
In the 1995, the Bettenhausen Motorsports team used the PC-23 for almost the entire season, with the Indy 500 and Milwaukee as sole exceptions. Bettenhausen driver Stefan Johansson scoredpoints in eight races and finished a 13th place in the final standings, with one third place as its best result.
In 1996, the PC-23 had one final run, at the inaugural U.S. 500 with Gary Bettenhausen, who crashed out of the race in lap 89, while in the 21st place.
Nevertheless, the car is mostly known for the controversial pushrod Mercedes-Benz 500I engine, designed and developed for the single race of Indianapolis.
Even when he was still driving himself, Roger Penske always carefully searched through the rulebooks for loopholes in a quest to gain what is now famously known as the ‘Unfair Advantage’. There are examples abundant like his single-seater Zerex Special sports car, the Trans-Am Javelins with Porsche 917 brakes or the all-conquering Porsche 917/30. His finest hour, however, came at the 1994 Indy 500 for which Penske equipped his cars with an engine that bent the rules very close to the breaking point.
At that time, the Indy 500 was not part of the CART Championship and sanctioned by the United States Auto Club (USAC). The regulations were very similar, so the teams could field the same cars but there were some small differences in the engine compartment. With an eye on attracting more American manufacturers the traditional ‘stock-block’ was slightly favoured by allowing push-rod engines to run with a larger displacement and at higher turbo boost levels. This often allowed the Buick-engined cars to steal the thunder during qualifying but they rarely managed to complete all 200 laps.
Also, 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 turbocharge boost (55 inHG vs. 45 inHG).
For several years Team Penske had sourced their engines from the part-owned British engineering firm Ilmor. Up until 1994 these V8 engines were labelled Chevrolet but as the American company dropped its support, they were simply known as Ilmors during the regular season.
What was omitted in the regulations was the requirement that this push-rod engine actually had to be based on a stock-block. The rule makers had probably figured that no team or manufacturer could spend the vast resources required to purpose build an engine using a principle that had long been considered outdated in racing circles. With Roger Penske around, they perhaps should have known better. The Ilmor maker figured that a clean-sheet, carefully-designed pushrod engine could take advantage of the regulatory loophole to overcome its inherent design disadvantages compared to a multi-valve engine, and thus trounce the competition for at least one race before the powers-that-be cracked down on the rulebook’s oversight.
A little-known fact about Penske Racing´s planning for the future was that already in 1992 there had been talk about building a pushrod. The 1992 ‘500’ had become a fiasco for Penske and right after the race the team held a meeting in one of the garages within Gasoline Alley to discuss what had gone wrong. One of the things that had been noticed by the team was the outrageous speeds of the fastest Buicks, supporting the potential of the stock-block V6 with its higher turbo boost and larger capacity. Mario Illien, also present at that meeting, then suggested that Ilmor could build a purpose-designed pushrod engine. Despite a lot of interest by Roger Penske for this idea, nothing happened with it in time to have such an engine in 1993.
In late May 1993 Ilmor and Penske made up the plans for 1994, one of those being the development of a new quadcam: the 265D. Illien then suggested to Penske that Ilmor design and build a pushrod V8 for Indy. Illien feared the results for his engines if another engine builder would come up with a purpose-design pushrod V8 and in order to counteract such an attack, he wanted to have one built by Ilmor. So he did some homework and suggested to Roger Penske that Ilmor had to build a pushrod. When Penske asked what kind of power such an engine could provide, Illien told him it was to be about 940hp.
Once it became obvious to Roger Penske that such an engine would have a power advantage of 150hp or more he became highly interested in the project, especially since the modified corners had made the straights more important than ever as the place to overtake. However, that would mean building two entirely different cars for the ’94 season, something that was even beyond the financial capacities of Team Penske, so when Mario Illien promised to build Penske a pushrod V8 that was exactly the same length as the new-for-1994 quadcam (thus making it possible to change the type of engine within the very same chassis) he got the green light to go ahead with a secret project that was to shock the racing world.
One of Ilmor’s other customers was Mercedes-Benz, for which they designed and constructed the V10 F1 engine in 1993 mounted on Mercedes-Benz Sauber C12 (3.5L V10 Ilmor engines 730HP and a red limit at 14.000 rpm) and in 1994 on Mercedes-Benz Sauber C13 (3.5L V10 Ilmor engine with 735HP).
Penske and Ilmor proposed the idea of the special Indy engine to Mercedes-Benz and they were very keen to get a piece of the Indy cake despite the huge costs involved.
Mercedes-Benz 500I Engine
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. Constructed from light alloys, the V8 featured the same 82º V-angle as Ilmor’s familiar engine. The increased displacement limit for push-rod engines was just over 3.4 litre compared to the 2.65 litre of a twin-cam unit. As prescribed by the regulations, it came equipped with a single, centrally mounted camshaft that actuated the valves through push-rods. With the Garrett turbo running at 1.86 bar (55 inch Mercury), the 500I produced a staggering 1024 bhp, giving Team Penske a 200 bhp ‘Unfair Advantage’.
The first tests with a 265E engine took place at the end of January ’94. 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. Penske’s US workshop was located in Reading, PA. Adjacent to the building there was another business building, owned by Penske Truck Leasing. A very small group of engine engineers led by Kevin Walter built a completely separate, secret workshop (known as the “Taj Mahal”) in one of the buildings on the terrain. The engines were built up there. Testing them on the dyno however was done in secret in the main building during the night. The engines were run until they broke so the weak points were discovered. The employees who arrived in the morning found out to their surprise that the water of the dynomometer was still warm.
One month later the first tests with an engine installed in a car took place, at the Nazareth Speedway, owned by Roger Penske. At that time the project was still carried out in the utmost secrecy but now there was the risk of the secret coming out. The Andretti family lived in Nazareth and if by chance Mario found out about the tests at the track and heard the engine noise, he might understand what was going on. Fortunately for Penske and Ilmor, Mario was out skiing.
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.
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.
Starting from 25th, Tracy was again the first Penske driver to hit problems when a turbocharger failure forced him to retire early. The remaining Mercedes engined Penskes dominated the event and led all but seven laps of the race. Fittipaldi had the upper hand and while trying to lap Unser, who was in second, he hit a rumble-strip and spun into the barrier. Fortunately Unser made no mistakes and his PC23 survived unscathed to score what Roger Penske later called his favourite victory in the Indy 500.
With the Ilmor/Mercedes 500I engine, illegal in the CART championship, Penske had to revert back to the more conventional twin-cam Ilmor V8.
The car in its Indy 500 version caused a considerable uproar at the Indianapolis Motor Speedway and in the racing world in general. Subsequently, the PC-23 was recognized as one of the triggers of the CART/IRL split, which did huge damage to both series, to the following Champ Car (NASCAR exploited the situation to grow as the most popular racing series in US), and to today’s again-unified IndyCar Series, which don’t have the international appeal, nor the technical advance that the CART enjoyed in early 1990s. The PC-23 influenced subsequent rule making at Indianapolis.
For a more in-depth look at the engine and the racing politics that surrounded it, check out this 8W article.
Not surprisingly, the regulations were changed at the end of the year and Team Penske could not use the special Indy engine again. It had nevertheless helped crown an utterly dominant year for the team. Perhaps even more importantly, it had helped attract Mercedes-Benz into the fray and from 1995 onwards the Ilmor engines were rebadged Mercedes-Benz.
Chassis PC23/007 was the seventh of nine Penske PC23s constructed for the 1994 season. Fitted with the Mercedes/Ilmor 500I engine, it was driven to victory in the Indy 500 by Al Unser Jr. Like most of Team Penske’s Indy winning racers, it was retained by Roger Penske. Chassis 7 has been preserved in its Indy winning configuration and was one of the stars of the Indy centenary celebrations during the 2011 Goodwood Festival of Speed. It was driven by former legendary Penske racers like Emerson Fittipaldi and Helio Castroneves.
8. The C111 design study was originally baptized , the C101 project. However, the “0 (zero)” in the middle had to disappear , since this number combination has long been protected by....
Dec 15 2014
1994 Penske-Mercedes PC23 IndyCar
The race-car that changed everything…
The Penske PC-23 was designed by Nigel Bennett, who based its design on the 1993 car, the PC-22, which was a radical departure from the basic concept of the previous Penske cars. The PC-23 was one of the most dominant open wheel race cars ever developed.
The only substantial difference of the new car 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 PC23 equipped with twin-cam Ilmor V8 265D engine, 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, 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.
In the 1995, the Bettenhausen Motorsports team used the PC-23 for almost the entire season, with the Indy 500 and Milwaukee as sole exceptions. Bettenhausen driver Stefan Johansson scoredpoints in eight races and finished a 13th place in the final standings, with one third place as its best result.
In 1996, the PC-23 had one final run, at the inaugural U.S. 500 with Gary Bettenhausen, who crashed out of the race in lap 89, while in the 21st place.
Nevertheless, the car is mostly known for the controversial pushrod Mercedes-Benz 500I engine, designed and developed for the single race of Indianapolis.
Even when he was still driving himself, Roger Penske always carefully searched through the rulebooks for loopholes in a quest to gain what is now famously known as the ‘Unfair Advantage’. There are examples abundant like his single-seater Zerex Special sports car, the Trans-Am Javelins with Porsche 917 brakes or the all-conquering Porsche 917/30. His finest hour, however, came at the 1994 Indy 500 for which Penske equipped his cars with an engine that bent the rules very close to the breaking point.
At that time, the Indy 500 was not part of the CART Championship and sanctioned by the United States Auto Club (USAC). The regulations were very similar, so the teams could field the same cars but there were some small differences in the engine compartment. With an eye on attracting more American manufacturers the traditional ‘stock-block’ was slightly favoured by allowing push-rod engines to run with a larger displacement and at higher turbo boost levels. This often allowed the Buick-engined cars to steal the thunder during qualifying but they rarely managed to complete all 200 laps.
Also, 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 turbocharge boost (55 inHG vs. 45 inHG).
For several years Team Penske had sourced their engines from the part-owned British engineering firm Ilmor. Up until 1994 these V8 engines were labelled Chevrolet but as the American company dropped its support, they were simply known as Ilmors during the regular season.
What was omitted in the regulations was the requirement that this push-rod engine actually had to be based on a stock-block. The rule makers had probably figured that no team or manufacturer could spend the vast resources required to purpose build an engine using a principle that had long been considered outdated in racing circles. With Roger Penske around, they perhaps should have known better. The Ilmor maker figured that a clean-sheet, carefully-designed pushrod engine could take advantage of the regulatory loophole to overcome its inherent design disadvantages compared to a multi-valve engine, and thus trounce the competition for at least one race before the powers-that-be cracked down on the rulebook’s oversight.
A little-known fact about Penske Racing´s planning for the future was that already in 1992 there had been talk about building a pushrod. The 1992 ‘500’ had become a fiasco for Penske and right after the race the team held a meeting in one of the garages within Gasoline Alley to discuss what had gone wrong. One of the things that had been noticed by the team was the outrageous speeds of the fastest Buicks, supporting the potential of the stock-block V6 with its higher turbo boost and larger capacity. Mario Illien, also present at that meeting, then suggested that Ilmor could build a purpose-designed pushrod engine. Despite a lot of interest by Roger Penske for this idea, nothing happened with it in time to have such an engine in 1993.
In late May 1993 Ilmor and Penske made up the plans for 1994, one of those being the development of a new quadcam: the 265D. Illien then suggested to Penske that Ilmor design and build a pushrod V8 for Indy. Illien feared the results for his engines if another engine builder would come up with a purpose-design pushrod V8 and in order to counteract such an attack, he wanted to have one built by Ilmor. So he did some homework and suggested to Roger Penske that Ilmor had to build a pushrod. When Penske asked what kind of power such an engine could provide, Illien told him it was to be about 940hp.
Once it became obvious to Roger Penske that such an engine would have a power advantage of 150hp or more he became highly interested in the project, especially since the modified corners had made the straights more important than ever as the place to overtake. However, that would mean building two entirely different cars for the ’94 season, something that was even beyond the financial capacities of Team Penske, so when Mario Illien promised to build Penske a pushrod V8 that was exactly the same length as the new-for-1994 quadcam (thus making it possible to change the type of engine within the very same chassis) he got the green light to go ahead with a secret project that was to shock the racing world.
One of Ilmor’s other customers was Mercedes-Benz, for which they designed and constructed the V10 F1 engine in 1993 mounted on Mercedes-Benz Sauber C12 (3.5L V10 Ilmor engines 730HP and a red limit at 14.000 rpm) and in 1994 on Mercedes-Benz Sauber C13 (3.5L V10 Ilmor engine with 735HP).
Penske and Ilmor proposed the idea of the special Indy engine to Mercedes-Benz and they were very keen to get a piece of the Indy cake despite the huge costs involved.
Mercedes-Benz 500I Engine
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. Constructed from light alloys, the V8 featured the same 82º V-angle as Ilmor’s familiar engine. The increased displacement limit for push-rod engines was just over 3.4 litre compared to the 2.65 litre of a twin-cam unit. As prescribed by the regulations, it came equipped with a single, centrally mounted camshaft that actuated the valves through push-rods. With the Garrett turbo running at 1.86 bar (55 inch Mercury), the 500I produced a staggering 1024 bhp, giving Team Penske a 200 bhp ‘Unfair Advantage’.
The first tests with a 265E engine took place at the end of January ’94. 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. Penske’s US workshop was located in Reading, PA. Adjacent to the building there was another business building, owned by Penske Truck Leasing. A very small group of engine engineers led by Kevin Walter built a completely separate, secret workshop (known as the “Taj Mahal”) in one of the buildings on the terrain. The engines were built up there. Testing them on the dyno however was done in secret in the main building during the night. The engines were run until they broke so the weak points were discovered. The employees who arrived in the morning found out to their surprise that the water of the dynomometer was still warm.
One month later the first tests with an engine installed in a car took place, at the Nazareth Speedway, owned by Roger Penske. At that time the project was still carried out in the utmost secrecy but now there was the risk of the secret coming out. The Andretti family lived in Nazareth and if by chance Mario found out about the tests at the track and heard the engine noise, he might understand what was going on. Fortunately for Penske and Ilmor, Mario was out skiing.
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.
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.
Starting from 25th, Tracy was again the first Penske driver to hit problems when a turbocharger failure forced him to retire early. The remaining Mercedes engined Penskes dominated the event and led all but seven laps of the race. Fittipaldi had the upper hand and while trying to lap Unser, who was in second, he hit a rumble-strip and spun into the barrier. Fortunately Unser made no mistakes and his PC23 survived unscathed to score what Roger Penske later called his favourite victory in the Indy 500.
With the Ilmor/Mercedes 500I engine, illegal in the CART championship, Penske had to revert back to the more conventional twin-cam Ilmor V8.
The car in its Indy 500 version caused a considerable uproar at the Indianapolis Motor Speedway and in the racing world in general. Subsequently, the PC-23 was recognized as one of the triggers of the CART/IRL split, which did huge damage to both series, to the following Champ Car (NASCAR exploited the situation to grow as the most popular racing series in US), and to today’s again-unified IndyCar Series, which don’t have the international appeal, nor the technical advance that the CART enjoyed in early 1990s. The PC-23 influenced subsequent rule making at Indianapolis.
For a more in-depth look at the engine and the racing politics that surrounded it, check out this 8W article.
Restauration on chassis number 8 right HERE.
Not surprisingly, the regulations were changed at the end of the year and Team Penske could not use the special Indy engine again. It had nevertheless helped crown an utterly dominant year for the team. Perhaps even more importantly, it had helped attract Mercedes-Benz into the fray and from 1995 onwards the Ilmor engines were rebadged Mercedes-Benz.
Chassis PC23/007 was the seventh of nine Penske PC23s constructed for the 1994 season. Fitted with the Mercedes/Ilmor 500I engine, it was driven to victory in the Indy 500 by Al Unser Jr. Like most of Team Penske’s Indy winning racers, it was retained by Roger Penske. Chassis 7 has been preserved in its Indy winning configuration and was one of the stars of the Indy centenary celebrations during the 2011 Goodwood Festival of Speed. It was driven by former legendary Penske racers like Emerson Fittipaldi and Helio Castroneves.
https://www.youtube.com/watch?v=G5b8HHnh3lk
By Catalin Varvara • MB MotorSports, Penske 0 • Tags: 1994 penske, benz, Mercedes, mercedes 1994, mercedes-benz, penske, penske pc23