We heard and read several stories about this very special day, but it seems no one has talked to the man who was the track engineer that day.

Auto123.com recently talked with former Penske Racing engineer, Nigel Beresford, about the test drive aboard a Penske Indy Car that three-time Formula 1 World Champion, Ayrton Senna, had some 20 years ago.

“People say you should not meet your heroes, but heroes I've met such as Ayrton Senna, Rick Mears and Roger Penske, never disappointed me. Senna did not disappoint me at any level. He was just amazingly quick,” remembered Nigel Beresford, from his home in the UK.

Ayrton Senna (Photo: WRI2)

“My opinion is that Senna was extraordinarily charismatic and enigmatic, and seemed to be capable of raising his performance to a level far beyond the reach of other F1 drivers; most particularly in qualifying,” Beresford told us.

Senna had just ended the 1992 season with McLaren and was pondering his options. Beresford had just left Tyrrell one year before, after three seasons in F1, to join Penske Racing in the U.S.

“We were out to test the new Penske PC22 for three days -- one at Firebird West, a 1.1-mile road course, which really is a Mickey Mouse place -- followed by two days on Phoenix International Raceway's oval. We also had a 1992 Penske to use as a comparison car and as a baseline,” Beresford explained.

A few days before the test, an agreement was reached through Emerson Fittipaldi for Senna to drive the '92 car. “It was a last-minute deal,” Beresford confirmed.

“When Senna arrived, he was alone with John Hogan of Marlboro. It was quite a stunning contrast between the grandeur of the Australian F1 GP at Adelaide and the very basic, Mickey Mouse, kart-like track in the middle of nowhere just outside Phoenix. To see someone like him in such an ordinary place a year later still seemed surreal,” the engineer added.

Senna sitting in the Penske with the team members around him. (Original photo by Jonathan Exley)

“Emerson drove the '92 car first; it was pretty cold and the track was very slippery. He had a little spin in the cold tires, but eventually found the car pretty well balanced and just lacking overall grip. He did not push hard at all. He locked up one front tire at one point. He came in, and we changed tires, and adjusted the brake balance a bit more towards the rear. Emmo completed a 12-lap run and a 13-lap run, setting a best time of 49.70 seconds twice,” Beresford told Auto123.com.

After a short break, Senna slid into the narrow cockpit of the Penske car.

“Normally, F1 drivers get at pace immediately. Ayrton started doing some pretty slow laps initially, and that was a surprise. This car had a sequential gearbox and Senna had to get used to manipulating a gear shifter again as the F1 McLaren was fitted with paddles. On occasion, he would lose his way through the gears. He would stop completely, select first gear and then go again,” Beresford explained.

The author with Nigel Beresford at the Grand Prix of Belle-Isle in Detroit. (Photo: Philippe Champoux)

The three-time World Champion also had to get used to driving a car with a clutch pedal, a turbo engine and iron brakes.

After an initial 14 laps, he returned to the pits.

“He said the engine was very driveable, and found the car pretty heavy -- not as nimble as a much lighter Formula 1 car -- and added he did not know the revs he was pulling because the engine sounded so different.

“Firebird has one moderately quick corner, and Senna was just starting to push the car through that corner. He could feel the weight of the car. He did not want to push it to the limit. It was not the place nor the time to do it. He wanted to see the sensitivity of the car. So we put softer springs on the car and disconnected the rear anti-roll bar” Berfesford explained.

Senna did another 10-lap run on the same set of tires, and set a best time in 49.09 seconds.

“He came back into the pits and said: 'Thank you very much, I've learned what I need to know.' Then he got out of the car and that was that.”

Rick Mears driving the '92 Penske at Indianapolis. (Photo: IMS)

We asked Beresford what did he mean by that. “I think he wanted to understand how different the Indy cars were from F1 cars, nothing more,” Berfesford replied.

“Fittipaldi's best lap was a 49.70 compared to Senna's 49.09. At the end of the day, Emerson did a 48.5 in the new car, and that was just 0.6 second quicker than Senna. That was very good considering Ayrton was driving a year-old car on old tires. To me that indicated just how extraordinarily quickly he was able to adapt and approach competitive times when measured against a known, very high standard in Emerson Fittipaldi,” Beresford concluded.