IMSA 1990 retrospective: Jags punish the Sunbank 24 field

Image courtesy Daytona International Speedway

IMSA 1990 retrospective: Jags punish the Sunbank 24 field

Vintage Motorsport / Historic

IMSA 1990 retrospective: Jags punish the Sunbank 24 field

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If today’s flat-out style of Rolex 24 At Daytona racing has an author, it was surely the Tom Walkinshaw Racing USA team and its gorgeous Jaguar XJR-12Ds as they turned in a crushing performance over the Feb. 3-4 weekend 30 years ago.

Baked in heat, drenched in Florida’s notorious humidity, the 1990 Sunbank 24 Hours of Daytona saw the first use of torrid, unflinching pace to win the contest. In what’s become standard practice today, where the entire field pushes to the limit for all 24 hours, the ’90 event featured a break from tradition where conserving the car for the first 20 hours was the standard plan in every pit stall.

Led by TWR team manager Tony Dowe, and chief engineer Ian Reed, the V12-powered Jags drew upon the considerable reliability advantage its naturally-aspirated Grand Touring Prototypes enjoyed over their turbocharged rivals.

By 1990, the twin-turbo V6 factory Nissan GTP-ZX Ts had won back-to-back championships, but a Daytona win was proving elusive. All American Racers was in the early stages of its GTP program with the four-cylinder turbo Toyota HF89, and even the bulletproof Porsche 962s, nearing the end of their competitive lifespan, were fast but on edge as teams wrung every drop of performance from the turbocharged flat-six motors.

“We were in the process of trying to build and develop the current V6 turbo [XJR-10],” Dowe said in a call from his adopted home in Australia. “And, so, the budgets were going turbo, rather than the V12. Having said that, one of the things we always made a big effort at Daytona, it’s fairly obvious, right from the beginning, that while we were racing a car that fitted the rules, we weren’t racing a car that was built to win in any. A lot of people within my world might take exception to that, but when you looked at what Nissan were able to do with turbos and downforce, and the tires they were running, it made it very hard.”

The punishing tempo set by the No. 61 piloted by Davy Jones, Jan Lammers, and Andy Wallace, and the sister No. 60 XJR-12D driven by Martin Brundle, Price Cobb, and John Nielsen would prove to be the winning formula.

Davy Jones, Jan Lammers and Andy Wallace celebrate after 24 grueling hours. Image courtesy Daytona International Speedwat

“Well, you go to Daytona just knowing that you have the best team in every way,” Jones said of the crack TWR team that was based out of Valparaiso, Indiana. “You’ve got all the support to win that race. And it was ours to lose. The 962 Porsches had been so dominant for so many years. We knew that with the XJR-12 that that was our mule, that was our workhorse. We opted to go with the V12 just because it was bulletproof. They were reliable, and when you go into a race weekend knowing that you have the best of the best, it sets that mindset straight out.”

Coming into the weekend, 61 cars were ready to take part in practice and qualifying. Around the 3.56-mile road course and oval, which had none of the overhead lighting that makes life easy for modern drivers, clashes and attrition would await the deep field of GTPs, GTP Lights, GTOs, and GTUs.

In qualifying, the Nissans were met with a surprise as a highly developed No. 86 Bayside Porsche 962, with trick new aerodynamics dressed in the black colors of Texaco, snatched pole position with a lap of 1m37.8s. Nissan was close with the No. 84 GTP ZX-T turning a 1m37.9s lap to start second, and the No. 83 wasn’t far away in fourth. The best of the TWR Jags would line up ninth, with the No. 60 a full 2.5 seconds slower than the pole-winning Porsche. The No. 61 would post the 10th-fastest lap, 2.8 seconds off the Bayside 962, in the GTP class that sent 15 cars to take the start.

“Yeah, that time was our race time,” Dowe said. “That qualifying time was what we could race at. That was pretty much where we were going to be, so we weren’t sweating.”

Without turbos to boost the Jag’s 6.0-liter V12s, Jones was unfazed by losing the qualifying battle.

The Jaguars were well off the pole-winning pace, but could run for 24 hours at their qualifying speed. Image by Marshall Pruett.

“We didn’t have the opportunity to turn up the boost and go for an all-out qualifying run just to be on the front row,” he said. “We had what we had. All you can do for qualifying is put new rubber on and lighter fuel tanks and maybe trim it out a little bit and piece together your best lap. You’re going to go there and you’re going to qualify up front, or you’re going to qualify somewhere in the top 10 is where you want to be.

“And then after the race settles out after the first hour or two, generally you’re setting the race pace that you want. (The others) went out and set qualifying times and put those laps together. We just continued our same pace from when we arrived, first practice all the way through to the race end. And we just focused on that.”

Jaguar’s winning debut at the 1988 Daytona 24 Hours and strong run at the 1989 race came with Dunlop rubber mounted to the cars. A popular solution in Europe and Japan, the Dunlops were losing ground to Goodyear as the 1989 season wore on, and, with its closest competitors using the American tires, TWR joined them in 1990. At Daytona, the XJR-12Ds were reborn under braking, in the corners, and while accelerating with the added grip and consistency the Goodyears offered.

“It settled the whole car down,” Jones confirmed. “The Dunlop tires, we had good tires, we had mediocre tires. We knew the tires that we received from Japan were okay tires. The tires that we received from the U.K. were better tires. But they had really super stiff sidewalls. When we put the Goodyears on, straight away it settled the whole car down. The car wasn’t as nervous. It allowed the whole tire, the sidewall, the absorption, the grip, everything to work better and last longer for us.”

Once the green flag waved, sports car legend Bob Wollek disappeared from the head of the field in the Bayside 962. A broken fitting that fed oil one of the turbos on the 3.0-liter Porsche motor in the second hour would cost the team nine laps as repairs were made. Lapping at or near the low 1m40s times they turned in qualifying, the Nos. 60 and 61 Jags began marching forward as many of their closest threats dialed down the boost with hopes of making it to the finish.

“From our point of view, once Bob was out (of contention) with his car, we were racing ourselves the whole way,” Dowe said. “There is some awesome film of Brundle and Lammers swapping positions on the banking coming out of NASCAR 1 and 2, and I had to get on the phone and say, “Look, guys, we’re only five hours into this race; we need to keep our heads on.”

By the halfway point, both Nissan turbos were out. Image by Marshall Pruett

Following the Bayside Porsche mechanical drama, the race exposed reliability issues in other GTP models as midnight arrived. By the halfway point of the 24-hour race, both Nissans were done, the AAR Toyota was out, and even a few Porsche 962s were retired with blown engines or accidents conspiring against success.

The lone privateer Nissan, entered by Busby Racing, was also struck by misfortune when its engine exploded, leaving the XJR-12Ds to hammer away without interruption.

“When you have an endurance race, we were, as a team, able to have really good drivers, and really good teamwork,” Dowe said. “That’s not putting any other team down, but we did put a big effort into that. We always felt the Nissan V6 was going to be fragile over 10, 12 hours, which proved to be the case. I mean, they only managed to win when they used the Group C car. They could do 12 hours at Sebring, but after that they became fairly marginal.”

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