GTP: Wheels Of Fortune

They were the wheel of choice in the IMSA GTP series and remain the wheel of preference today in the American Le Mans Series. What started as an original equipment supplier association with Porsche’s GTs and Prototypes turned into one of the few common threads of the most diverse sportscar series of the seventies, eighties, and nineties.

Cars, teams, and drivers changed, but look across the various history books about the IMSA series, and BBS wheels were the dominant choice from Porsche 935 to the Toyota Eagle Mk III.

I first fell in love with the look of BBS wheels with those 935s; the gold, webbed wheel centers were dramatic; they looked equally as fast at rest as in motion. If other wheel manufacturers only cared about low weight and high strength, BBS recognized that aesthetics were equally important.

They ticked all the boxes for lightness and durability, so why not go the extra step to design wheels that looked less like appliances and more like pieces of art? Why not sell a wheel that complimented the flowing likes of a sportscar.

In America, BBS had (and still has) John Slagle and Craig Donnelly to thank for supporting the burgeoning IMSA series when it transitioned from a well kept secret into the monster series that dominated its era.

For Donnelly, a BBS employee since January 1st, 1980, and Slagle, rescued from the road car division in early ’86, the days supporting GT and GTP racing came less by choice and more by necessity.

“Back at that time we had a lot of the guys that came into the GTP cars were coming out of the 935 Porsches,” said Donnelly, “they were Group C cars from Europe which, obviously, BBS had already been making wheels for. And a lot of the car manufacturers that were based in England like March and Lola; we had relationships with that we just continued those relationships here with already existing teams that we were servicing.

“But because we were doing racing service and we were already at 20 plus events a year, there really wasn’t anyone else that was as visible. So it made it pretty easy to build our brand in IMSA.”

Slagle landed at BBS at a time where the quality of their wheels stood out in the series. “One of the things I think that was important in that era was that if you really looked at it, as those cars evolved there weren’t many wheel manufacturers that they could go to. You can either use a one-piece wheel manufacture like Dymag or Speedline but they were very expensive then; they weren’t very service friendly. And BBS became, especially in the States, the trusted wheel supplier because the supply of once-piece wheels here was very difficult.”

Once BBS became established as ‘the wheel’ to have, sportscar manufacturers began to lean on the Braselton, GA operation to manufacture lighter and stronger units. As downforce spiked and lightweight chassis construction materials became popular, wheels went from being an afterthought to a major area of performance to exploit. As BBS modified their wheels to keep pace with the rampant development in wind tunnels and autoclaves, their rivals tried to attract BBS’ customers with promises of better wheels. Donnelly recalls it didn’t always go as smoothly as their competitors had hoped.

“Teams were always looking for that edge. So there were guys that would bring in some stuff from Europe here to race on. And they would fail here because the racing conditions in America, on our tracks, especially in GTP, was much different than Group C in Europe, which were tabletop-smooth race tracks. Where in this country, we were brutalizing stuff on these cars here. Plus the GTP cars would run with downforce, I think, that had developed way beyond what they were doing for that in Europe. So we saw situations even on our products here, we saw stress factors in North America that they did not see in Europe.

“We were giving feedback to BBS Germany to develop parts at a faster rate; as cars developed, tires improved, suspensions improved, aerodynamics improved, more downforce – then you have to also upgrade wheels to deal with the additional stress. And this is a standard thing that you do throughout the evolution of certain racing series. But with this, we were the ones pushing that to Europe, not Europe saying this is the latest spec stuff for us to use.”

Donnelly would grow accustomed to a difference in opinions between BBS Germany and BBS USA. “The term ‘Heavy American Air’ became kind of a standard when we were discussing things with the Germans then. Because we were giving them stress and downforce load numbers like nothing they were seeing in Group C, they said it was all due to the heavy American air, which created more downforce and more stress and all this. That was kind of humorous.”

The fallacy of ‘Heavy American Air’ would come to light in 1992 at Road Atlanta when both Nissan GTP cars suffered spectacular tire failures resulting in gravity defying barrel rolls. The sheer violence of both incidents actually helped Donnelly and Slagle to get their parent company’s attention.

“Fortunately, Goodyear found out about the ‘Heavy American Air’ with the Nissans,” Slagle said. “After those crashes I think Germany had a greater respect for what we were trying to deal with because Nissan admitted to Goodyear that the downforce numbers they supplied them were inaccurate. It shed a whole different light on what we were dealing with and made Germany sit up and listen when we told them our cars had greater needs than what they were used to.”

Decades after their first involvement in the IMSA series, the two men can’t help but wax nostalgic about the times and the cars. Their look back into the series also reminded Slagle that while times have changed, many things have stayed the same.

“When you compare it to today, the funds were so much lower, the cars were really cool. Competition was fabulous. But it was much more low key in that one team could party with the other team and things of that nature. But from the work aspect, when I look back on it, it’s really kind of comical because we would pull up in a minivan that we rented and we’d be back there schlepping wheels. We didn’t even have an air gun to assemble or disassemble wheels; we were taking them apart with a speed handle!

“And it’s really funny because everybody used to laugh: you’re back here in a rental car fixing wheels – and yet last year I was in Salt Lake City for the Rolex finale and we were doing virtually the same thing! Okay, we have a Snap-on air ratchet now but in a lot of ways things hadn’t really changed. The products changed and evolved but a certain part of it really hasn’t. I can’t remember who it was, somebody was laughing, ‘You’ve been doing this for like 20-something years, we thought you’d change.’ And I think back on it and yeah, it’s been over 20 years. And we’re still doing it…”

GTP cars – no matter the manufacturer — were usually found on gold BBS wheels. The color was a perfect fit for the various cars they were fitted to, but as Donnelly recalls, it wasn’t a choice.

“Gold. Standard BBS color. Everything was gold. There were no 962s that I know of that ever left that shop other than gold. I don’t think we even did black…you could have pretty much any color as long as it was gold…”

If gold was the traditional color, the cross-spoked wheel design was also a BBS trademark. “You know, that cross-spoke design was spawned out of a number of different racing center ideas but at that time it had the best stiffness-to-weight ratio of anything going,” Donnelly offered. “The only thing you could compare it to, weight wise and was lighter, were the trick Speedline monoblocs that were hollow-spoked.

“Our wheel centers actually had hollow chambers inside. They use a loss type system in the casting and you’d actually have a hollow chamber inside there. It even had a Porsche part number on the wheel center. It was a 956 part number in those days. But it was definitely developed with Porsche directly. We used that technology for years to come with our customer products in GTP, and a lot of other companies tried to copy them with little success.”

Another unique visual from the GTP days were ‘wheel fans,’ first seen on Porsches (that I can recall) and soon requested by the majority of BBS’ clients. Donnelly found most GTP teams were trying to keep up with each other, asking BBS to sell them what they’d seen on their rivals cars without always understanding if it would help or hinder their own cars.

“The fans were really kind of comical because in some cars, depending on the aero package that they ran, they didn’t work at all,” said Slagle. “It became a bit of a game, especially – I know we’re talking about GTPs but we were so prominent in Trans Am and IMSA GTO back then – but really in the saloon cars it was funny because depending on the package they had on the car or whatever, they might help cool the brakes, they might help aero wise, they might not do anything, they might even be a negative!

“And so whoever was leading or winning in the series, we had all these little games being played by their competitors and people would be trying to copy them. They’d say, ‘It had to be the fans!’ So they’d put fans on the car too. We had crew chiefs talking our ears off trying to find out how the fans would help their individual cars, but because all of the chassis were different and had different aero concepts, we had no answers for them. It was all just head games. But it was all part of the fun of the series.”

Wheel fans made their way into other series – notably on the fearsome Audi Quattro Trans-Am cars. Donnelly smiled when recounting the extremes Audi went to in crafting their own fans. “Audi spent more money developing the cooling cones than they did buying wheels! BBS didn’t develop those cooling cones. That was developed in the wind tunnel – actually through some universities – with Audi and they were basically trying to evacuate any air underneath the car. It wasn’t about cooling brakes; it was about getting everything out from beneath the car. For a lot of the other guys, though, you couldn’t always have a logical conversation with someone about the actual benefits. They were going to do what they were going to do and they believed they were going to get the benefit out of it, one way or another.”

BBS used aluminum to make wheels for many years, eventually developing a one-piece wheel that became popular in the GTP series, but when Nissan came asking for the same wheel to be made from a lighter alloy, BBS obliged, even if the costs seemed astronomic at the time.

“They went to the one-piece wheels only because of weight,” said Donnelly. “And then Nissan bought the one-piece magnesium wheels they were commissioned from us. For us, we were like, ‘That’s a lot of money!’ But at the same time, if they were spending to save three pounds of unsprung weight, it was worth it to them And how much money would you have to have stacked up to buy the engineering and build the components to take that weight off elsewhere? It was a no-brainer for them.”

“Back then I think a three-piece on that car was somewhere around $1300, something like that. And that would have been with all the best components that we could muster up at that point. For the magnesium one-piece, add about another 50% added on and that was the price and we were kind of almost like shell-shocked and embarrassed to try to quote that price. And then the reality, I guess, when you look back on it they were burning so much money it didn’t matter. That was actually pretty cheap.”

ALMS: 1998 Petit Le Mans Program

Take a gander inside the program for the what’s recognized as the first (unofficial) race for the American Le Mans race, the inaugural Petit Le Mans event held at Road Atlanta in 1998. While the 1999 12 Hours of Sebring owns the distinction of being the first official ALMS event, the ‘Little Le Mans’ from the previous year set into motion the series we know today.

The newly renovated Braselton, Ga. track played host to the first event that married the cars and rules conforming to ACO regulations to the vision of Don Panoz for an American-based series for Le Mans-spec cars to have a home.

Run just five years after the close of the GTP era, the first ALMS race could be considered a bridge between IMSA’s past and future. Petit 1998 featured GTP’s replacement, World Sports Car (WSC), and the Le Mans Prototype (LMP1), and before long, WSC gave way to the LMP cars of today.

And as you’ll see inside, more than a decade later, many of the same faces are present for the 2009 edition of Petit Le Mans.

(Courtesy of the American Le Mans Series)

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GTP: 1977 McLaren BMW Camel GT Press Kit

Press kit for the 1977 McLaren BMW 320i Camel GT team and driver David Hobbs. Powered by a 2.0L four cylinder engine, the flame-spitting Citicorp-sponsored 320i took four wins during the 1977 Camel GT championship.

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GTP: 1981 Kenwood BMW Press Kit

Press kit for the 1981 March BMW M1/C IMSA GTP team and driver David Hobbs. Powered by a 3.5L inline-6, the March was one of the earliest GTP-class designs.

(To see the full-sized images in each gallery, click the icon at the bottom right on the menu bar.)

GTP: 1986 Daytona Finale IMSA GTP Race pt1

The final win for Bob Tullius in the GTP series also marks the first win for Chip Robinson in part 1 of the 1986 Daytona finale.

Courtesy of the American Le Mans Series.

GTP: 1986 Daytona Finale IMSA GTP Race Broadcast pt1 from GrandTouringPrototype.com on Vimeo.

GTP: 1986 Daytona Finale IMSA GTP Race pt2

The final win for Bob Tullius in the GTP series also marks the first win for Chip Robinson in part 2 of the 1986 Daytona finale.

Courtesy of the American Le Mans Series.

GTP: 1986 Daytona Finale IMSA GTP Race Broadcast pt2 from GrandTouringPrototype.com on Vimeo.