GTP: 2010 Rolex Monterey Motorsports Reunion Gallery

August 19, 2010 by · Leave a Comment 

Enjoy a collection of 166 photos from the 2010 Rolex Monterey Motorsports Reunion, featuring the IMSA GTP class.

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

GTP: Rolex 24 Retrospective

January 27, 2010 by · 2 Comments 

Enjoy a collection of Rolex 24 photos from our archives, with images ranging from 1985 to 1993.

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

GTP: Wheels Of Fortune

September 23, 2009 by · 1 Comment 

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.”

BBS' John Slagle. (©

BBS' John Slagle. (©

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.”

Wheel fans in the front and standard BBS Golds in the back was the popular choice for many years in the GTP series. (Courtesy of Porsche)

Wheel fans in the front and standard BBS Golds in the back was the popular choice for many years in the GTP series. (Courtesy of Porsche)

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…”

Andy Wallace stands in the paddock at Le Mans in 1991 in front of TWR Jaguar's BBS wheels. (Courtesy of LAT)

Andy Wallace stands in the paddock at Le Mans in 1991 in front of TWR Jaguar's BBS wheels. (Courtesy of LAT)

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.

Wheel fans pre-dated the GTP era...and weren't always a positive influence on performance. (©

Wheel fans pre-dated the GTP era...and weren't always a positive influence on performance. (©

“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.”

Vanes of a wheel fan. (©

Vanes of a wheel fan. (©

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.”

Nissan paid handsomely for BBS's lightest wheels for their 1992 and 1993 GTP cars. The ill-fated P35 from '93 is pictured here. (Courtesy of Nissan)

Nissan paid handsomely for BBS's lightest wheels for their 1992 and 1993 GTP cars. The ill-fated P35 from '93 is pictured here. (Courtesy of Nissan)

GTP: 1986 Daytona Finale IMSA GTP Race pt2

September 1, 2009 by · 2 Comments 

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 on Vimeo.

GTP: Hotchkis At The Historics

August 24, 2009 by Mark Hotchkis · 1 Comment 

Evolving from the all-conquering 956, the Porsche 962 made its debut at the 1984 Daytona 24 Hours and immediately showed incredible potential. Hotchkis Racing purchased the Porsche-commissioned Fabcar tub #962F01 from Holbert Racing in the summer of 1986, and has owned it ever since. As a kid, I remember staring through the same chain-link fence (which separated pit lane from the paddock area at almost every race track), watching my father John, co-driver Jim Adams and various other drivers — Chris Chord, Rob Dyson, Bob Kirby and my older brother John — all pilot the flame-belching purple Wynn’s car.

From the tight confines of the streets of Miami to the high banks at Daytona, the Hotchkis Racing 962 served as a dependable warhorse and never disappointed.

Today, the car lives in a deep, dark storage in Southern California, rarely seeing the light of day except for those one-time special events like the Rennsport Reunion and of course, the Rolex Monterey Historics. When we received our acceptance for the 962 at this year’s event, it was time to awaken the beast, dust her off and shake her down at a local track. All systems were go and considering the brief on-track time during the Historic weekend, we decided new tires would be a unnecessary, so we utilized our Goodyear rubber from the Rennsport Reunion in 2007.

Mark Hotchkis (L) poses with Gunnar Jeanette before their 10-lap race at the 2009 Historics. (©

Mark Hotchkis (L) poses with Gunnar Jeanette before their 10-lap race at the 2009 Historics. (©

Once we arrived at Mazda Raceway Laguna Seca and settled-in, it was time to head out for our first of two practice sessions. Our Porsche 962 is a 3.2ltr air-cooled single Garret turbo car, as opposed to a twin turbo water-cooled car. The engine is maintained by Porsche Motorsport North America and features the twin plug ignition of the later IMSA air-cooled 962’s, as opposed to the early single-plug, side intercooler engine. There is no mistaking an air cooled 962 engine as it warms up in the paddock. It tends to spit, shake and rumble at idle but is very crisp at the same time. For all of roughness while warming up, it clears up once it’s revved and the whine of the powerful horizontal fan takes over — almost like a supercharger sound.

Call me demented, but I could listen to the engine struggle at idle all day long – it’s too cool!

What is it like to drive a Porsche 962 at speed during the Historics? Although my time behind the wheel of this car is quite limited, it is without a doubt one of the most comfortable and confidence-inspiring race cars ever manufactured. As I slip down into the cockpit, I immediately recognize the well-planned ergonomics, all controls at my finger tips and a seat that anyone could easily fall asleep in.

Operating the 962 is quite simple: strap in, adjust the mirrors, take a deep breath then turn the key to start the engine. That’s right, the 962 utilizes a keyed ignition right out of a 911! Once the engine has lit, cockpit noise is dominated by the whirl of the horizontal fan. Select first gear — over to the left — pull back, and we’re off. The 962 uses a five speed synchro transmission with second through fifth gears set on a standard H-pattern. Accelerating up to speed, the engine’s fan gets drowned-out by the building turbo pressure and raw grunt of the Porsche flat-six.

Boost builds progressively and not at all like an on/off switch which one may think would be the case if they simply looked at the size of the turbo. Under hard acceleration, at 70 inches of mercury, it sounds as though an early-style jet engine is chasing from behind, but as the throttle is cracked for the next braking point, the twin wastegates make an instant loud chirp through the exhaust primary.

Our ten lap race for this year’s Historic was far too short. It should really be fifty minutes to an hour, or at least a fuel tank’s worth of running! We started on pole with Gunnar Jeannette alongside in the Kremer K8. Approaching the flag stand on the front straight it’s typical to hold the brake pedal with your left foot and build some boost with the right foot. At the green flag we both accelerated pretty well but I probably should have made it a second gear start instead of spinning the rears in first gear, but it all worked out entering Turn 2. Gunnar applied the pressure into the brake zones and through the turn-in points as I struggled for front grip.

The purple beast lines up alongside the Kremer K8 as the grid prepares to roll. (©

The purple beast lines up alongside the Kremer K8 as the grid prepares to roll. (©

The Hotchkis 962 utilizes a spool instead of a limited-slip differential and I still have not adjusted to it. This setup requires an aggressive corner entry with some rear brake bias to help rotate the car, and then to catch it with the throttle, otherwise the front end simply understeers too badly. For the first two or three laps Gunnar was right there, carrying monster corner speed while I was able to gap him in a straight line. As the pressures and temperatures began to build, the car came alive and I could get into a rhythm and concentrate on not making any mistakes and enjoying the brief time I had with such an incredible race car.

Aerodynamically and mechanically our car had good balance. The tunnels under the 962 really help with downforce and as speed builds the suction builds, and that is felt immediately through the steering wheel; it takes added effort to make even the slightest input. Braking during the race was pretty good. I don’t know if it was our old tires or the slick track or both but I would lock both the front and the rear separately at different brake points during the race. For example, I locked the inside front entering turn 2 and at the top of the corkscrew and locked the rears entering turn 11. Otherwise, the big Brembos hauled the car down at a good clip.

For the last four laps of the race I felt strong and mistake-free. Our car encountered traffic and simply sliced its way through, never skipping a beat and it gave me a chance to take it all in — the amazing engine sounds from behind me, the remarkable grip and ease of placement the 962 allows. Compared to other prototypes of the ‘80’s, the 962 is so comfortable and feels softly sprung without a lot of roll resistance so the knife-edge grip loss (common with other GTP cars) simply does not exist.

That’s probably the main reason why many drivers can step into this car and build confidence quickly – it’s that friendly. We went on to win the ten lap super-sprint and it all seemed to end almost as quickly as it began.

It was another race in the books for the Hotchkis 962 and I hate to say it, but now she’ll head back to the dark, dungeon-like storage facility. The purple beast will stay there until it’s time to be awakened again for another special Porsche event in the future.

GTP: Hotchkis Porsche 962 In-Car, Mazda Raceway Laguna Seca from on Vimeo.

GTP: 1989 Portland IMSA GTP Race Broadcast

August 21, 2009 by Marshall Pruett · 1 Comment 

Spend 97 minutes with Geoff Brabham, Price Cobb, Davy Jones and the rest of the players in the 1989 Portland IMSA GTP race…one that went down in great controversy after the checkered flag was displayed early.

Jaguar’s Price Cobb crossed the finish line first as the checkered flag waved prematurely, and Geoff Brabham crossed it last just when it was scheduled to fall. Despite Nissan’s victory circle celebrations, the win would be overturned and given to Cobb.

While it made for great drama at the time; it’s all IMSA fans spoke about, but the altered outcome did little to sway the championship as the Nissan/Brabham freight train carried onto their second consecutive GTP title.

1st Lammers / Cobb Jaguar XJR-10 Castrol Jaguar Racing
2nd Geoff Brabham Nissan GTP ZX-T Electramotive Engineering
3rd Chip Robinson Nissan GTP ZX-T Electramotive Engineering
4th Nielsen / Jones Jaguar XJR-9 Castrol Jaguar Racing
5th Miller / Earl Spice SE89P Chevrolet Jim Miller Racing
6th Andretti / Wollek Porsche 962 Busby Racing
7th Moran / Ribbs Eagle HF89 Toyota All American Racers
8th Mass Porsche 962C Bayside Racing/Bruce Leven
9th Adams Porsche 962 Hotchkis Racing
10th Gianpiero Moretti Porsche 962C Momo/Gebhardt Racing

GTP: 1989 Portland IMSA GTP Race Broadcast from on Vimeo.

GTP: 2009 Monterey Historics Trackside Action

August 19, 2009 by · 8 Comments 

Here’s 36 shots from trackside at the 2009 Monterey Historics, featuring the IMSA GTP cars.

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

GTP: Sounds Of Laguna Seca IMSA GTP, 1987

August 14, 2009 by · Leave a Comment 

What happens when a 16-year-old Marshall Pruett drives down to Laguna Seca to watch the 1987 IMSA GTP race with a camera in one hand and a tape recorder in the other?

First, he takes a bunch of photos that range from blurry to overexposed. Second, he fashions a hook out of a coat hanger to suspend his tape recorder from the fence on the outside of turn 2, then captures some of the most delightful sounding racing cars he’s ever heard.

More than twenty years later, and with that cassette tape somehow managing to remain intact, I transferred the audio to my laptop, cleaned it up as best I could, and posted it below.

The warbling sound at the beginning of the tape is accurate — it’s a driver pumping the brakes to warm them up, hence the engine note rising and falling. From there, the first big HOLY %$!* burst of sound (at 00:41) is a Group 44 Jaguar XJR-7 streaking by at full chat.

I don’t know all of the physics and mechanics behind it, but the Group 44 V-12 engines had a completely different sound than the TWR V-12s. The XJR-9s and 12s had more bass — they had equal parts Motown Soul and Memphis funk coming from their exhausts.

Group 44’s had more treble and lived at a higher register — they were operatic in the tinny heights they reached. I still grin today whenever I hear this tape.

Take a listen and experience the Jags, Porsche 962, Buick and Chevy turbos, a Ford V-8, and variety of Pontiac and Mazda-powered Lights cars as they sounded back in 1987.

GTP: 1987 Sounds of Laguna Seca from on Vimeo.

GTP: Dyson Racing Retrospective Photo Gallery

March 13, 2009 by · Leave a Comment 

Enjoy an in-depth pictorial history of the Dyson Racing team’s tenure in the IMSA series.

Courtesy of Dyson Racing.

(To see the full-sized images, click the icon at the far right of the menu bar below)

GTP: 1986 Lime Rock GTP Race Broadcast pt 1

March 11, 2009 by Terrance · Leave a Comment 

GTP: 1986 Lime Rock GTP Race Broadcast pt 1 from on Vimeo.

The 1986 IMSA GTP race broadcast from Lime Rock in Connecticut.

Courtesy of the American Le Mans Series.