A Brief History of Street Stock Endurance Racing | 1985-2010

By Staff Writer
Oct 21, 2020 | Endurance Racing | Posted in Features | From the Feb. 2010 issue | Never miss an article

Photography Credit: Photosbyjuha.com

[Editor's Note: this article originally ran in the February 2010 issue of Grassroots Motorsports]

Story by Beth Dolgner

Professional street stock endurance racing has now been with us for a quarter of a century, and while many of the participants have come and gone—drivers, manufacturers and even the series organizers—the teams and fans have remained loyal to one of the truest forms of motorsports. What we have known as the Grand-Am Koni Challenge has roots that weave through North America’s professional racing scene.

The Sports Car Club of America gets the credit for planting the seeds for today’s street stock format. They first introduced Showroom Stock racing in 1972 as a cost-saving class for amateurs, setting a price cap for cars at a mere $3000. 

The next big move occurred a decade later. “Mitsubishi came to the U.S. in the fall of 1982—asked me about a way to go racing inexpensively,” recalls longtime racer Dave Wolin. “I suggested the Nelson Ledges 24 hour; that was just getting going as a showroom stock race that had attracted the attention of Detroit manufacturers and the press.”

Wolin took a Starion to Nelson and won handily thanks to two-hour stints per tank of fuel plus some good drivers, he explains. “The following year, 1984, I won again,” he adds. Dick Guldstrand and Steve Saleen won their respective classes, too. The field also included name brand drivers like Stirling Moss and Parnelli Jones plus SCCA Vice President Bill King. 

After the race, Dick, Steve, Jim Trueman, Bill King and I decided to set up a series—the U.S. Endurance Championship—with four races,” Wolin continues. Their schedule would include an already existing six-hour regional at Lime Rock, a 24-hour at Mid-Ohio—Trueman, the track owner, agreed to host the race on the spot, Wolin adds—plus a 12-hour affair at Willow Springs. “Earl’s, my sponsor at the time, agreed to pick up the tab, and we won our class at each,” Wolin continues. 

This four-race series got the SCCA’s attention, and with King’s help it became a professional affair in 1985: the Playboy United States Endurance Cup. However, they weren’t the only ones with the idea. At the same time, rival sanctioning body IMSA introduced the Firestone Firehawk Endurance Championship. 

Throughout street stock racing’s dramatic evolution—gone are the days of $3000 race cars—it has remained a popular format. While the fans seem to enjoy seeing nearly stock versions of their street cars battle for supremacy, the manufacturers long ago realized that the venue has value for both promotions and development.

Street stock racing is important from the manufacturer side because it shows how good a manufacturer’s product is right from the assembly line,” notes Bill Auberlen, who has raced production-based cars—mostly BMWs—for several years. “You put some brakes on it, roll bar, fuel cell, and you go racing. That’s how good that car is.”

As a benefit, some great racing takes place at these events. “If the fans want to watch some of the coolest racing with 50-car fields, that’s where they’ll see it,” he continues. “It’s cars separated by nothing but the paint between the two, and the racing is terrific. It’s always 10 cars battling for the lead at the end of the race.”

The format has also helped many drivers climb the motorsports ladder. Names like Stirling Moss, Derek Daly, Elliott Forbes-Robinson, Boris Said and brothers Bobby and Tommy Archer have graced entry lists. Even after they’ve reached the top of the heap, however, racers tend to stay interested in the series. Despite other gigs in other professional series, Randy Pobst has been a street stock regular since the beginning. The same goes for hotshoe and recently retired GM exec John Heinricy.

A lot of guys do well at the top of the sport and still come back to race a series like Koni Challenge,” says Terry Borcheller, whose resumé includes championships in both Speedvision Cup and Speed World Challenge. “I think I have the most fun in Koni compared to anything else I do. If you’re in a decent car then you’re in a position to win, and that’s why we do this.”

Plus, this venue is open to just about any driver, as rental rides have always been part of the format. Just write a check and join the professional ranks.

However, unlike some other motorsports series—think NASCAR or even Formula 1—the evolution of this scene hasn’t been so linear. The torch has been continually passed between groups and sanctioning bodies. Despite the haphazard gestation period, today’s professional street stock scene is quite healthy, sporting growing grids and increased manufacturer support. Here’s how we got there.

1985 | SCCA Offers Professional Showroom Stock

Photography Credit: Geoff Hewitt

The SCCA was quite involved in professional road racing by the mid-’80s, and in 1985 they launched the Playboy United States Endurance Cup, the sanctioning body’s first professional street stock series. A team points fund was sponsored by Escort Radar Warning Receivers, and 10 car manufacturers entered the series. While spec tires would eventually become a big part of the formula, in this first year teams could select rubber from eight different brands.

The Playboy Cup’s sole season consisted of only six events, but those races varied in length from four to 24 hours. Some of the country’s best tracks were visited: Road Atlanta, Sears Point, Lime Rock and Mid-Ohio. 

Was it a success? The series made its debut at Riverside Raceway, and 87 cars showed up to set a record for the most entrants in an inaugural pro race.

Drivers such as Don Knowles, Stirling Moss, Elliott Forbes-Robinson, John Heinricy and actor Bobby Carradine competed in four classes: SSGT, SSA, SSB and SSC. Machines in the mix included Corvettes, Dodge Shelby turbos, Peugeot 505 Turbos and the Honda CRX Si.

1985-'94 | IMSA Launches Competition

Photography Credit: Mark Windecker

While SCCA Pro Racing was launching their Playboy Cup, IMSA debuted their own version of professional showroom stock racing, the Firestone Firehawk Endurance Championship. As the name suggests, all teams were required to run Firehawk street tires from title sponsor Firestone.

The Firehawk series lasted for nearly a decade, and many of the same teams and drivers who are still involved with street stock racing ran in the old IMSA competition. Look through grid sheet archives and you’ll find names like Joe Nonnamaker, Randy Pobst and David Rosenblum. Three classes—Grand Sport, Sport and Touring—gave just about everything a place to race, including the BMW M3, Camaro, Corvette, Pontiac Grand-Am and even the Ford Thunderbird.

1986-'89 | Playboy Moves Out, Escort Moves In

Photography Credit: Mark Windecker

Radar detector manufacturer Escort took over title sponsorship of SCCA’s professional showroom stock series for 1986, and the name changed to the Escort Endurance Championship. That wasn’t the only news, though. The B and C classes were combined, leaving room for a new premier class called Super Sports. The popular SS class was primarily a battleground for the Chevrolet Corvette and Porsche 944 Turbo. 

Top teams included Morrison-Cook Racing, Saleen and Powell Motorsport, while notable drivers such as Bobby and Tommy Archer, Stu Hayner and Calvin Fish were often at the top of the podium.

After another six-race season in 1986, the series increased to eight events. The 1987 season was the swan song for the short-lived SS class, but it wasn’t until 1990 that the series would undergo significant changes, resulting in a new name and format.

1990-'97 | World Challenge Launches

Photography Credit: Mark Windecker

The newly dubbed SCCA Escort World Challenge Championship brought with it a whole new format, as cars were homologated by manufacturer and fit into one of two classes: World Challenge or Super Production. World Challenge cars included high-performance machines like the ever-present Corvette and the Lotus Esprit Turbo. Smaller cars that once competed in the B and C classes, like the Honda CRX, comprised the Super Production class.

Following just one season of the dual-class structure, the old Super Sports class was resurrected as Super Sport to give Ford Mustangs and Chevrolet Camaros a home. By 1992, the series was back to four classes—A, B, C and D—but races became one-hour sprints instead of long endurance events. (SCCA was out of the professional street stock endurance scene, although their World Challenge program—sponsored by Speed Channel since 2000—continues to feature production-based racers in a sprint race format.)

1995-'96 | Firestone Leaves, but IMSA Soldiers On

Photography Credit: Gordon Jolley

The Toyo Proxes RA-1 became IMSA’s spec tire starting with the 1995 season, necessitating a name change. The series became the IMSA Endurance Championship, but a lot of racers simply called the series Toyohawk.

The series still featured multiple classes for the usual suspects, including some special, limited-edition models aimed right at this market. The Ford Mustang Cobra R and BMW M3 Lightweight were both released for 1995, and they joined the legions of Firebirds, Mazda MX-6s and Honda Preludes.

1997-'98 | IMSA Sold, Bought and Renamed

Photography Credit: Gordon Jelly

Changes in ownership in the late ’90s shook up IMSA’s stability. However, street stock racing remained part of their program, even as the long-standing IMSA name was traded for Professional SportsCar Racing. With the new ownership came a new title sponsor: Speedvision. 

What was known as Firehawk just a few years earlier had become the Speedvision Cup Endurance Championship, although Toyo remained the spec tire supplier. (As mentioned earlier, Speed also eventually became the title sponsor of SCCA’s World Challenge series, confusing more than one casual fan.)

The changes didn’t go well for all involved, however. Drivers from the Grand Sport ranks started to defect to an upstart group called Motorola Cup. As a result, only six races could be found on the schedule in 1998. That was Professional SportsCar Racing’s last year for sanctioning street stock racing.

A serious rift had formed between Professional SportsCar Racing and their GT and prototype participants, many of whom were vocally angry. The sanctioning body's owners ultimately sold out to Don Panoz, who reverted the organization back to the original IMSA name. IMSA now sanctions Panoz’s American Le Mans Series.

1997-2000 | A Challenger Arrives From Canada

Photography Credit: David S. Wallens

While IMSA was going through its transformation, Canada’s Berman Motorsport Group started a rival street stock series with sponsorship from Motorola. Once IMSA got out of the street stock business after 1998, the Motorola Cup North American Street Stock Championship was the only game in town. Once again, the torch had been passed from one sanctioning body to another. 

Four classes—Grand Sport, Sports, Touring and Compact—encompassed a wide range of cars, from Miatas to Vipers. Motorola Cup also used a spec tire—first it was Dunlop, but in 1999 it switched to Hoosier.

Team Lexus was a powerhouse thanks to their army of Lexus GS 400 machines and a driver lineup that included Terry Borcheller and James Gue. Bill Fenton Motorsports campaigned a Honda Civic Si, while Speedsource ran five Porsches—911s and Boxters—with guys like Sylvain Tremblay, David Tuaty and David Haskell in the driver’s seats.

2001-'06 | The Big Handoff

Photography Credit: Photosbyjuha,com

Just days before the 2001 season officially began, Berman Motorsport Group and Grand-Am announced that Motorola Cup would become a Grand-Am event. One week later, the series ran its season opener at Daytona International Speedway—the last time it was ever referred to as Motorola Cup. After that event, the series was officially known as the Grand-Am Cup.

The most significant change to the series during the next years was the class structure. A four-class format was condensed into just two classes, Grand Sport and Sport Touring (which later became Street Tuner).

This move basically put the faster cars—the Porsche 911s, BMW M3s and even the Pontiac Trans-Ams—in the Grand Sport group, while the Honda Civics, Mazda Miatas and other smaller cars went in the Sport Touring class. Everyone ran on spec Hoosier tires. 

2007-'10 | Corporate Support

Photography Credit: Photosbyjuha.com

After six years without a title sponsor, high-performance suspension company Koni took over the naming rights. The series remained virtually unchanged aside from its new name, the Koni Challenge. Many of the teams in this current incarnation are Grand-Am Cup regulars, such as Blackforest Motorsports, Automatic Racing, Team Sahlen and Turner Motorsport. Some very familiar cars are still involved, too, including the Honda Civic, VW GTI, Mazda Miata, BMW M3 and Ford Mustang.

The Grand-Am series gets a new title sponsor for 2010, however, becoming the Grand-Am Continental Tire Sports Car Challenge. Continental, who recently announced a strategic alliance with Hoosier, will also be the sole tire supplier. And look for a new marque starting in 2010, as Kia is using the series to launch a new motorsports presence in the U.S. 

Despite some big changes over the past 25 years, street stock racing continues to attract teams, drivers and manufacturers with something to prove. 

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noddaz GRM+ Memberand UltraDork
10/21/20 6:28 p.m.

We need an update!

L5wolvesf Reader
10/21/20 9:35 p.m.

The mentioning of Dick Guldstrand and Bobby Carradine reminded me of when I was a member of the Guldstrand Racing Association (GRA) in the early to mid 80s. Being a member had a number of benefits including Dick’s knowledge and stories. At times we also got to see some of the cars he was working on including the cars he was prepping for the endurance races. I asked a lot, maybe too many, questions but Dick knew I was going to be building my IT car so he shared what he could.


At one of the GRA monthly meetings in ’85 (IIRC) he asked if any of us wanted to come up to Willow Springs for the race and possibly help and if we had a driving suit etc bring it. Myself and about 6 or so others said “HELL YES ! ! !”. The chances we could drive were pretty nil, but helping otherwise was a possibility. We ended up being fans and go-fers since the car(s) ran pretty well. I paid a lot of attention to how things were organized and run since I had aspirations of running “big time” endurance races. Given Dick’s racing history I figured he would be a very good example to follow.


One thing I recall is that it was weird. We were at a race, in the middle of nowhere, in the middle of the night and there really wasn’t much noise – Showroom Stock cars with mufflers. The front straight sounded kind of like a half empty freeway. There were brief times of not quite chaos (pit stops), but mostly hours of not much.


We GRA guys split into shifts; 3 or so in the pit area, 3 wandering around, and 3 napping. Since I’ve never really been a night person I fell asleep quick that night since it was relatively quiet (at a race) in the parking area.


We did get intro’d to the drivers as a group but didn’t interact with them much. Far as Carradine goes, I kinda wanted to say Hi since he and I were at a summer camp once about 15 or so years prior. But I wanted it to be just him and me so if he recalled the camp prank it wouldn’t be in front of a bunch of guys who might give him some BS. It didn’t happen so, oh well.

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