Triumph TR250K: The American concept that might have saved the British Auto Industry

Story by Peter Brock • Photography as Credited

Back in the golden era of SCCA “amateur” racing, before the rise and demise of the club’s money-laden Can-Am and Trans-Am series, there was little professional road racing in America. In spite of the fact that club events were supposed to be about sport and not money, there was in fact some real factory-backed competition among those few manufacturers who profited from the realization that success on the race track was an important marketing tool for the sale of their cars. 

Production-class race cars were just that, with the emphasis on “production,” so the fans could believe that what they were watching on the track was very close to what was sold on the showroom floor. Little visual modification was permitted to the production bodies, but almost anything was legal under the hood, provided it was modified using the car’s actual production components with no metal added. 

The big money in those days was in C-Production, that crucible of performance where the faster sports cars from the industry’s biggest names fought it out to the limit of the rules. Leyland-Triumph, Porsche, Datsun and even Toyota were the main participants. 

With the obvious advantage favoring those teams with the fastest, best-engineered cars, the directors of motorsports for each marque involved were all wisely looking far ahead to make sure they’d have the raw equipment to succeed whenever the opposition upped the ante with the introduction of a new model. 

Perhaps the most visionary leader of that early tumultuous period was Triumph’s R.W.“Kas” Kastner. His carefully developed Triumphs had dominated the SCCA’s Production classes for years, but by the late ’60s he could see that manufacturers in Japan and Germany were improving their offerings at a faster rate than his slower-moving, conservative English masters. He decided he wasn’t going to get left behind.

Because of the sheer size of the United States, the SCCA had wisely divided the country into regions, making it more practical for privateers who didn’t have the budgets to travel long distances to earn points for their regional class championships. The goal for all these top amateurs was, of course, to win one of the SCCA’s national championships.

Photography Credits: Peter Brock

The Gamble

This is where manufacturer support became crucial. To increase their chances of qualifying for, and then winning the SCCA’s coveted National Championship Runoffs held at the end of every season, each of these manufacturers— with the exception of Toyota, which had only a single two-car team with Shelby—quietly backed a couple of favored multicar programs. In addition to being responsible for representing the factories on track, each of these fully funded racing programs was also responsible for developing the tuning expertise to modify their cars and also make available those rules-approved, limited-production racing components that could be sold to privateers.

Triumph sponsored two teams, using tuning guru Kastner on the West Coast while Bob Tullius’s Group 44 Inc. reigned supreme on the East Coast. Datsun’s forces were similarly aligned with Brock Racing Enterprises in California and Bob Sharp Racing in Connecticut. 

Porsche, always serious about winning the Runoffs, fielded three teams. Al Holbert’s team covered the East Coast with Alan Johnson’s San Diego-based squad on the West Coast. Owner/driver Bob Hindson ran his similar two-car effort out of Kansas City. 

With the top three regional points-winning cars in each class from each region qualified for the Nationals, the C-Production grid at the season finale was about as close to real professional racing as anything in the day. Since each of these powerful teams could be expected to qualify both of their cars in each of their respective regions, it didn’t leave much room near the front of the Runoffs grid for the true privateers. 

With four Triumphs, four Datsuns, six Porsches—each with one of the best “amateur” drivers in the country at the wheel—the C-Production shootout at Road Atlanta was some of the best racing ever seen in America. It wasn’t unusual to have the first six or eight cars all within a second in final qualifying. These manufacturers were spending more money at that time in C-Production than nearly any other type of racing in America; it was indeed the SCCA’s golden era. 

Triumph’s Kastner realized that if his super-conservative management in England didn’t soon come up with something new and better to fight off his increasingly quicker German and Japanese competition, he’d soon be shut out of the running. Worse yet, Triumph sales would probably fall off so badly that the English firm could go broke.

Kastner’s carefully developed modifications to Triumph’s aging TR-series chassis had an excellent record in competition. The Triumphs were still very competitive on most of America’s shorter circuits, but at places like Road Atlanta, Riverside and Road America, low frontal area and good aero were becoming increasingly important. The ever-improving Japanese and German imports were getting faster, while the TRs were hitting the aerodynamic wall of resistance. 

The Anti-Triumph

On his numerous trips to New York and England, Kastner had met with Leyland-Triumph’s management, trying to educate them as to what would be needed in the coming years to maintain superiority. The American office, being close to the front lines, understood completely and backed Kastner’s ideas, but the company’s long-range financial decisions were made in the U.K. The home office was reluctant to listen. 

There was little support for Kastner and his ideas. Perhaps it was the financial stress of poor sales in the U.K., or maybe they simply didn’t want an American racer meddling in their future plans. Whatever the reasons, the British execs seemed either clueless or focused on far greater internal problems to solve their dilemma. 

Over time, Kastner realized that the only way to resolve his immediate problem in America was to take matters into his own hands and build a racing concept that would demonstrate what could be done to modernize the aging TRs for relatively little investment.     

The British office patiently explained to Kastner that they were looking several years ahead to a “totally all-new” Triumph to solve his problem, but he countered by saying that their plan wasn’t going to solve his (and Triumph’s) pressing sales problem in America, and their long-range approach would cost far more than his in-hand solution. He reiterated that Triumph needed a potential sales winner now—a new production model with modern styling that would appeal to the American market, Leyland-Triumph’s biggest. This new car would also, most importantly, put Triumph back on top in SCCA racing.

Since Kastner and I had fielded rival factory-backed teams for several years, we knew that the best long-term solution for both of us would be to have equal cars. If Triumph stayed with their square-rigged cars much longer, Kastner was pretty certain his company would go broke. He was convinced that a new, aero-efficient shape mounted on a slighly upgraded TR chassis was both the answer to Triumph’s sagging sales figures in the U.S. and his problems on the race track. What made his new body-only solution so logical was that it would go into production much more quickly (and cost Leyland-Triumph far less). The other plan required designing, engineering and building a whole new car with essentially unproven components.

The “K-Car” Solution

Kastner and I came up with a plan to build a prototype that would be both a show car and a fast production race car—something easily capable of matching the best from Japan and Germany in sales and on the race track. My initial concept was a radically shaped coupe that would take advantage of the aero sleekness of an enclosed form.

Photograph Courtesy BRE Archives

It was similar in concept to the Daytona Coupe that I had recently designed for Carroll Shelby’s aero-resistant Cobra roadster. That body change alone had resulted in a 30-mph increase in top speed for the Cobra and a 25-percent savings in fuel at racing speeds. Looking at my drawings and clay model, Kastner was certain that we had a winner. The TR250’s independent-rear-suspension would be mated to Triumph’s new 2.5-liter six-cylinder to form the foundation of the new car.

With some of my sketches for the new “K-car” in hand—the name obviously a take on Kastner’s name—plus a quickly typed formal proposal outlining the bold plan to race this concept-production car at Sebring in 1968 against the all-dominant 911 Porsches, Kastner headed for England to sell his idea to Leyland-Triumph’s top management. 

With the K-car being a one-off special, Kastner knew it couldn’t technically qualify at Sebring as a real production car. Several hundred would have to be built for it to be homologated by the FIA as a genuine production model—but the concept was envisioned as a real production car, with all the road-going accoutrements required of a series-produced model. 

Even though our new K-car would be required to race as a prototype because of the FIA regulations, Kastner was certain that if it could win against the production Porsches, the American public’s reaction to the modern shape and expected performance at Sebring would go a long way toward finally selling the concept to management in the U.K. It was a daring plan, but without some drastic change, Kastner felt that Triumph was doomed. 

Disappointingly, the U.K. office was reluctant to get behind the project. On his return through New York, Kastner again stopped by Triumph’s U.S. office and fortuitously was able to squeeze a promise of some meager funds from management. They backed his plan, believing it to be Triumph’s only hope of survival. Had they not supported the idea, the car never would have been built.

The Compromise

When he arrived back in Los Angeles, Kastner took a bare, bone-stock TR250 chassis from Triumph’s L.A. warehouse and delivered it to my BRE shop in El Segundo. By then, we both realized some serious changes would be required if we were going to complete our dream in time for Sebring. Delays in getting the startup funds from the U.S. office, plus the ever-dwindling timeline, caused the two of us to rethink our strategy. 

To save both time and money, we decided to reconfigure the K-car as a roadster. The disadvantage would be in reduced aero efficiency. Some top speed and fuel efficiency, but a lighter, less complex roadster would be faster and simpler, and thus less expensive to construct. In the end, the lighter weight, resulting in increased corner exit speed, would hopefully counteract any loss in top speed. 

I spent some long hours cutting down my clay model of the coupe to size while trying to make the new shape as elegant and aero-efficient as possible. It seemed logical to raise the height of the rear deck as much as possible so that air flowing over the windscreen wouldn’t separate and create turbulent drag. 

To further offset that possibility, an adjustable spoiler was designed into the rear deck. It would force the flow of air higher and also create some downforce for improved traction at higher speeds. At the time, the raised rear deck made the car look heavier than other production roadsters of the era, but almost every open car today uses the same aerodynamic principle. 

Another aesthetic, practical and financial problem in completing our prototype in time for Sebring was the windscreen. A tall, rather flat, conventional-style windscreen from an existing production car—almost mandatory to prove our point—would keep the cost down but make our new roadster’s frontal area larger than desired. We had to keep the height to make the concept credible, however. The roadster wasn’t exactly what either of us wanted, but it still seemed a viable, aero-efficient solution. And, most importantly, it could be built in time—just barely. 

Photograph Courtesy BRE Archives

Using my experience from building the World Championship-winning Daytona Cobra, the Triumph redo went beyond the outer skin. First, we moved the six-cylinder engine rearward by 9.5 inches. That went a long way toward putting more weight on the rear wheels to improve traction. 

I then designed a lightweight, tubular space frame that we would weld to the existing chassis. This subframe would support the cowl, doors, instrument panel and windscreen frame. The main advantage of the space frame was that it torsionally stiffened the stock chassis, which then provided a better foundation for Kastner’s proven suspension components.

Once the quarter-scale clay model was completed, scale cross-sectional drawings were made approximately every 12 to 16 inches along the entire length of the model. These “station points” were transferred onto separate vellum sheets and then enlarged to full scale by simply using an old classroom projector. 

By enlarging these scale cross sections and then manually transferring those lines onto large sheets of butcher paper that were stapled to sheets of 3/8-inch plywood, the patterns for each station could be cut out with a jigsaw. These cross sections then could be sawed in half down their centerlines, then attached to either side of the main centerline template. 

Photograph Courtesy BRE Archives

When completed, this wooden “buck” resembled something like a large ice-cube tray, except that it now clearly defined the new body lines. Areas representing the wheel wells were cut out, and longitudinal stringers were added to clarify the K-car’s shape. 

Don Borth and Red Rose, a couple friends who I’d worked with at Shelby’s, now had their own shop in nearby Torrance. They were two of the best body fabricators in the nation, so I brought them in for the next step. Borth and Rose used their giant Yoder power hammer to form the car’s numerous alloy panels, fitting and then clamping them carefully over the wooden buck. Their ancient Yoder hammer originally had been purchased as war surplus at the end of World War II, when it and dozens like it had been used to help form the skins for thousands of aircraft in Southern California’s teeming aircraft industry.

While the body was being built in Torrance, the actual chassis was being finished in El Segundo at BRE. My ace fabricator, George Boskoff, was responsible for welding up the tubular subframe and attaching it to the chassis. He also carefully handcrafted the car’s beautiful headers and exhaust, plus the three-Weber, dual-choke intake manifold and, of course, the complex windscreen support from sheet steel. 

Once the built-up chassis was completed, Kastner installed a dummy engine and transmission to fit the manifolds and plumbing. He then added his own special suspension components: higher-rated springs, Koni shocks and stiffer anti-roll bars—parts based on experience gained during previous seasons with the TR chassis. 

The actual race engine was carefully assembled from mostly production components and dynoed in Kastner’s shop. With only 111 horsepower in stock form, the K-car’s new engine would need lots more power to do battle with the works-built 911 Porsches. 

Kastner had considered using a six-port Lucas fuel-injection system from the latest European-market TR6 but, thought it wiser to go with the three proven Webers fitted on the BRE manifold. The cylinder head was also ported, polished and relieved to use slightly larger valves. In addition to a 0.030-inch overbore, the compression was raised to 11.6:1 thanks to Kastner’s own pistons. Kastner also spec’ed his own camshaft and special matching valve gear. Output was increased by 91 horsepower, nearly doubling the stock figure. 

Everything behind the block remained standard, but a 3.7:1 ring and pinion was installed  to improve acceleration. With the Triumph’s stock, electrically engaged overdrive transmission essentially providing eight forward speeds, a top speed of nearly 160 mph easily was possible. Kastner replaced the stock Triumph brakes with lighter, more powerful Airheart discs.

Once the chassis was completed at BRE, the alloy body panels could then be hung on it by Borth and Rose. Unlike a real production car, both the front and rear sections were designed as easily removable components for fast servicing. Half-inch-diameter Pip Pins were used front and rear as quick-release pivots. Even the doors were attached in the same manner but with smaller pins, so the entire body could be stripped in minutes. 

The new structural rocker panels each carried a 14-gallon fuel cell. This improved the car’s already low center of gravity without shifting any weight as the tanks emptied.

We didn’t have the time or funds to make our own wheels, but I knew of some leftover, 6.5-inch-wide magnesium Halibrands that had been made for one of Jim Hall’s Chaparral MK1s. These were purchased for a reasonable price and remachined to fit the Triumph hubs. Firestone rubber—then a big name in racing—was fitted all around. 

The cost of a real glass windscreen, always an expensive item for any prototype was solved by using a spare one built from an earlier project I had done for a Japanese company. I had several made and pulled one from storage; Boskoff then formed the K-car’s lovely windscreen surround.

Since the TR250K was officially entered at Sebring as a Group 6 FIA Prototype, it could have run legally with a simple cut-down plastic racing screen just in front of the driver, which would have been much lighter and reduced the car’s frontal area. However, since the point of this whole exercise was to demonstrate the K-car as a “production” vehicle, we wanted that full-size piece of glass and convertible top as required by the rules.

Photograph Courtesy BRE Archives

The Race

Kastner chose America’s top two Triumph racers of the period, Jim Dittemore and Bob Tullius, to drive at Sebring. Their speed in the new car during practice and the race was impressive. There had been zero time for testing and development, but it didn’t matter; the car was instantly and comfortably on pace with the Porsches. The whole effort had been done on a shoestring, but that’s all Kastner had to work with.

During the race, Dittemore easily outdistanced the Porsches that led for the first 3 hours. That comfortable lead vanished in an instant when one of the remachined mag wheels failed, taking the brake caliper with it. With no spares available, there was no choice but to withdraw. 

The End

The failure had nothing to do with the design of the car or its preparation. Had the wheel not failed, the Triumph easily could have won. However, despite the good response from the American automotive media, our Triumph prototype still failed to generate any noticeable response from the home office in England. 

That indifference was possibly on purpose, as officially recognizing the TR250K’s design could have created a liability for Standard-Triumph. Their “all-new” TR7, when it finally appeared in the fall of 1974, was most definitely influenced by Kastner’s K-car. Publicly admitting the copy, even if it was badly done, could have left them open for a claim of violating intellectual property rights.

British Leyland’s main mistake was going to the all-new chassis for the TR7; the track-to-wheelbase proportions simply didn’t match the elegance or the performance of the original. The bungled design and its late appearance might well have been one of the reasons for British Leyland’s 1975 announcement that they were bankrupt, a sad point for the giant that had once produced 40 percent of England’s cars. The skid would continue with the Triumph nameplate basically disappearing a few short years later.

From left to right: Peter Brock, Jim Coan, Kas Kastner, Jim Dittermore, Bob Avery, Ed Freudenberg. Photogragh Courtesy BRE Archives

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