Project T-Rex: 1974 TVR Resto-Mod Proves Dinosaurs Still Exist


Chapter 1 – The Concept

Where does one start with any automotive project? Usually, it’s a concept, idea, or dream. In this particular case, the goal was to build a car that could compete successfully in everything it was subjected to; from autocross and road courses to speed time trials. Heck, while we’re at it, let’s toss in the five disciplines that come with the Optima Ultimate Street Car competition as a target goal–Road Rally, Design & Engineering, Autocross, Speed Stop and Hot Laps. When we finish this project, and we can honestly put a checkmark next to each one of those, we’ll have quite the competitive vehicle that will be a real force to be reckoned with.

Choosing A Winner

So what car would you use as the foundation for such a build with lofty goals? There are a few off the top of our heads that we can think of, and reflecting on a few (maybe a bit more than “a few”) past winners, a Corvette would certainly be a solid choice found in many of the USCA classes. Going down the list, the Mustang GT and Chevy Camaro frequently do rather well in the GT class, but half the fun of a project is to explore uncharted territory; to make a truly unique build that will really stand out among a sea of usual suspects.

Reflecting on what goals we actually want to achieve, an inspiration came from a chance encounter with a classified ad offering for sale a “barn find” caliber 1974 TVR 2500M that had been sitting neglected in someone’s backyard for well over 20 years. Ding, the light came on!  Done right, the dexterous TVR could likely be one of the most versatile and prolific race cars (and street machines) of its type on the planet. In fact, TVR could very well stand for “Triple Venue Racer.”

Where Did This Come From?

Since most folks aren’t familiar with TVR, a little back-story is in order. Originally founded by Trevor Wilkinson in 1947, the brand name was created by simply plucking three letters out of his first name, vowels be damned. TVR’s first brush with fame in the U.S. came in the early 1960s when the importer, Jack Griffith, took note of what Carroll Shelby was doing and decided to one-up his pal. At the time, Griffith was storing the AC cars brought in from England by Shelby at his Long Island, NY facility prior to their being shipped to Carroll’s Venice, CA shop where they were being transformed into Cobras. After some speculation and deep thinking, Griffith deduced that the svelte tube-chassied, independent front and rear suspension-equipped TVR Grantura was lighter and more nimble than the AC, and made the perfect candidate for some Ford V-8 power.

This is a 1970 TVR Tuscan LWB SE V8. It came with a 302 cid “Boss” Ford engine from the factory.

Griffith’s creation was scary-fast and more than a match for the Cobra. Accordingly, he commenced building some Anglo/American hot rods of his own, and the TVR/Griffith 200 (1963-64) and Griffith 400 (1964-67) came to be. Performance notwithstanding, the Griffiths suffered from reliability issues and never quite realized their true potential on the track. Moreover, trouble brewed and another “nail in the coffin” occurred when a massive maritime strike left unfinished TVRs on the docks for an extended period of time. With the inability to produce complete cars dooming Griffith’s engine deal with Ford, they ultimately succumbed to financial burden and forced the TVR factory into bankruptcy.

A peek at the engine compartment of the Tuscan.

Time To Give Up?

All hope was not lost, however. TVR was taken over by Martin Lilly, who responded with his own Ford V-8 powered car in the form of the Tuscan (1967-71). However, the early 1970s saw the advent of the gas crisis and TVR began producing a variety of cars (Vixen and M-series) with feeble 4 and 6-cylinder powerplants. Of course, there were performance enthusiasts who lusted for “the good old days” and the importer, TVR North America, responded in 1974 by taking the uninspired 2,498 cc Triumph engine out of some 2500M models and stuffing in a 302 cid Ford “Boss” engine, top-loader 4-speed and a Corvette IRS. They marketed this as the “5000M.” Ultimately, cars were shipped out of TVR’s Blackpool, England facility sans drivetrain to become 5000Ms.

The “M Series” was introduced in 1972 and was produced through about 1976. There were the 2500M (which is the basis of T-Rex and originally came with a 2,500 cc motor, 3000M and 1600M) plus the 5000M created by TVR North America and Ford V8 equipped.

Fast forward to 2017, where the concept of converting the long-neglected 1974 TVR 2500M  into contemporary 5000M standards is coming to fruition at Penta Motorsports in Canoga Park, California. And instead of using a Windsor-style 5.0L engine like the original, a 5.0L DOHC Coyote with a Borla 8-stack EFI will provide the motivation. To handle the increased power (271 hp for the 5.0L Windsor vs. about double that for the warmed-over Coyote) the original TVR pipe is giving way to a new chassis that features an Art Morrison Multi-Link IRS and Sport IFS up front. More on that part of the build later, however.

The whole thing started in the early 1960s when TVR dealer Jack Griffith took a cue from his pal Carroll Shelby and stuffed a 289ci small-block Ford into a TVR Grantura. The cars were marketed as either the Griffith 200 or 400. Shown here is a Griffith 200.

Number Crunching

The stock TVR 2500M crossed the scales at 1,975 pounds with its 6-cylinder Triumph engine (rated at a whopping 106 horsepower). Of course, the car’s light weight contributed to respectable performance. Now, with the added bulk of the V8, 2in by 4in main rails vs. 1-1/2in square tubing and full 10-point competition roll cage, a weight of 2,350 pounds seems like a very reasonable target. Numbers can be arbitrary, but when you compare it to the new Corvette or Mustang GT which can weigh north of 3,600 pounds or even the Camaro ZL1 (a real whopper hovering around 4,000 pounds), you can simply salivate over the weight savings the TVR offers.

Additionally, there’s one more important factor favoring the TVR; weight distribution. A Mustang GT, by way of example, has a 53/47 front-to-rear balance. The Camaro is said to be 52/48 and the ‘Vette near 50/50. As the TVR’s engine placement is a good distance aft of the front spindles, it’s likely to be very favorable. Corner-weighing this puppy when she’s done will be an interesting and revealing exercise.

When it comes to actual bragging rights prior to final completion, it’s always fun to predict a vehicle’s performance. These days —thanks to myriad online calculators— it’s relatively easy. Plugging in a wet weight of 2,600 pounds for car, fuel, and driver plus a flywheel horsepower factor of 500 (hopefully a conservative figure) the 0-60 time should be 2.89 seconds and the ¼-mile clocking predicted to be a 10.61 elapsed time and 142 mph trap speed. Using a probable 3.45:1 ring and pinion gear, .062 overdrive final trans gear and 25.5in tall tires the TVR would be going 209 mph at 6,000 rpm. Now, if the actual performance comes even close to these computerized simulations there’s a helluva ride in offering to occupants.

What’s In A Name?

Finally, in coming up with a name for this project we’ve taken “TVR” and added “EX” for its experimental status, and the sake of graphics added a small “8” in the “V” as a nod to the engine configuration (something Henry Ford came up with in 1932). The resulting TVREX can be shortened to “T-Rex” and salute the most ferocious beast to ever roam the planet.

We did a computer-generated illustration of the finished car. Not everything is exactly how it will be when complete (wheels, tires, brakes, etc.). We’ll modify the body to match TVR’s factory “Widebody” models, which include a flare over the front wheels and widened rear fenders. It’s shown with and without graphics similar to what’s need for the USCA’s Optima series.

This brings us to the new 2018 Griffith, which boasts a 5.0L DOHC Ford Coyote that’s been enhanced by Cosworth. This will lead to an interesting comparison, as T-Rex should have similar power, weigh less, and have a multi-link IRS rather than a twin-wishbone setup.

The rear view shows use of LED taillight assemblies from J.W. Speaker, replacing the original ones (which TVR got from the Ford Cortina) and a pair of Borla Boomer mufflers (there’s really no room inside the confines of the body to mount conventional units). Diffusers will be employed for stability, and a “Gurney Flap” added if more rear downforce is needed. Stay tuned as we follow this project through to completion, chronicling the various steps along the way. We hope you’ll find this an interesting, informative journey.

About the author

Bill Holland

Bill Holland has been involved in racing and the performance aftermarket since the 1960s in the capacities of racer, speed shop proprietor, journalist, street rodder, designer and advertising/PR/marketing professional. Along the way he’s raced Top Fuel and Funny Car, been editor of NHRA’s publication, National Dragster, was involved in off-roading as publisher of SCORE News, built a variety of Featured Vehicles for the SEMA Show, as well as a Track “T” that was a Contender for the AMBR award. He currently races vintage sports cars. Bill was inducted into NHRA’s California Hot Rod Reunion Hall of Fame in 2017.
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