THE SABRE SPORTSTAR
SABRE ENGINEERING IS A JOINT VENTURE BETWEEN WATKINS RACING AND USA RACE CARS
In April of 2000, Sabre conceived the idea for a road car that would compete in endurance racing against the best sports cars in the world, including the American icons Dodge Viper and Chevrolet Corvette. It would be a very low production car that would utilize a proprietary V8 motor, transaxle, composite aluminum honeycomb chassis and feature a unique retro style 'California hot rod' body design.
Sabre has gone on to assemble a multi-million dollar effort to campaign the car in Grand Am's GTS ( Grand Touring Super ) class. The car, to be known as the SportStar, is entirely its own design. It includes a proprietary chassis, a motor of unique two-valve pushrod technology, a technically advanced transaxle and corporate partners to help execute the project.
The decision to enter the Grand Am Series first is part of Sabre's a graduated plan to see the car eventually approved to compete in all endurance racing's various series and races, including the 24 Hours of Le Mans.
Grand Am Approval
After Sabre's decision to build a sports car racer based on its endurance prototype, it entered into discussions with the Grand American Road Racing Association to gain approval for the SportStar to compete in the GTO Class. After further negotiations, Grand Am approved the concept of a small manufacturer racing first to build a brand and then building road cars. In June of 2000, Grand Am sent a letter of conceptual approval of the SportStar.
In 1993, Roman Slobodynskyj penned a 3.4 liter twin turbo V8 motor for Brayton Engineering for the purpose of exploiting the push-rod two valve rules in order to win the Indy 500. Tooling was built and fifteen motors were cast and machined. Brayton assembled one motor and ran a series of dyno runs, including the following:
The Brayton push-rod engine program eventually came to the attention of long-time Indy 500 entrant John Menard. He saw the motor run and within weeks reportedly purchased it for over $2 million with the intention of running it at the next 500. Unfortunately the demands of adapting a new engine into his program were too great in the time left and the engine was shelved some months prior to the race with the intent of running it the following year.
Unknown to Menard, a similar push-rod engine was being developed by Team Penske. The validity of the push-rod concept was dramatically proven as the Mercedes branded motor dominated Indy that year with Penske cars finishing in first, second and third places. For the following year, new rules for push-rod two-valve motors rendered them uncompetitive.
With no where to run, the Brayton/Menard V8 motor program was shelved and then sold at a Kruse auction held in Indianapolis. Brayton later purchased the motor program back from the auction buyer.
The engine sat until Roman, in prelude to his designing Sabre's prototype endurance racer, did a thorough reading of the rules and realized that his twin turbo push-rod V8 Indy motor if configured to run in endurance racing could be utilized in the SportStar. The rules allowed a larger air-inlet restrictor and more turbo boost for the two valve compared to other engine designs.
Sabre then entered into a purchase agreement with Brayton to buy the Slobodynskyj designed motors, and the right to acquire all tooling and patterns. The original dyno motor has been sent Ken Dutweiller and run on the dyno in March, 2001. The results were stunning and backed up the Brayton tests done earlier. On very small turbos and on 25 pounds of boost, the motor produced 961 HP and easily revved over 9,000 RPMs.
The completion of the development program includes resizing the turbos for the specific road racing application and experimenting with restrictors configurations to develop the maximum horsepower and torque.
At 25 pounds of Boost; 209 C.I., 3.4 Litres
Maximum Horsepower: 961 @ 8,800 RPMs
( 4.6 HP per Cubic Inch )
Average Horsepower: 915 Foot Pounds
Maximum Torque: 633 @ 7,300 RPMs.
Average Torque: 594 Foot Pounds
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