In the world of time attack in Japan, one of the most venerable tracks and benchmarked venues is Tsukuba Circuit. This famous racetrack could arguably be the birthplace of time attack competition. Although Tsukuba opened in the late 1960s, tuning shops didn’t start to actively compete in time attack-style venues until the Rev Speed Tsukuba Super Battles of the early 1990s. The Super Battles pitted together shop project cars and high-profile customer vehicles in competition for the quickest lap. At the first event, Tarzan Yamada piloted the Mine’s R32 GT-R to victory with a lap time of 1:00.85. While there have been plenty of sub-one minute lap times since then, this inaugural lap time has made the minute a benchmark target for all competitors.
Text by Richard Fong // Photos by Dino Dalle Carbonare
GReddy Performance Products and its parent company in Japan, TRUST Co., Ltd., have been closely monitoring the pulse of the industry. They were quick to work with high-profile partners like Ben Sopra and 6666 Customs/TRA Kyoto on projects involving the R35 GT-R and the Toyota 86. These platforms have led the import performance market since the global recession began its recovery. Even two years after its initial release, the Toyota 86/Scion FRS/ Subaru BRZ continues to be the go-to platform for enthusiasts and the aftermarket. According to Toru Kawashima of TRUST Co. “We brought over a USDM Scion FR-S initially to serve as a test bed and prototyping platform to develop products for the left-hand-drive markets like the USA. Once we were satisfied with the parts development program, we decided to pull out all the stops and unlock the potential of the FR-S by developing it for time attack competition.” TRUST Co. set out to build the FR-S to break the one-minute barrier at Tsukuba. Since stock 86s and BRZs have recorded times around one minute and 10 seconds, achieving this goal would require a balanced combination of power, suspension and aerodynamics.
GOING FURTHER WITH THE FA20
Producing the power needed to reach their goal would require a significant increase over the 200 ponies that the stock engine makes at the crank. With this in mind, forced induction offered the best solution. However, reinforcing the bottom end was a must to ensure reliability under boost. The Toyota 4UGSE boxer engine, essentially a Subaru FA20, is still a fairly new mill with limited aftermarket development. This left the TRUST Racing Team with few choices. After breaking down the engine, the cylinders were filled with a set of prototype 9.0-to-1 GReddy pistons that join the stock crank by way of Carrillo connecting rods. At each end of the shortblock, the cylinder heads received some light port work before being reunited with the block. A pair of prototype head gaskets ensures a proper seal between the heads and the block halves. According to TRUST/GReddy, aftermarket FA20 camshaft blanks have yet to reach production; therefore, no aftermarket cam options were available for the build. Thus, the factory bumpsticks continued to actuate the valvetrain.