If you’re going in, go all in. This is the mentality and motivation behind HKS Japan’s special projects workshop builds. HKS engineers and tuners pour their experience in racing and high performance into the machines that emerge from this workshop. Anything less than record breaking is not an option.
Text by Richard Fong // Photos by Dino Dalle Carbonare
Time Attack Heritage
In 2001, HKS unleashed its carbon fiber Track Attack Altezza, otherwise known as the Tsukuba Record Breaker Version 1.0 (TRB-01). It broke the standing track record with a 55.800 second lap time. A few years later, HKS developed its carbon-fiber bodied CT9A EVO, the TRB-02.
The TRB-02 set an unprecedented lap record of 0:54.739 at Tsukuba Circuit in 2004, but was damaged in a crash shortly after. This machine was then rebuilt with the singular purpose of setting new track records. It was reborn as the CT230R, returning to Tsukuba to raise the stakes with a new record lap time of 0:53.589. But domestic dominance was not enough, as HKS then loaded up the CT230R on the slow boat pointed at America.
HKS wanted to prove its build in the heartland of American time attack at the track where records carry a lot of weight, Buttonwillow Raceway. [pullquote]HKS wanted to prove its build in the heartland of American time attack[/pullquote] In 2007, with Nobuteru “NOB” Taniguchi at the wheel, the CT230R shattered the track record with a 1:43.523 lap time, more than five seconds faster than Tarzan Yamada in the Cyber EVO and the outgoing record holder Tyler McQuarrie in the JIC Magic S15 Silvia.
Years in the Making
HKS set records that stood for a number of years, and it was time to return to the time attack stage with a new performer. Like America’s tuning community, HKS invested heavily into the development efforts of Japan’s poster child for performance, the Nissan R35 GT-R. As one of the first to offer bolt-on performance enhancing parts for the R35 with its GT570 and GT600 parts packages, HKS wasted no time moving to the forefront of R35 development.
Driven by consumer demands, HKS delivered a number of stages of GT-R packages including the GT570, GT600, GT800 and GT1000 kits. To reach a new pinnacle of performance, the special projects workshop focused on extracting more from the GT1000, leading to the GT1000+ Time Attack racecar.
Putting the Plus in GT1000+
According to HKS’ Yoshi Suzuki, GT-R development leading up to the GT1000+ spanned a total of six and a half years. Having successfully made 1,000 horsepower already, the development team had a good starting point to build upon. The VR38DETT engine’s oversquare dimensions paved the way for a 95.5mm stroker kit that retains the stock bore size which gives the VR a square bore and stroke, and a new displacement of 4,105cc. HKS connecting rods and forged aluminum pistons accompany the new crankshaft to complete the enhanced shortblock assembly.
Having greater lung capacity while attempting to breathe through a straw taking shorter breaths does little to help with aspiration. Therefore, to make best use of the increased displacement, improving volumetric efficiency was a must. HKS equipped the cylinder heads with its requisite valve spring upgrade, which complement its higher lift, longer duration 270- and 278-degree intake and exhaust camshafts. To feed the intake ports, HKS installed its High-Flow surge tanks with the Twin Injector Pro Kit. The surge tanks increase and equalize the airflow available to each of the cylinders, while the injector kit permits the installation of a second injector at each intake port, doubling the injector count to twelve.