HKS is best known for the turbocharger systems it has been developing for over three decades. But, for the last several years, there have been rumors of a line of innovative superchargers. Then came the invite to toss around a 2004 Nissan 350Z loaded with the latest offerings from this renowned Japanese tuner. The HKS Z featured the company's latest generation of coilover suspension. But, more importantly, it gave us our first encounter with the all-new GT supercharger kit.
At the heart of the kit is a highly efficient centrifugal supercharger. What makes it different from other conventional centrifugal-type superchargers is its drive mechanism. The system receives its propulsion from a belt and pulley, just like most other superchargers. But, internally, the compressor wheel is driven by a set of different-sized planetary rollers instead a direct drive gear. Rather than being locked into a set gear ratio, the rollers allow for internal slippage, which is manipulated by oil pressure, pressing the rollers together.
All this adds up to the nearly instantaneous throttle response expected from a supercharger. But at low engine speeds, the compressor has a minimal effect on performance. This increases the longevity of both the engine and the supercharger, while at the same time minimizing fuel consumption and emissions. At higher engine speeds, the rollers tighten up for that snappy, locked-in type of mid-range boost response that turbochargers just can't keep up with (since the compressor wheel is smaller than most conventional centrifugal superchargers).
The experience behind the wheel is surprising. The boost ramps up so smoothly that it can't be discerned at all. The engine feels stock at cruising speeds. Then, as the tachometer moves into the fun zone, the engine appears to grow in displacement.
The tight confines of our autocross-style test course made it difficult to really evaluate the car's at-the-limit handling characteristics. However, there was one third-gear corner where we could mash the throttle and really hang the rear end out. Once sideways, the naturally aspirated-like throttle response could really be appreciated. Adjusting the rear wheel speed and slip angle was easy, and this allowed Editor-in-Chief Leh to get the photo below on our first and only pass.
On the short autocross, the HKS Hipermax III suspension has enough stiffness for quick transitions and drifts, while retaining a streetable ride.
HKS also had a couple of Infiniti G35 Coupes and FX35 SUVs for sampling. By no coincidence, they are also powered by the same VQ35DE unit as the 350Z. The engine's ubiquity is why HKS chose it as the first application for its GT supercharger. These platforms also fall within the right balance of performance, luxury and cost. The smooth and nearly silent operation of the HKS GT supercharger is inherent with the internal roller design and can really be appreciated in these cars.