Tsuki: The Evolution of Tegiwa’s Honda NSX
When a car becomes more than just a machine, it tells a story of passion, innovation, and relentless pursuit of performance. For Tegiwa, our Honda NSX known as Tsuki is exactly that—a testament to automotive engineering and racing ambition.
The Beginning: 2019
Our journey with our NA1 Honda NSX began in 2019 when the car arrived at Tegiwa as a rolling shell, perched precariously on ill-fitting steel wheels. At this point, it was nothing more than a potential canvas waiting to be transformed.
First Steps: Endurance Racing
While the NSX would have originally left the factory sporting its iconic C-Series V6 engine, we made a deliberate decision to deviate from this path. The original power plant, though legendary, presented significant challenges for our racing ambitions. Limited aftermarket support meant sourcing performance parts would be difficult, and the engine’s substantial weight would compromise the car’s dynamic potential. Instead, we opted for a standard K20 engine sourced from a Civic Type R. This choice allowed us to go endurance racing, laying the groundwork for what was to become an extraordinary machine.
Time Attack: First Successes
As we ventured into Time Attack, things quickly escalated. A Skunk2 Racing K24 engine was built, delivering a potent 320 naturally aspirated horsepower. This precision and power saw us take the Time Attack Club 2WD class in 2020—our first significant milestone.
Pro 2WD: Stepping Up the Game
2021 marked our entry into the bigger leagues of Time Attack. The Pro 2WD class, bringing with it slick tyres, increased power and more aero. A Rotrex supercharger transformed the NSX, and it was during this period that the car earned its name, Tsuki, complemented by a striking new livery that captured its evolving character.
Collaboration and Innovation: 2022
The year 2022 introduced us to Terry Radbourne of Bourne HPP, a pivotal moment in Tsuki’s evolution. His development of the K22 ‘boost’ engine was groundbreaking, with a larger supercharger pushing power to approximately 570 horsepower.
Aerodynamic Revolution: 2023
2023 saw dramatic transformations. A partnership with Andrew Brilliant of AMB Aero resulted in comprehensive aerodynamic upgrades—a carbon splitter, false floor, side skirts, and an extraordinary rear wing. The result? An astonishing 1,500kg of downforce at 150mph—theoretically enough to drive upside down.
The engine received equally impressive upgrades. State-of-the-art Pankl pistons, which are the thickest known on a K-Series engine, were integrated into the K-Series engine, essentially bringing Formula 1 technology into our build. Darton wet steel lined sleeves required extensive machining, while an Arrow Precision crankshaft, weighing just 12kg, was designed to reliably spin to 9,500rpm with minimised vibration.
Our efforts culminated in clinching the 2023 Time Attack Pro crown after a nail-biting final session of the season, a moment of pure triumph.
2024: Pushing Boundaries Further
The evolution continues. A Route KS wide body kit dramatically altered the NA1 silhouette, allowing us to run massive 305 wide slick tyres on 11J WedsSport TC-105X wheels. A new livery complemented these aggressive modifications.
The turbocharger evolved from a Garrett G30-770 to a more potent G35-900, remarkably maintaining a minimal 400rpm loss on the torque curve’s lower end.
A Holinger MF-2WD 6-speed sequential gearbox now manages the immense power, supported by Ohlins TTX40 MKII coilovers and Eibach race springs—a fully independent, 4-way adjustable suspension system.
Our development at Multimatic’s shaker rig revealed fascinating insights, including the somewhat humorous fact that Tsuki is now 12.18 times more uncomfortable than a 1998 Mercedes S class!
A Pace Products Dry Sump system ensures optimal oil circulation, maintaining engine efficiency even in the most extreme cornering conditions.
The Journey Continues
Tsuki is more than a car—it’s a rolling testament to engineering passion, a machine that embodies our relentless pursuit of performance. But make no mistake: this journey is far from over. In fact, for 2025 we will be running a Cylinder Support System K-Series block. In the world of motorsport, there is no such thing as a “finished” car. Each season brings new challenges, new technologies, and new opportunities to push the boundaries of what’s possible.
Our commitment remains unwavering. Year after year, we will continue to innovate, to refine, and to seek that next incremental gain. Whether it’s squeezing out an extra few horsepower, reducing weight, or finding new aerodynamic efficiencies, Tsuki will continue to evolve. The goal is simple yet endlessly complex: to go faster, to be better, to redefine the limits of what a modified NSX can achieve.
Tsuki is not just a project car—it’s a never-ending quest for automotive perfection. And we wouldn’t have it any other way.
