Top Secret: Smokey Nagata's Shop and the 197 MPH Gold Supra Legend

In the late 1990s, a Japanese tuner named Kazuhiko "Smokey" Nagata drove a heavily modified gold 1995 Toyota Supra MK4 on a British motorway and reached 197 mph (317 km/h) on public roads, as documented by Japanese automotive video magazines. The entire run was filmed on Japanese television. When Nagata returned to Tokyo several days later, British police released warrants for his arrest and his Supra was impounded at Heathrow Airport. Nagata was fined £250 and the Supra was shipped back to Japan.

That stunt, broadcast in the Japanese car show "Video Option," made Top Secret — Nagata's Tokyo tuning shop — world-famous. Over 30 years later, Top Secret remains one of the most iconic Japanese aftermarket performance shops, specializing in Toyota Supras, Nissan GT-Rs, and ultra-high-HP street cars.

The Founder: Smokey Nagata

Kazuhiko "Smokey" Nagata was born in 1957. His nickname comes from his cigarette smoking habit (he's been photographed hundreds of times with a cigarette in his mouth, often while working on cars). He grew up obsessed with Japanese domestic sports cars and started modifying them in his 20s.

In 1993, Nagata founded Top Secret in Chiba, Japan (a Tokyo suburb). The shop specialized in building extreme high-HP Supras, Skylines, and other Japanese sports cars for wealthy clients who wanted street-drivable cars with supercar-killing performance.

Nagata's engineering philosophy is "no limits." He believes in pushing engines past their factory specifications until they either hold together or fail — and then rebuilding them to be even stronger. His cars routinely exceed 1,000 HP, and his most famous build, the Gold Supra (V12), had a custom-built 1GZ-FE V12 engine swapped in from a Toyota Century, producing over 900 HP.

The Gold Supra M4 Run

The 197 MPH run on the M4 motorway is the defining moment of Top Secret's legend. Here's what happened:

The car: A 1995 Toyota Supra MK4 Twin Turbo (J-spec), painted gold, with a built 2JZ-GTE producing approximately 950 HP at the crank. Engine modifications included:

• Forged pistons and rods
• Upgraded HKS GT3037S turbocharger
• Custom intercooler and fuel system
• Standalone engine management (HKS F-CON V Pro)
• Upgraded transmission (Getrag V160 with reinforced gear set)

The location: A British motorway — the precise road has varied in subsequent retellings, but contemporary accounts agree it was an overnight run on an uncrowded section of motorway in the UK. The road was mostly empty but not completely — there was occasional traffic.

The run: Nagata drove the Supra from London heading west. He gradually built up speed on an empty stretch of motorway. A camera crew in a chase car filmed the speedometer and the passing landmarks. At peak, the Supra hit 197 mph (317 km/h). Nagata's commentary throughout the run was calm and professional, explaining in Japanese that he wanted to demonstrate what a tuned Supra could do on real-world roads.

The aftermath: The footage was broadcast on Video Option magazine's TV segment in Japan. Within days, British police had identified Nagata and issued warrants for his arrest. He returned to Japan before being apprehended, but the Gold Supra was impounded at Heathrow Airport. Nagata eventually paid a fine (reports vary: £250, £500, or more), and the Supra was returned to Japan after several months.

The video went viral worldwide in the early days of automotive YouTube. It established Top Secret as the shop that could build a real 197+ mph street car.

Signature Builds

Top Secret V12 Gold Supra

Nagata's ultimate build. A Supra MK4 with the 5.0L 1GZ-FE V12 engine from a Toyota Century swapped in. Required extensive custom fabrication — new engine mounts, custom driveshaft, modified transmission, and extensive firewall modifications to fit the longer V12 in the engine bay. Output: over 900 HP naturally aspirated.

The V12 Supra appeared in the first season of the Grid Autosport video game and was featured in numerous magazines. It remains one of the most famous custom Supra builds in history.

Top Secret R34 GT-R Drag Build

A heavily modified R34 Skyline GT-R with a built RB26DETT producing approximately 1,200 HP. Used for quarter-mile drag racing in Japan. Ran mid-8-second quarter miles at over 170 mph.

Top Secret FD3S RX-7 20B Conversion

A rare build: Top Secret swapped a 20B-REW three-rotor engine into an FD3S RX-7 chassis, creating a 3-rotor RX-7 producing approximately 500 HP. Featured in Best Motoring and Hot Version videos.

Signature Products

Top Secret Body Kits

Visually distinctive aero kits for Supra, GT-R, and FD3S RX-7. Usually feature exposed carbon fiber, aggressive front lips, and flared fenders. The "Top Secret" nameplate on a car is an instant indicator of serious tuning work.

Top Secret Suspension Systems

Coilover kits for street and track use, known for progressive spring rates and aggressive valving.

Top Secret Exhaust Systems

Stainless steel full-system exhausts with characteristic large tips. Loud, but well-engineered for power.

Top Secret Titanium Intake Plenums

For 2JZ-GTE and RB26DETT applications. Hand-formed titanium, lightweight, and distinctive visually.

Why Top Secret Matters

Top Secret represents the "no compromises" philosophy of Japanese tuning. Nagata isn't interested in making a 400 HP daily driver for a magazine cover — he wants to build 1,000 HP street cars that can actually be driven on highways and still be reliable enough to maintain. This focus on extreme street performance, combined with Nagata's willingness to publicly demonstrate his builds (even on illegal motorway speed runs), made Top Secret the archetype of Japanese tuner outlaw culture.

Today, Top Secret still operates from its Chiba workshop. Smokey Nagata continues to appear in Japanese car magazines and occasional YouTube videos. The shop primarily builds custom Supras, R35 GT-Rs, and occasional R34 GT-R restorations. A visit to Top Secret in person is a pilgrimage for serious JDM enthusiasts.