Marugen Shoukai: The story behind the world's BEST FRP body parts for 240Zs

Shiratori san operates the aero company Marugen Shoukai in Muroran, Hokkaido.

In his youth, he built and raced Hokkaido’s fastest Fairlady Z S30. While many during the time, and even now, ran N/A Carbureted setups, he preferred Fuel injection and Twin Turbos. While it is much more involved to get the most out of this type of setup, it rewards those who have the patience to find the sweet spots when tuning. Shiratori san is detail oriented tinkerer who loves making small adjustments to get the best possible outcome and due to having this type of personality turbos were a great choice. To this day, he still has a bunch of built turbo L28 engines sitting in his shop.

Many challengers tried to take him and his mighty Z down, but all fell short. On the street, challengers, who often spent two or three times the amount he spent to build their cars, made all types of excuses about why they lost but when you go to the track, all that matters is the time. On the Hokkaido zeroyon stage (0-400m is the quarter mile drag race in Japan), Shiratori san and his Z became the undisputed champions as proven by his dust covered trophies.

Much of the drag racing happened on the street in the 90s but after a car lost control and injured spectators in the gallery, the police clamped down on street racing. After giving up racing, he decided to turn his attention to detail towards making super high quality fiberglass parts.

From high-spec drag race S30Zs to high-end 240ZG restorations, his parts have been installed on all types of cars. His shop is also an absolute car maniac’s dream: From several home built CNC machines and lathes, to endless toolboxes and mountains of dead stock Nissan/Nismo parts that he purchased before ceasing production (some for his own car as well as bases for creating his FRP products).

The quality of his products is undeniable. For the majority of his catalog there are three types: Standard, Deluxe and Special.

Standard is the basic quality item. He skips no steps in terms of the mold making process but less fiberglass is used when producing the parts which in turn, results in a lighter product. Perfect for racers whose focus is not fit and finish but performance.

Deluxe is the middle of the range. More attention is paid to the amounts of fiberglass used in key areas such as mounting points and areas that receive stress at speed.

Special is the top of the range in terms of quality. This is where Marugen Shokai differentiates from all others. OEM Nissan and NISMO items are examined and analyzed to determine what materials were used, thickness of the items and why certain decisions were made in production. Chopped strand mat is not used where Nissan chose to use woven mat. Inner and outer molds are made and the completed parts are sandwiched together to get the desired fit and finish. No detail is missed.

When comparing the special type G-nose to an OEM one, it is incredibly difficult to tell the difference. The attention to detail paid to the hardware for fitment/adjustment, reinforcement ribs, and thickness in key areas makes it easy to understand why his parts have no equal anywhere in the world. He’s also the only one in the world to produce Urethane front bumpers for the 240ZG G-nose. 

Often, to maximize profits, parts manufacturers literally cut corners when making molds. They use cheap materials, skip important steps to make quality molds and sell the parts cheap. To the end user, it’s difficult to understand the difference between a 600 dollar G-Nose and a 3,000+ dollar one but believe me when I tell you, the money is worth it. Your body shop will thank you for paying the extra money for quality. They’ll have less work to do, the work will be finished faster, and the parts will last MUCH longer. 

Shiratori san is an extremely knowledgeable resource for all things Z related and I am extremely thankful that I was able to spend some time with him while learning about what he does at Marugen Shoukai.

I am very excited to be able to offer his Marugen Shokai 240Z parts on Final Heaven and will definitely be fitting some of his parts to the Final Heaven project Z (details coming soon)! If there are parts you don't see on the website but wish to order, feel free to contact us about them. Anything he makes, we can order!