About RWB - RAUH-Welt Begriff

RWB / RAUH-Welt BEGRIFF is a Porsche tuner located in Japan.
RWB has combined Japanese and Euro tuning elements,
creating the distinct RWB style for Porsche chassis.
Starting off as a small countryside body-shop in Chiba-Ken,
RAUH-Welt 911’s are now a common sight on both the streets and racing circuits of Japan.

Founded by Akira Nakai-San in the 90’s. RAUH-Welt Begriff translated means “Rough World Concept”. Most famous for their signature wide-body air-cooled Porsche’s and the manner in which Akira Nakai installs each kit personally on site.

About Akira Nakai-San - The RWB founder

Akira Nakai is a Japanese car tuner and the founder of Porsche tuning company RAUH-Welt BEGRIFF (RWB), which specializes in the design and installation of custom wide-body kits on older Porsche models.

Akira Nakai’s career got started with a drift crew called Rough World, from there he started to work on Porsches while employed by a body shop when he came across a damaged one and got his hands on it in the late 90s.

Nakai later started his own company called RAUH-Welt Begriff (RWB)

Building an RWB Porsche

A big factor in why a RWB Porsche is so sought after is the fact that you cannot simply install an RWB kit yourself, the Kit is personally installed by RWB founder – Akira-Nakia

A kit is ordered and shipped to you and then after a waiting period, Akira-Nakia will fly to your location and do the conversion

Head over to our RWB Builds page for more info

How many RWB Porsche's are there?

We are busy trying to track down all of the RWB Porsches.

To do this we have had to start out side of Japan and try locate all the RWB build done across the world once we have this number we will try and get information on the amount of RWB builds in Japan

We will try an maintain our registry and keep it as up-to0date as possible, although with Akira-Nakia building close to 100 RWB Porsches a year, we have certainly got our work cut out.

Type of RWB Kits

there are a number of RWB kits Available  across 3 Porsche 911 platfoms – the 930, 964 and the 993.

Although it as seen as there are 4 RWB options the 964 is used in both the wide body and narrow body RWB 911 build

Each customer can uniquely put pieces of their kit together and add extra body parts to suit their desired RWB build.

RWB Porsche 930 Wide Body

This wide body kit for the Porsche 911 (930) is what started it all. The legendary “Stella” car owned by Nakai-san himself is a RWB 930 Wide Body.​

RWB Porsche 964 Wide Body

An evolution of the 930 RWB kit featuring the same aggressive fender flares and wing. This variant receives different front and rear bumper styles to complement the rest of the car.

RWB Porsche 911 Narrow Body

This RWB body kit is designed for street use offering owners of the Porsche 964 a more tame, “narrower”, wide body style.

RWB Porsche 993 Wide Body

The RAUH-Welt Begriff 993 Body Kit is the widest, most aggressive of them all

RWB Porsche 997

Although not officially unveiled or complete yet, we have seen a few teasers of the new RWB 997 body style, this will be the first water cooled RWB Porsche

What does an RWB kit consist of?

An RWB kit typically consists of a new front bumper, rear bumper, side skirts, wheel arches, spoilers and suspension setup.

Customers can add and choose extra parts to build the car in a way that suits them or for a specific purpose

RWB Documentaries

We have found a few RWB documentaries for you to enjoy, these are video’s that go more in-depth into the RWB culture and all of its components

Visit the offical RWB Site

For more information and contact options to the official RWB Website

Idlers 12 hour race

The Idlers 12 hour race is a grassroots racing event located in Japan and is held at the Twin Ring Motegi race track

The idlers 12 hour race has a rolling start; you follow the Twin Ring Motegi pace car for one whole lap and once you hit the very last corner you floor it.


The Idlers Club was founded by Atsushi Seike, who’s also editor of the Idlers magazine and a Japanese 911 magazine.

The Idlers 12 Hour Race has been a constant on the Japanese motorsports calendar since 2000.

The idlers 12 hour race is a way for Nakai to emphasis his style, which has always been tightly linked to motorsport.

There is also a drift component to the Idlers event – RWB has some RWB Toyota AE86’s competing.