Getting a RWB-Style Widebody on a Porsche
RWB stands for Rauh-Welt Begriff, which is Akira Nakai's Japanese custom shop. They don't make kits. They hand-build every car in-house, usually in Japan, and the waiting list runs years. Most people looking at RWB Porsche The Art Of Customization And Performance want the look and the track capability without going through Nakai himself. That's fine, but you need to understand what you're actually dealing with before you start buying fenders. The RWB aesthetic centers on bolt-on wide fenders, usually fiberglass or polyurethane, paired with massive Fuchs-style wheels tucked into those arches. The performance side is typically an air suspension setup, a mild engine tune, and sometimes a full turbo conversion on older 964 or 993 chassis. The whole point is stance, low cornering speed, and making a 350-horsepower car look like it should be doing 600. That tension between appearance and function is what drives every decision in these builds. If you're building from scratch, the first thing most people get wrong is the wheel fitment. RWB's signature look depends on specific offset and width combinations. A typical 964 setup runs 18x9.5 up front and 18x12 in the rear with about 30-35mm of spacers. If you change that, the whole visual balance shifts. The fenders look wrong, the stance changes, and suddenly you're just building a regular widebody Porsche instead of something that reads as RWB-inspired.
The Build Process
Start with the suspension. An air ride system from AirBFT, AST, or even a properly set up KW V3 with adjustable camber plates gives you the foundation. RWB cars sit low, usually 1-2 inches lower than stock, and that changes how the wide fenders align with the wheels. Get the ride height dialed in before you bolt anything to the body. The fender packages come from several sources. Real RWB conversion parts are available through licensed reproductions like RWB USA or independent fabricators, but they're expensive and still require significant customization. Budget alternatives exist from companies like Gunther Werks replicas or various Chinese fabricators, but the fitment can be inconsistent. I'd recommend starting with one car or one fender piece to test fit before committing to a full set. The fiberglass tends to warp slightly during shipping and needs trimming regardless. Mounting the fenders requires cutting the existing body panels. On a 964, you remove the front bumper, take out the original fenders, and weld or bolt on the wider sections. The rear is more involved because the 993 and 964 have different attachment points depending on whether you have the M64 engine swap or the original flat-six. Use a digital caliper and check measurements at every step. The tolerances are tight, and if your fenders aren't sitting flush with the door gap, everything looks off even if you can't immediately say why.
Engine and Performance Considerations
Most RWB-inspired builds stay relatively mild on the power side because the cars are already light. A stage one tune through a reputable ECU flash or standalone management like a Link or MOTRON gives you maybe 30-50 extra horsepower on a naturally aspirated 964 M64, which pushes things into the 350-400 range. That's usually sufficient for street use and weekend track days. If you're doing a turbo conversion, be aware that the RWB look was originally designed for naturally aspirated cars. The wide fenders accommodate bigger wheels for aesthetics, not necessarily for tire choice under heavy boost. A 964 turbo build with RWB bodywork is entirely possible but you're working against the original design intent. The cooling packages need to be reconsidered, and the weight distribution changes affect how the air suspension should be set up. Brakes are another area people overlook. Wider fenders often mean you need to move up to bigger brake rotors, which means checking if your wheel choice actually clears them. I had a customer who installed 18x12 rear wheels with a 964 turbo brake upgrade and found out too late that the rotors hit the inside of the wheel at full lock. The workaround was switching to a different wheel offset and using brake caliper covers, but it added cost and time that could have been avoided with upfront planning.
Get the Full Details
Common Pitfalls
The biggest mistake is underestimating the paint and finish work. RWB fenders are rarely pre-painted, and even when they are, the color matching is approximate. You'll need professional paint work to get a result that looks intentional rather than like a body shop mistake. Budget an additional $3,000-8,000 for proper paint depending on your location and the level of finish you want. Another issue is the weight of fiberglass fenders compared to factory steel. A full set of RWB fenders adds roughly 30-50 pounds over the factory panels. On a 964 that's already around 2,800 pounds curb weight, that's noticeable but manageable. On a lighter 993 or a track-focused build where every pound matters, it affects handling balance. You may need to adjust the air suspension spring rates or dampener settings to compensate.
Cost Breakdown
A realistic RWB-style conversion on a 964 or 993 Porsche runs between $15,000 and $40,000 depending on your approach. The fender package alone is $3,000-8,000. Air suspension adds $4,000-7,000. Paint and labor $3,000-8,000. Wheels and tires $3,000-6,000. Engine work varies wildly based on what you're doing. If you're working with a project car that already has mechanical issues, factor in those repairs separately. The build only gets more expensive if the car isn't running properly before you start. If your budget is under $10,000 total, you're better off focusing on a clean suspension and wheel upgrade without the widebody. A well-suspended stock-body 964 with quality wheels and brakes will drive better and cost less than a half-finished RWB conversion that sits ugly and handles poorly.
