All Hail The Demon King RX-7 – Speedhunters


As I touched on in my recent Fujita Engineering shop tour, 99% of the magic that goes into building a rotary engine comes from the mechanic. It takes mechanical aptitude and skill, backed by years of experience and acquired knowledge to tune high-power, reliable rotary engines.


The 1% that remains can be attributed to parts, and the list is long so I’ll put it at the bottom of the page. As you’ll see, the vast majority of parts are FEED’s own creations, but back in the ’00s when they were winning trophies, those components were probably in development stages.


Despite all the modifications made and the performance on tap – 550PS at 6,600rpm and 68kg/m at 6,100rpm on 1.2bar/17.6psi boost – the Demon King is still very much a road car. Not because the ride is compliant or because its Sonic TI muffler is kind to the neighbours, because they aren’t. It remains a pleasure to drive on the road because Fujita-san has managed to retain all the creature comforts, like ABS, air conditioning, a radio, and a full interior (including carpet) that all looks brand new.


All this is at no sacrifice to performance, I can assure you. Fujita-san has managed to keep the A/C system by moving the intercooler back slightly, which, while the cores for the intercooler, radiator and condenser sit vertically, they all have plenty of space between them for air to circulate. That attention to detail is evident right throughout the car; testament to the fact that Fujita-san knows not just how to build a rotary engine, but also a complete FD3S RX-7.


Production of the FD3S chassis stopped in 2002, but it continues to evolve in the hands of tuners like Fujita-san to this day. Every detail and component of this car has been tested, refined, tested and refined again. From the engine to the cooling system, suspension to aero, Fujita-san has made it his life-long mission to perfect the RX-7.


I arrived at the FEED workshop in the afternoon, after only a phone call earlier in the morning to confirm, and even though Fujita-san was busy around the shop with various customer cars, he still agreed to take the Demon King out for a drive. Tracking from the back of a Mazda Bongo, it really was something special to see this car on the road. As I instructed Fujita-san from the back of the Bongo with hand signals only, the acceleration and poise of the RX-7 was staggering. I only had to point at where I wanted him to be and he was there in an instant. Building or driving cars, he really is a pro.

Toby Thyer
Instagram _tobinsta_

A note from the author: While these shoots look like fun and the photos are ultimately rewarding, behind the scenes was a different story. Lugging camera equipment through train stations, fields and industrial estates is hard graft, as is hanging out the back of a Mazda Bongo. This shoot was my last over the weekend before catching the evening flight back home. Unfortunately, I arrived at Kansai International Airport five minutes late and missed my flight. After waiting a couple of hours for the next flight, I arrived at Tokyo Narita after midnight, with no Narita Express to get me home. Needing to be at work in the morning, I took a local train into Tokyo Central and then another to Shinagawa – still nowhere near home. By this time it was well past 1:00am, so I jumped in a taxi for the remaining two-hour journey. While trundling down the expressway there was suddenly a loud explosion; the rear driver’s side tyre had ruptured for no apparent reason. The elderly taxi driver and I sat in the taxi while he called road-side assist, and the police, while cars and trucks hurtled past us with horns blasting. There was no hard shoulder so we sat, hazard lights blinking, waiting for the cavalry to arrive. Finally, the police showed up, as well as my new taxi. When I arrived at my local station at 3.30am, the new driver explained that the entire fare would be free. Every cloud has a silver lining, right? So, whenever I look back at these FEED stories, I’ll think gratefully about the $200 taxi fare I dodged and remind myself to always be early.

Mazda RX-7 related stories on Speedhunters

Fujita Engineering’s ‘Demon King’ 1997 Mazda RX-7 (FD3S)

Engine: FD3S Mazda 13B-REW, FEED Spec Five side-port, Skill 3-piece apex seals, FEED balanced rotors, 8.5:1 compression ratio, FEED GT3582R turbo kit, FEED offset-mount intercooler kit, FEED throttle body & adapter, FEED Sonic TI muffler, FEED fuel rail, 1,000cc injector, 2x FEED high-flow fuel pumps, FEED aluminum triple-row radiator, HKS F-CON V Pro Ver.3.4 engine management system

Driveline: FEED reinforced FD3S 5-speed gearbox, Exedy Competition R clutch, FEED 2-way limited slip differential

Chassis/Suspension/Brakes: FEED PRO F-09 Demon King spec coilovers, FEED full pillow ball kit, FEED solid support, FEED front & rear tower bars FEED member support, FEED front frame bar, urethane bushes, Auto Exe brake rotors & pads, FEED stainless steel braided brake lines, ABS diversion

Wheels/Tyres: 18×11-inch Advan R-6 wheels, 295/30R18 Yokohama Advan A052 tyres

Exterior: Aflux front cowl Ver2 Type R, Aflux front blister fender kit, Aflux rear blister fender kit, Aflux carbon aero bonnet, Aflux front canard set, Aflux GTII-R rear wing, Aflux Gurney flap HID foglight kit, Aflux dry carbon rear gate, Aflux carbon side steps, Aflux front carbon diffuser

Interior: Bride Gita Demon King spec seats, Nardi Classic 330mm steering wheel, HKS EVC6-IR boost controller, Pivot boost gauge, FEED shifter boot, FEED heavyweight shift knob, FEED e-brake boot