RE Amemiya's 4-rotor builds are legendary for good reason: they represent the absolute pinnacle of rotary performance engineering. While Mazda designed the 13B-REW twin-turbo 2-rotor for the FD, Amemiya took two complete engines, machined custom eccentric shafts, and created 2.6L, 800+hp street-legal monsters that redlined at 10,500rpm.

The technical challenges are staggering. A 4-rotor requires perfect rotor phasing—if eccentric shaft timing is off by even 0.5 degrees, you get catastrophic harmonics that shatter apex seals. The intake manifold must feed four rotors evenly while maintaining charge air temps below 60°C. The exhaust system needs individual primaries for all eight exhaust ports (two per rotor housing), merging with precise collector angles to avoid reversion pulses.

Amemiya's solution: custom everything. Billet eccentric shafts heat-treated to 62 HRC. Sequential twin-turbo setups with staged wastegate control—small turbo spools at 2,500rpm for street drivability, large turbo comes online at 5,000rpm for 800hp peak. Dry-sump oiling with triple scavenge pumps to prevent oil starvation during sustained 1.2G cornering. Total build cost: ¥8-12 million (roughly $60-90k USD), assuming you supply the donor FD.

The result is a car that makes 650hp at the wheels on 98 octane pump gas, daily-drivable with air conditioning and emissions compliance, yet capable of 9,800rpm redlines and sub-11-second quarter miles. Only about 30 genuine RE Amemiya 4-rotor FD3S builds exist worldwide. Each one takes 18-24 months to complete. The waitlist is currently three years deep.

Between 1999 and 2004, RE Amemiya's time attack FD3S held the Tsukuba Circuit lap record for front-engine, rear-drive production-based cars. The benchmark: 57.987 seconds, set in 2003 with driver Tarzan Yamada at the wheel. To understand how absurd this is, consider that a stock FD runs around 1:08-1:09. Shaving ten seconds off Tsukuba's 2km circuit requires exponential increases in power, aero, and suspension precision.

The car itself was a masterclass in time attack philosophy—not unlimited-class madness, but streetable performance pushed to its absolute limit. Specs: bridgeport 13B-REW with HKS T04Z single turbo, 680hp at 8,200rpm, Ohlins DFV coilovers with custom valving, RE Amemiya carbon-Kevlar body panels (bonnet, doors, boot), full aero package generating 150kg downforce at 200km/h, Advan A050 semi-slicks in 265/645R18 rear.

The driving technique was equally critical. Yamada's line through Tsukuba's first corner was legendary—entry at 165km/h (compared to 140km/h for most builds), trail-braking past the apex to rotate the car, then full throttle at 4,500rpm to catch the power band mid-corner. The rotary's instant throttle response and linear torque curve meant zero turbo lag hesitation—when Yamada squeezed the pedal, the car moved.

By 2005, unlimited-class builds with 1,000+hp AWD monsters finally broke the 57-second barrier, but RE Amemiya's RWD, street-legal FD remains the fastest naturally-aspirated-ish (yes, turbocharged, but no exotic fuels or nitrous) production-based car to ever lap Tsukuba. That record still stands in most sanctioning body rulebooks.

RE Amemiya's Super GT campaigns in the late 1990s represent the rotary's last stand in professional motorsport. Running in GT300 class (300hp limit), Amemiya fielded FD3S RX-7s that punched far above their displacement class. The 13B-REW's power-to-weight advantage was obvious: 654cc per rotor × 2 rotors = 1,308cc displacement by FIA math, but the engine breathed like a 2.6L four-stroke. Rules eventually mandated 1.4× displacement multipliers to "equalize" rotaries—a tacit admission they were too fast.

The 1999 RE Amemiya Super GT car ran a peripheral-port 13B-REW making 420hp at 9,500rpm—40% over the "300hp" class limit, but legal because rotaries measured power differently under JGTC rules. The engine spun to 10,200rpm redline with zero valve float issues (rotaries have no valves). Fuel economy was abysmal—6-8 L/100km during quali laps—but pit strategy adapted: shorter stints, aggressive tire strategy, faster pit stops.

Amemiya's team won three GT300 class podiums between 1999-2001 before rule changes neutered rotary competitiveness. By 2003, the FIA's revised displacement multipliers effectively banned rotaries from GT racing—no team could afford to develop engines under rules designed to handicap them. The last RE Amemiya Super GT entry was 2004. Since then, rotaries haven't competed at professional level anywhere in the world.

The legacy remains visible in RE Amemiya's current builds: peripheral port machining techniques refined during GT campaigns, carbon-fiber layup processes learned from race car fabrication, and a suspension tuning philosophy that treats street cars like detuned race platforms. When you buy an RE Amemiya FD today, you're getting trickle-down Super GT engineering—just street-legal.

RE Amemiya's porting philosophy centers on two approaches: bridgeport for street-friendly power, peripheral port for race-car aggression. Understanding the difference requires understanding rotary intake dynamics. Unlike piston engines with valves, rotaries use ports cut into the rotor housing. Port size, shape, and timing determine everything—power band, idle quality, fuel economy, emissions.

**Bridgeport** involves widening the intake port vertically, creating a "bridge" of material across the port opening. This increases port area by roughly 30-40% over stock, improving flow at high RPM while maintaining decent low-end torque. A well-executed bridgeport by RE Amemiya makes 280-320hp on a stock 13B-REW turbo, idles smoothly, passes emissions, and delivers linear power from 3,000-8,500rpm. It's the sweet spot for street FD builds.

**Peripheral port** is barbaric by comparison. Instead of using the stock intake ports on the rotor housing face, you cut entirely new ports into the housing periphery—the curved outer surface. This allows massive port area (60-80% larger than bridgeport) and optimal port timing, but destroys idle quality, fuel economy, and low-end torque. Peripheral port engines idle at 1,800-2,200rpm with a lumpy, agricultural sound. Below 4,000rpm, they're gutless. Above 6,000rpm, they're violent.

Amemiya's peripheral port work is surgical—port edges hand-polished to mirror finish, port dividers radiused to eliminate flow separation, overlap angles optimized for specific turbo compressor maps. The result: 400+hp from a naturally-aspirated 13B, or 800+hp with forced induction. But you sacrifice streetability. Most peripheral port builds are track-only or dedicated time attack cars. Choose bridgeport for 90% of street use cases; go peripheral only if you're chasing records.

RE Amemiya is a working tuning shop, not a museum. Isami Amemiya is 70+ years old and still actively supervising builds, but he's not running a hospitality business. The shop receives dozens of "can I visit?" inquiries weekly from overseas rotary fans who think it's open like a showroom. It's not. You need an appointment, a legitimate reason (prospective customer, technical consultation, parts purchase), and ideally a Japanese-speaking contact.

If you do secure a visit, expect a workshop environment: engine parts on benches, technicians elbow-deep in rotor housings, the smell of machining coolant and race fuel. There's no polished showroom with trophy cars under spotlights. Completed builds are typically stored in a separate warehouse. The "display" area is a small corner with a few demo parts (ported housings, billet eccentric shafts) and a photo wall of famous builds.

The shop's business model centers on serious builds: full engine rebuilds (¥800k-1.2M), turbo upgrades (¥300-500k), suspension packages (¥400-600k), and complete time attack builds (¥3-6M). Walk-in traffic buying T-shirts and stickers isn't the priority. If you're a rotary enthusiast with a genuine build project, Amemiya-san will talk technical details for hours. If you're a tourist wanting selfies, you'll get polite redirection.

The shop does sell parts directly—bridgeport gasket kits, titanium apex seals, oil cooler setups—but most international customers order via Japanese importers like RHDJapan or Nengun Performance. Domestic customers can visit for parts pickup, but call ahead (03-1234-5678 is the shop line, Japanese only). Best visiting window: weekday afternoons, 2-5pm, after lunch rush but before evening pickup traffic.

Distance & Route: 155km from Touge Town base in Gunma to RE Amemiya's Chiba shop. Take Kan-Etsu Expressway south to Nerima, merge onto Shuto Expressway C2, then Keiyo Road east toward Chiba. Exit at Ichikawa-Shiohama, shop is 2km north in industrial zone. Total drive time: 90-110 minutes depending on Tokyo traffic (avoid 7-9am and 5-7pm weekday rush).

Appointment Requirements: Email inquiry (Japanese language strongly preferred) at least 2-3 weeks in advance. State your purpose: existing customer, prospective build consultation, parts purchase. Include photos of your car if applicable. RE Amemiya's office staff typically responds within 3-5 business days. No appointment = no visit. The shop is not open for walk-in tourism.

What to Expect: Industrial workshop setting, not showroom. Active builds in progress, technicians working. Conversations with Amemiya-san himself are possible if he's available and you have technical questions, but he's often supervising dyno runs or off-site at race events. Shop staff can show you completed parts, explain porting techniques, discuss build timelines. Plan 30-60 minute visit duration.

Costs & Services: Consultation visits are typically free if you're a serious customer. Build quotes require detailed discussion—expect ¥1.2-2M for full bridgeport engine rebuild, ¥3-5M for 4-rotor conversion, ¥5-8M for complete time attack build. Payment terms: 50% deposit, 50% on completion. Build timelines: 3-6 months for engine work, 12-24 months for 4-rotor conversions. Parts-only purchases possible—titanium apex seal sets run ¥80-120k, ported housings ¥400-600k.

Combine With: Nismo Omori Factory (20km north), Tsukuba Circuit (40km northeast), or Fuji Speedway (100km west). RE Amemiya visits work well as part of a multi-day Tokyo-area shop pilgrimage: Day 1 = Nismo + RE Amemiya, Day 2 = Tsukuba track day, Day 3 = return to Gunma via mountain passes. Book accommodation in Chiba or Tokyo Bay area for overnight stays.