Introduction: The Legendary 13B‑REW and Its Aftermarket Potential

The Mazda 13B‑REW is one of the most iconic rotary engines ever produced. Its compact twin‑rotor design, high‑revving nature, and unique sound have earned it a devoted following among enthusiasts and tuners worldwide. Factory‑equipped in the third‑generation Mazda RX‑7 (FD3S), the 13B‑REW comes with sequential twin turbochargers, but its performance potential far exceeds stock levels. With the right aftermarket parts, these engines can reliably produce 400 to 700+ wheel horsepower while maintaining street manners. However, selecting high‑quality components is critical—rotary engines have specific thermal and fueling requirements that differ from piston engines. This guide covers the best brands for 13B‑REW performance parts, starting with the two heaviest hitters: Garrett and BorgWarner.

Garrett Motion – The Gold Standard in Turbochargers

Garrett has been a leading manufacturer of turbochargers for decades, and their products are a staple in the 13B‑REW community. Their turbos are known for precise manufacturing, robust bearing systems, and wide compressor maps that suit both street and track applications. For rotary engines, Garrett’s ability to deliver high flow at moderate boost pressures makes them a top choice.

GTX Series

The GTX line represents Garrett’s latest generation of high‑performance turbos. Key features include:

  • GTX3076R Gen II – A popular upgrade for the 13B‑REW that supports 400–550 hp with quick spool. The dual ball‑bearing cartridge reduces lag significantly compared to journal‑bearing units.
  • GTX3582R Gen II – For those targeting 500–700 hp. The 58mm inducer and extended tip compressor wheel deliver excellent top‑end airflow while still responding well on the rotary’s exhaust pulses.
  • GTX4088R – A monster frame ideal for high‑boost race setups, capable of 700+ hp. Paired with a proper fuel system and standalone ECU, it transforms the RX‑7 into a serious drag or time‑attack machine.

The GTX series uses Garrett’s patented aero‑technology (aerodynamic compressor wheel and turbine design) to achieve up to 5% better efficiency than older GT series turbos. This means less heat soak and more consistent power during prolonged runs.

GT Series (Legacy but Proven)

Garrett’s GT series remains a reliable workhorse. The GT35/40 and GT42 have been used for decades in rotary builds. While they lack the modern aero refinements of the GTX line, they are still widely available and often more budget‑friendly. Many street‑driven 13B‑REW cars run a single GT3582R (non‑Gen II) with great success, especially when using a divided T4 housing to match the rotary’s split exhaust pulses.

Key consideration: Garrett turbos pair exceptionally well with large mandrel‑bent downpipes and V‑band exhaust setups. For the 13B‑REW, a 3‑inch exhaust is the minimum for any performance build.

BorgWarner Turbo Systems – Engineering for Competition

BorgWarner’s aftermarket division produces turbos that have earned a stellar reputation in endurance racing and time‑attack events. Their EFR (Engineered For Racing) series is particularly well‑suited to the 13B‑REW, thanks to features designed specifically for high‑efficiency, fast‑spooling applications.

EFR Series

  • Lightweight Gamma‑Ti turbine wheel – Made from a titanium‑aluminide alloy, the turbine wheel reduces rotational inertia by about 30% compared to a standard Inconel wheel. This allows the EFR to spool faster on the rotary’s low‑rpm exhaust flow, a common challenge for single‑turbo conversions.
  • Integrated bypass valve – The EFR housing includes a recirculating bypass valve that reduces compressor surge and helps maintain boost control when lifting off the throttle. This is particularly beneficial for street cars that see mixed driving conditions.
  • Dual ball‑bearing center housing – BorgWarner uses a high‑speed ball bearing assembly with a stainless steel turbine housing. The result is quicker transient response and better tolerance to the high exhaust temperatures (up to 1050°C) common on rotary engines.
  • EFR 8374 – One of the most popular sizes for the 13B‑REW. It supports 450–600 hp and provides excellent mid‑range torque. The 1.05 A/R divided T4 housing matches the twin‑scroll characteristics of the stock exhaust manifold (if retained) or a custom twin‑scroll header.
  • EFR 9180 – A larger frame for 550–700+ hp builds. It requires a larger T6 flange or custom piggyback adapter, but rewards with top‑end airflow exceeding 75 lb/min.

BorgWarner’s forged milled compressor wheels and extended tip technology reduce turbulence and improve efficiency across the entire map. Many professional rotary shops recommend the EFR series when the goal is crisp drivability plus high peak power. The main trade‑off is cost—EFR turbos are typically more expensive than equivalent Garrett or precision units.

Other Notable Brands for 13B‑REW Performance Parts

Beyond the turbo itself, building a reliable high‑power RX‑7 requires supporting components from trusted aftermarket manufacturers. Here are several additional brands that produce top‑tier parts for the 13B‑REW.

Apex Engineering

Apex Engineering is a Japan‑based company that focuses exclusively on rotary engines. Their parts are designed with racing reliability in mind. Key offerings include:

  • Intake manifolds – Cast aluminum plenums with integrated velocity stacks that improve airflow distribution across the two rotor housings. Apex’s long‑runner design boosts low‑end torque for street cars, while the short‑runner version suits high‑rev applications.
  • Exhaust housings – Ported and polished irons and housings that eliminate casting flash and improve exhaust flow. Apex also offers billet corner seals and side seals for high‑boost builds.
  • Oil cooler kits – Direct‑fit 19‑row oil coolers with thermostatic sandwhich plates. Proper oil cooling is critical on rotaries to prevent thermal breakdown of the seals.

HKS

HKS is one of the most recognized Japanese performance brands, and they have a long history with the FD3S chassis. Their 13B‑REW parts are engineered for plug‑and‑play installation:

  • SSQV blow‑off valves – The Super Sequential Valve offers adjustable spring tension and a recirculation option. It prevents air surge when closing the throttle, protecting the compressor wheel.
  • Intercoolers – HKS’s Type S and Type R intercoolers feature bar‑and‑plate cores with cast end tanks. They are sized to fit behind the FD’s front bumper without major modification, handling up to 500 hp efficiently.
  • F‑Con ECUs – While older, the HKS F‑Con V Pro piggyback can still be found; standalone options from Haltech or MoTeC are now more common, but HKS wiring harnesses and boost controllers remain popular.
  • Turbo kits – HKS once offered complete twin‑turbo upgrades (with GT2530s) and single‑turbo conversion kits using Garrett cores. These are less common now but still can be sourced used.

Greddy (Trust/GReddy)

Greddy, also known as Trust in Japan, produces comprehensive performance kits that minimize guesswork. Their offerings include:

  • Turbo kits – The GReddy T67 (T04Z variant) and T88 single‑turbo kits are legendary in the rotary world. They come with divided manifolds, downpipes, wastegates, and all necessary hardware. The T67 kit is ideal for 400‑500 hp street builds; the T88 targets 600+ hp.
  • Intercooler kits – GReddy’s 3‑row intercooler for the FD3S uses a 600 hp core and includes polished aluminum piping and silicone couplers. It drops right in with no core cutting required on the bumper support.
  • Oil cooler and catch can systems – High‑capacity oil coolers and dual‑chamber catch cans that prevent oil vapor from entering the intake tract—a must for rotaries to keep carbon buildup away from the apex seals.

Racing Beat

Racing Beat is an American company that has specialized in rotary performance since the 1970s. They are known for exhaustive research and development on the 13B‑REW:

  • Exhaust systems – Racing Beat’s True Dual Rev2 exhaust uses a 3‑inch system with high‑flow race cats or cat‑delete pipes. The design carefully balances scavenging for both rotor ports, increasing mid‑range torque without sacrificing top‑end power.
  • Intake systems – The Racing Beat RAM air intake and intake duct kits route cold air from the front bumper to the stock airbox or aftermarket filter. Their velocity stack adapters for the airbox provide smoother airflow than stock.
  • Suspension components – While not directly performance parts for the engine, Racing Beat’s sway bars, end links, and strut bars improve chassis rigidity, which helps with power delivery and stability at high speed.

Additional Brands Worth Considering

  • Precision Turbo & Engine – Their PT62 (6262) and PT66 (6766) turbos are popular choices for budget‑minded rotary builds. They offer journal and ball bearing options, and the 6262 can support up to 550 hp with quick spool. Precision also provides wastegates and blow‑off valves.
  • Turbonetics – Their T‑Series turbos (e.g., T‑70, T‑76) have been used in older high‑boost rotary setups. The Spin Series features ceramic ball bearings for reduced lag and higher thrust capacity.
  • Injector Dynamics – High‑impedance fuel injectors that are essential for ethanol or high‑boost fuel systems. ID1050X or ID1300X injectors are common choices for 500‑700 hp rotary builds. They provide linear flow curves that simplify calibration.
  • Bosch Motorsport – The Bosch 044 fuel pump is the gold standard for external in‑line fuel pressure on rotary engines. They also offer EV14 injectors and fuel pressure regulators.
  • Haltech – While not a parts manufacturer in the traditional sense, Haltech engine management (Nexus R5, Elite 1500, etc.) is highly regarded for controlling the 13B‑REW. Sequential injection, per‑rotor ignition timing, and advanced start‑up tables are fully supported.

Choosing the Right Parts for Your Build

Selecting performance parts for a 13B‑REW is not a one‑size‑fits‑all decision. The engine’s unique eccentric shaft and rotor housing layout require careful matching of forced induction, fuel, and engine management. Follow this structured approach to make informed choices.

Define Your Power Goals and Use Case

  • Street weekend car (300‑400 whp): Consider a single turbo upgrade in the Garrett GTX3076R or BorgWarner EFR 7670 range. Use a moderate single‑scroll divided T4 manifold, keep compression stock (approx. 9.0:1), and pair with a tuned standalone ECU. Stock fuel pump upgraded to 550cc/min secondaries (or larger ID injectors) is sufficient.
  • Street/strip (400‑550 whp): Move to a GTX3576R or EFR 8374. Upgrade fuel injectors to 1000cc/min or larger. Add a surge tank and inline Bosch 044 fuel pump. Increase oil cooling capacity—add an aftermarket oil cooler with at least a 19‑row core. Use a larger intercooler (Greddy or HKS 3‑row).
  • Track/competition (550‑750 whp): GTX3584R, EFR 9180, or Precision 6766. Switch to a T4 divided twin‑scroll manifold for better pulse separation. Install a fuel cell or high‑flow surge tank with two 044 pumps. Run water/methanol injection or E85 to keep intake temperatures low. Use a Haltech or MoTeC ECU with a wideband lambda and map‑based boost control.

Supporting Mods Are Non‑Negotiable

The 13B‑REW’s apex seals and side seals are sensitive to detonation and overheating. Every performance build must include:

  • Fuel system upgrades: High‑flow pumps (Walbro 450 or Bosch 044) paired with a pressure regulator and larger injectors. The factory fuel rails can be reused if you upgrade the lines to -6AN or larger.
  • Engine management: A standalone ECU (Haltech, MoTeC, Adaptronic, AEM Infinity) is mandatory for any turbo upgrade. The stock ECU cannot control larger injectors or different boost levels safely.
  • Oil cooling: Add a dedicated oil cooler with a thermostat and ducting. Oil temps over 130°C (266°F) will accelerate seal wear. Use synthetic 10W‑40 or 15W‑50 racing oil (Rotary specific blends from Motul or Idemitsu recommended).
  • Ignition system: Replace the leading and trailing coils with high‑energy units (HKS Twin Power, GReddy ignition amplifiers, or OEM‑upgraded coils with new spark plug wires). Proper ignition prevents misfire under high cylinder pressures.

Do Not Overlook Tuning

Even the best parts will fail without a proper tune. Rotary engines have a narrower window of safe air/fuel ratios than piston engines (typically 11.5‑12.0:1 under boost, 14.7:1 at idle). Excessive lean mixtures can cause immediate apex seal failure. Work with a tuner who has specific 13B‑REW experience. Many reputable rotary shops offer remote calibration services for Haltech and MoTeC platforms.

Conclusion

The Mazda 13B‑REW remains one of the most rewarding engines to modify, thanks to the extensive aftermarket support from brands like Garrett, BorgWarner, HKS, Greddy, Racing Beat, and many others. Whether you are building a daily driver with 350 whp or a track‑focused monster exceeding 700 whp, there is a proven combination of turbo, fuel system, and engine management components available. Invest in quality parts from reputable manufacturers, ensure your supporting systems are properly sized, and always prioritize tuning. Done correctly, a 13B‑REW build will deliver an exhilarating driving experience that few other engines can match. For further reading, check out resources from Garrett Motion, BorgWarner Turbo Systems, and Racing Beat for product specifications and application guides. Your journey from stock to‑stout starts with the right parts. Choose wisely, and enjoy the build.