The Garrett GTX3584RS turbocharger has become a premier upgrade for the twin-turbo Mazda 13B‑REW engine, offering a proven jump in airflow capacity and thermal efficiency over the stock twins. This guide provides a detailed, step‑by‑step installation walkthrough, covering the necessary tools, modifications, tuning requirements, and realistic power expectations. Whether you are building a street‑friendly weekend car or a dedicated track machine, the GTX3584RS, when matched with proper supporting mods, can deliver a broad, usable powerband and 400–500 reliable wheel horsepower.

Tools and Materials Needed

Beyond the turbocharger itself, several supporting components and tools are required. Use this checklist to gather everything before you begin:

  • Garrett GTX3584RS turbocharger (GTX3584RS GEN II or standard – verify flange compatibility with your manifold)
  • T3/T4 divided or twin-scroll turbo manifold – 13B‑REW specific
  • Turbocharger oil feed kit (including restrictor if required, –3 or –4 AN line)
  • Oil drain line (‑10 or ‑12 AN, with proper 13B block fitting)
  • Intercooler core and piping (2.5″ or 3″ diameter, aluminum or silicone)
  • Blow‑off or bypass valve
  • External wastegate (if not using the GTX’s built‑in actuator – 44mm or larger recommended)
  • Boost controller (dual‑stage manual or electronic, e.g., Turbosmart E‑Boost2)
  • Fuel injectors (1,000‑1,300 cc/min for pump gas; larger for E85)
  • High‑flow fuel pump (Walbro 450 lph or equivalent)
  • Aftermarket ECU or piggyback system (e.g., Haltech Elite, Adaptronic, PowerFC)
  • Basic hand tools: full metric socket set (6‑point preferred), wrenches, Allen keys, screwdrivers
  • Torque wrench (range 10–80 ft·lb)
  • Jack and jack stands (or lift)
  • New gaskets and seals (manifold to turbo, turbo to downpipe, oil pan drain)
  • High‑temperature silicone sealant (for oil drain flange)
  • Catch can or PCV system (to control crankcase pressure under high boost)

Preparation Steps

Before lifting the hood, ensure a clean, well‑lit workspace. The 13B‑REW engine bay is compact; remove the battery, air box, and any aftermarket induction piping to access the turbo area. Disconnect the negative battery terminal. If the engine is cold, consider running it briefly to warm the oil – warm oil drains faster and reduces the mess.

Document the current hose and vacuum routing with photos. The stock twin‑turbo system has a complex network of airlines; labeling them will save hours during reassembly.

Removing the Old Twin‑Turbo Assembly

  1. Remove the upper intake manifold (UIM) – 8 bolts, careful of the throttle cable and vacuum lines. Set aside.
  2. Detach the lower intake manifold (LIM) if necessary for access – 10 bolts, 4 nuts.
  3. Disconnect the primary and secondary turbo downpipes from the exhaust system. Support the downpipes to avoid stressing the manifold.
  4. Unbolt the charge air pipes from the intercooler and turbo outlets.
  5. Remove the oil feed lines: two hard lines (one for each turbo) on the engine side. A 10 mm flare‑nut wrench reduces the chance of rounding.
  6. Disconnect the oil drain lines from the block – typically two rubber hoses clamped to 90° fittings on the oil pan.
  7. Unbolt the turbo support brackets (if present) attached to the engine block.
  8. Support each turbo from below and remove the four main manifold‑to‑turbo bolts (12 mm, difficult access). Lift the turbos out as a pair or individually.
  9. Inspect the manifold surface for warping or cracks. The stock cast‑iron manifold is robust but often requires milling after heat cycling.

Note: The stock studs in the manifold may snap. Apply penetrating oil (e.g., Kroil) hours before and use a stud extractor if they resist.

Installing the Garrett GTX3584RS

Turbo Manifold Considerations

The 13B‑REW block uses a unique exhaust port layout. Most aftermarket manifolds are T3 or T4 flange pattern with twin‑scroll divided entries. The GTX3584RS comes with a T3 divided inlet flange (0.82 or 1.01 A/R in the twin‑scroll version). Confirm your manifold matches – a mismatched flange will cause severe flow disruption. Popular choices are the Pineapple Racing or Banzai Racing cast manifolds, or custom stainless tubular units (e.g., ReAmemiya).

Mounting the Turbocharger

  1. Place a new manifold‑to‑turbo gasket on the manifold flange. Apply a thin layer of high‑temp copper spray to the gasket for sealing.
  2. Carefully lower the GTX3584RS onto the studs. The compressor cover orientation is critical – you want the compressor outlet pointing toward the front of the engine (or toward the driver’s side, depending on intercooler piping route). Clock the center housing by loosening the retaining bolts (if necessary) before final tightening.
  3. Install the nuts (8‑mm onto M8 studs) and torque to 25⁠–30 ft·lb in a criss‑cross pattern.
  4. If using an external wastegate, install it on the manifold’s wastegate port using a supplied 2‑bolt flange and gasket. The gate’s dump tube should vent to atmosphere or back into the downpipe.
  5. Mount the turbo support bracket (if provided) to the engine block to relieve manifold stress.

Oiling System Modifications

The GTX3584RS requires a pressurized oil feed and an unrestricted, gravity‑assisted return. The 13B‑REW originally fed the twins from the engine’s main oil gallery via banjo bolts. For the single GTX, you must supply a dedicated –4 AN feed line from the block.

  • Oil feed restrictor: Use a restrictor in the turbo oil inlet (0.040″ to 0.060″ orifice) drilled into the fitting. Garrett recommends a specific restrictor for journal bearing turbos; the GTX3584RS uses a full‑floating journal bearing and is sensitive to over‑oiling. Without a restrictor, oil will blow past the seals, causing smoke and buildup in the intercooler.
  • Oil drain: The stock turbo drain locations on the oil pan are too low for the single turbo. Fabricate or purchase a –10 AN weld‑on bung that enters the pan above the oil level. The drain line (–10 or –12) must slope continuously downward – no dips or loops.
  • Scavenge pump (optional): If the turbo sits too low relative to the pan, a mechanical or electric scavenge pump may be needed. Most street builds avoid this by using a high‑mounted turbo manifold.

Wastegate and Boost Control

The GTX3584RS can be ordered with an internal actuator (40 mm flapper) or without for use with an external gate. For a 13B‑REW making 400+ horsepower, an external 44 mm wastegate (Turbosmart or Tial) is strongly recommended. It provides more precise boost control and reduces boost creep.

Route the wastegate reference line from a pressure source on the compressor cover (or a dedicated fitting on the intercooler pipe after the throttle). Use an electronic boost controller (e.g., Haltech CAN‑Booster or Turbosmart E‑Boost2) to regulate boost with gear‑ or RPM‑based duty cycles.

Intercooler and Piping Installation

The 13B‑REW benefits from a large front‑mount intercooler (FMIC). Choose a core at least 3″ thick and capable of cooling 500+ horsepower. Popular choices include PWR or Spearco replica cores. Piping should be 2.5″ or 3″ aluminum with silicone couplers.

  1. Install the FMIC in the bumper opening, using brackets that secure it to the crash bar. Ensure there’s no contact with the radiator or condenser – leave at least 1″ clearance for airflow.
  2. Fabricate or purchase a 90° silicone elbow from the compressor outlet to the passenger‑side intercooler end tank. Use an aluminum pipe section with an integrated blow‑off valve flange.
  3. From the driver‑side end tank, run a pipe to the throttle body elbow. A rubber coupling with a T‑fitting for the MAP sensor is essential.
  4. Secure all clamps (T‑bolt style recommended) to 40 in·lb to prevent boost leaks.

Blow‑off valve: Plumb a Turbosmart Kompact EM or Forge BPV on the cold side (between intercooler and throttle). Do not vent to atmosphere without an ECU that can compensate; recirculate for a rotary street car.

Fuel System Upgrades

The 13B‑REW stock fuel system flows approximately 550–600 hp worth of fuel, but the injectors (550 cc primary, 850 cc secondary) are marginal for even 400 hp on pump gas. You need larger injectors and a higher‑flow pump.

  • Injectors: Upgrade to 1,200 cc/min (or 2,000 cc/min for E85) for the primary and secondary stages. Balanced sets from Injector Dynamics or RC Engineering are recommended. Use an adapter harness for the stock sub‑harness.
  • Fuel pump: A Walbro 450 lph (GSS341) will support up to 700 hp on gasoline. For higher power or E85, use a AEM 340‑lph or a twin‑pump setup.
  • Fuel pressure regulator: An adjustable FPR (e.g., Aeromotive 13109) is necessary if your aftermarket ECU requires a rising‑rate system. Set base pressure to 43 psi with the vacuum line disconnected.
  • Fuel lines: The stock nylon lines can handle 500 hp, but upgrading to PTFE (‑6 AN) is recommended for peace of mind, especially with E85.

ECU Tuning

The 13B‑REW’s stock ECU cannot be reprogrammed for a single turbo setup. A standalone ECU is mandatory. Haltech Elite 2500, Adaptronic e1280, or a PowerFC Commander are popular choices. Tuning goals:

  • Base maps: Start with a conservative spark map (max 18° BTDC under boost, taper to 10° near redline) and a fuel target of 11.5 AFR (gasoline).
  • Boost control: Use a solenoid‑based closed‑loop boost control – target 14–18 psi for street, up to 22 psi on race fuel.
  • Cold start and idle: Rotaries are sensitive to rich misfires during startup. Tune the enrichment tables carefully.
  • Ignition retard: The stock 13B‑REW has a split‑port ignition (leading/trailing). Leave leading plug timing 4–6° ahead of trailing; both should be retarded under boost.
  • Professional tuning: Hire a tuner experienced with the 13B‑REW and Haltech/Adaptronic. A poor tune can kill apex seals in minutes.

External links for tuning resources:

Power Expectations

On a properly built 13B‑REW with a Garrett GTX3584RS, you can expect the following at the wheels on a DynoJet:

  • 400 hp – 450 hp on 93 octane pump gas at 16–18 psi, with a conservative tune.
  • 480 hp – 520 hp on 100+ octane race gas or methanol‑water injection at 20–22 psi.
  • Torque: Peak torque of 340–380 ft·lb, arriving by 5,000 RPM and holding to 7,200 RPM – a fat, flat curve that makes the car feel much faster than the peak number suggests.
  • Spool: Expect 12–14 psi by 3,500–3,800 RPM with a divided T3 manifold and twin‑scroll housing. Full boost (18 psi) arrives by 4,200 RPM. This is a slight increase in spool speed compared to stock twins (which spool by ~3,000 RPM) but with far less IAT rise and top‑end choke.

Example dyno run (data only): At 18 psi on 93 octane, a typical 13B‑REW with the GTX3584RS (0.82 A/R twin‑scroll) makes 460 whp and 375 ft·lb, with torque exceeding 300 ft·lb from 4,700 RPM to 8,000 RPM. The power does not nosedive after peak – it remains above 440 whp to the 8,200 RPM fuel cut.

Supporting Mods That Affect Power

  • Porting: A street port (not a bridge or half‑bridge) keeps idle stable and powerband broad. Expect +30–40 whp over a stock port.
  • Exhaust: A 3″ mandrel‑bent downpipe and cat‑back – no bottleneck. A 4″ exhaust is beneficial above 500 whp.
  • Intake: A large K&N cone filter with heat shield – not a restrictive air box.
  • Cooling: A vented hood or electric fan upgrade helps IATs under sustained boost.

Reliability and Maintenance

The GTX3584RS is a journal‑bearing turbo; it requires a few simple care steps to last 50,000+ miles:

  • Oil changes: Use 10W‑40 synthetic (API SN) with high zinc content (e.g., Brad Penn or Castrol GTX 20W‑50 for warmer climates). Change every 2,500–3,000 miles. The turbo shares oil with the engine; clean oil is critical.
  • Cool‑down: After a hard run, let the engine idle for 60–90 seconds before shutdown to allow the turbo’s oil to cool and prevent coking in the center section.
  • Boost leaks: Regularly check all intercooler pipe connections and vacuum lines. A leak causes lean conditions and detonation.
  • Pre‑ignition: Never run more than the tuned boost level without retuning. Even a 1 psi overboost can cause knock.

Conclusion

Installing a Garrett GTX3584RS on the 13B‑REW turns a complex twin‑turbo system into a single, powerful, and more easily serviced setup. When paired with a quality manifold, proper oiling, a robust fuel system, and a professional tune, the result is a street‑friendly 440–500 whp with excellent throttle response and a torque curve that transforms the driving experience. By following this guide and respecting the rotary engine’s unique requirements, you can achieve a reliable high‑output build that will put a smile on your face for thousands of miles.