Ultimate Guide to Turbocharger Kits for Mazda 13B Rotary Engines

Introduction to 13B Turbo Kits

For rotary engine enthusiasts, turbocharging the 13B engine is a popular way to increase horsepower and performance. The 13B is the 1.3 liter twin-rotor Wankel rotary engine designed by Mazda, originally released in the Mazda Cosmo in 1967. Over the years, the 13B has powered numerous Mazda vehicles including the iconic Mazda RX-7 and RX-8 sports cars. With a high revving nature and compact size, the 13B is an ideal candidate for turbocharging. In this article, we'll take a closer look at 13B turbo kits and provide an overview of turbocharger options, supporting mods, and potential power gains.

Benefits of Turbocharging the 13B

There are several benefits to adding a turbocharger to the 13B engine:

• Increased horsepower and torque output
• Enhanced throttle response and reduced turbo lag
• Higher RPM capabilities
• Improved efficiency through increased air density
• Greater tuning potential for big power gains

With the right supporting mods and turbo kit, it's possible to safely increase the horsepower of a stock 13B by 50% or more. For example, a stock non-turbo 13B-REW engine in the 1993-1995 RX-7 FD makes around 250 horsepower. With a properly tuned single turbo setup, power output can be increased to 350 horsepower or beyond.

Turbocharger Options

There are a few main options when selecting a turbocharger for a 13B turbo kit:

Single Turbo

A single turbo setup uses one larger turbocharger plumbed to the intake and exhaust. This provides great top end power while still offering good low end response. Popular single turbo options for 13B engines include Garrett GT28-71R and GT30-76R turbochargers.

Sequential Twin Turbos

Sequential twin turbo systems use two differently sized turbochargers working together - a smaller one for low end response, and a larger one that comes on at higher RPMs for top end power. This helps reduce turbo lag off idle while still reaching big power numbers up top.

Parallel Twin Turbos

Parallel twin turbo kits utilize two equally sized turbochargers plumbed in parallel. This doubles the airflow while reducing turbo lag compared to a single turbo setup. However, it is a more complex setup and can be harder to properly tune.

Supporting Modifications

When adding a turbocharger to a 13B, supporting engine mods are highly recommended to handle the increased stress and airflow. Here are some top supporting mods to consider:

Engine Management

A stand-alone ECU or piggyback system is required for proper turbo tuning and engine control. Popular options include Haltech, AEM, Hydra, and Cobb tuners.

Fuel Delivery

Upgraded fuel injectors and fuel pump are needed to supply additional fuel required under boost. Rotary engines also benefit from port injected systems rather than standard side feed injectors.

Ignition System

Higher output coil packs and upgraded spark plugs help optimize ignition timing under boost. An ignition timing controller can also help.

Intercooler

A front mount intercooler improves intake air charge cooling compared to the stock side mount intercooler. This increases power and reduces risk of detonation.

Exhaust Manifold

Proper exhaust manifold design optimized for the selected turbocharger is crucial for spool and power delivery. Tubular stainless steel manifolds are popular upgrades.

Oiling System

Upgraded oil pumps, Accusump systems, and oil coolers help maintain proper rotor housing lubrication under elevated boost pressures.

Clutch and Drivetrain

The increased power output will require upgraded clutch discs and flywheels rated to handle the torque. Improved axles and differentials may also be needed.

Potential Power Gains

With supporting mods and proper tuning, turbo 13B engines can safely achieve significant horsepower gains. Here are some examples of turbo 13B power output:

• Stock 13B-REW (1993-1995 RX-7 FD): 250hp -> 400+hp
• Street ported 13B: 280hp -> 450+ hp
• Bridge ported 13B: 300hp -> 500+ hp
• Built 2-rotor: 400hp -> 650+ hp

These are just estimates - exact power gains will depend on factors like turbo selection, engine build specs, tuning, and other modifications. With the right setup, 600 to 700+ horsepower is achievable from a built 13B turbo rotary engine.

Important Tuning Considerations

Properly tuning any turbo 13B engine build is crucial to maximize performance and reliability. Here are some key tuning tips:

• Slowly increase boost in small increments - don't get overzealous with big boost spikes right away.
• Monitor engine vitals like air/fuel ratios, coolant temps, detonation, etc.
• Adjust fuel delivery based on wideband O2 sensor feedback to stay safe.
• Reduce timing and increase fuel in increments if detonation is observed.
• Make sure oil and coolant temperatures are within acceptable parameters.
• Always retune for any new modifications or changes to the setup.

It's highly advised to work with an experienced rotary tuner when turbocharging any 13B. Tuning issues can quickly lead to dangerous levels of detonation and damage if not properly addressed. Patience and diligent tuning practices will pay off with big power and many happy miles of boosted rotary driving!

Conclusion

When properly executed, adding a turbocharger to the 13B can transform the rotary's performance to exhilarating new levels. With so much potential, it's no mystery why turbocharged 13B engines are so popular with Mazda rotary enthusiasts. The combination of compact size, high RPM power, tunability, and that signature rotary sound is hard to beat. We've just skimmed the surface of 13B turbo kits here, but hopefully this provides helpful insight into the possibilities that await. If you're considering boosting your 13B, do your research, choose reputable parts, and work with an experienced rotary shop. The results will put an ear-to-ear grin on your face every time you step on the throttle!

FAQs

What is the most popular single turbocharger choice for a 13B?

The Garrett GT3076R is one of the most popular and reliable single turbocharger options for street-driven 13B engines. It provides a great balance of spool, response, and top end power capability.

What type of fuel system upgrades are needed for a turbo 13B?

Larger fuel injectors and higher capacity fuel pumps are the minimum fuel system upgrades required. For big power goals, a port fuel injection system and bigger surge tank are recommended.

What transmission upgrades should be done when turbocharging a 13B?

The stock transmission can handle moderate power increases, but anything over 400hp will require a stronger clutch, flywheel, axles, and diferential to handle the torque.

Is an aftermarket ECU required for a 13B turbo build?

Yes, a standalone aftermarket ECU or piggyback system is highly recommended over the stock ECU for proper tuning control and monitoring under boost.

What are the most important things to monitor when tuning a turbo 13B?

Key things to monitor are air/fuel ratios, ignition timing, coolant and oil temperatures, and knocking/detonation. This ensures safe operating parameters are maintained.