Legendary Nissan Stagea R34 Sleeper Wagon with 13B Rotary Engine Swap

The Legendary Nissan Stagea R34 and its 13B Intake Manifold

The Nissan Stagea is a station wagon that was produced from 1996 to 2007 exclusively for the Japanese market. However, the Stagea has gained a cult following globally, particularly the R34 variant which was made from 1999-2002.

The Stagea R34 is beloved by tuners and enthusiasts for its powerful RB26DETT inline 6-cylinder twin-turbo engine which also powered the legendary Nissan Skyline GT-R. With some modifications like a bigger turbo, intake, and exhaust, the humble Stagea can put down some serious horsepower.

The 13B Rotary Intake Manifold Swap

One of the most popular engine swaps for the Stagea R34 is to replace the factory RB26 inline 6 with a 13B rotary engine from the Mazda RX-7. The 13B is a high revving turbocharged rotary engine which is considerably lighter than the stock RB26.

To complete the 13B swap, an intake manifold adapter must be fabricated to mount the rotary engine in the engine bay. This allows the use of the stock Stagea intake and turbochargers with the rotary powerplant.

Benefits of the 13B Rotary Swap

There are several benefits to performing the 13B swap in a Stagea R34:

• Less weight over the nose improves handling
• Higher revving motor provides a rush of power
• Rotary engines respond well to modifications
• Easier to achieve high horsepower goals

With the right tuning and supporting mods, a built 13B rotary engine can reliably produce over 1000 horsepower in a Stagea. This kind of power is difficult to achieve with the stock RB26 without expensive internals.

Downsides of the 13B Swap

While the 13B swap seems enticing, there are some downsides to consider as well:

• Rotary engines are less fuel efficient than the RB26
• Require premixing oil for lubrication
• Rotary engines have higher maintenance costs
• Less low-end torque than the twin turbo RB26

The rotary's thirst for fuel and oil can make it impractical for a daily driven Stagea. The RB26 is the easier, more reliable choice for those looking for a usable sleeper wagon.

Building the Intake Manifold

Fabricating a properly functioning intake manifold for a 13B swapped Stagea takes some skill and the right tools. Some key steps include:

Design

First, design a manifold that bolts to the 13B's throttle body and mates with the Stagea's front mount intercooler piping. This may require custom flanges and adapters to be CNC machined.

Fitment

Test fit the intake manifold and make adjustments so there is proper clearance around the engine bay. Ensure the intake path optimizes airflow.

Fuel Rail

Weld on a fuel rail that lines up with the 13B's injectors. Braze in fittings to connect the oil and fuel lines.

Coatings

Powder coat or ceramic coat the manifold to protect from heat and prevent icing. This improves drivability.

Properly finishing the manifold takes time and skill for optimal performance and durability.

Tuning the Rotary Powered Stagea

Once the 13B engine is mounted and plumbed into the Stagea, the real fun begins with tuning the rotary beast. Some tips for maximizing power include:

ECU Tuning

Get the engine running smoothly first, then tune the ECU for bigger injectors, increased boost, and optimal ignition timing.

Fueling Upgrades

Upgrade the fuel pumps and injectors to feed the turbo rotary's thirst for gasoline octane.

Boost Control

Add an electronic boost controller and upgrade wastegates for getting the most from the snaily turbos.

Intercooling

Improve intercooling to reduce intake air temperatures for denser air charge and more power!

With some experienced rotary tuning, that modified 13B Stagea will absolutely demolish some tires and put down beastly dyno numbers!

Unleashing the Ultimate Street Sleeper

While the Nissan Stagea R34 flew under the radar as just another station wagon, adding a high-strung 13B engine transforms it into a street sleeper unlike any other. With a well-designed intake manifold and proper tuning, the rotary-swapped Stagea becomes a tuner's ultimate sleeper weapon.

So next time you see a nondescript Stagea wagon roll by, listen closely for the tell-tale sound of the 13B's tri-lobe fury coming from under the hood. You may have just witnessed one of Japan's greatest Q-car creations!

FAQs

What is a 13B engine?

The 13B is a high performance rotary engine made by Mazda that was used in cars like the RX-7 and RX-8. It is an iconic turbocharged triple rotor motor beloved by tuners for its rev-happy character.

Why swap a 13B into a Nissan Stagea?

The lightweight and high revving 13B engine allows the Stagea to make much more power than the stock RB26 inline 6. With less weight over the front axle, handling is also improved.

What kind of power can a 13B make in a Stagea?

With supporting mods and proper tuning, the 13B rotary engine can reliably produce over 1000 horsepower in the Stagea chassis. Enthusiasts have pushed them to 1200+ HP.

Is the 13B swap worth it?

For maximum power potential, absolutely. The tradeoff is higher running costs, less low end torque, and more maintenance than the stock RB26. Not ideal for a daily driver.