2JZ vs RB26 Comparison: Boosting to 650+ HP Using Greddy and Tial Wastegates

The Toyota 2JZ-GTE and Nissan RB26DETT are two of the most legendary six-cylinder engines in automotive history. Both have powered iconic platforms — the Supra MK4 and the Skyline GT-R — and both have earned a reputation for handling massive power with proper modifications. Enthusiasts routinely push these engines well past the 650-horsepower mark, often using premium boost control components like Greddy and Tial wastegates. This comparison dives deep into the architecture, strengths, and tuning paths required to hit that 650+ HP target with either engine.

Engine Architecture and Block Strength

The foundation of any high-horsepower build is the engine block. Both the 2JZ and RB26 are inline-six configurations with cast-iron blocks, but their design philosophies differ significantly.

2JZ-GTE Block

The 2JZ-GTE uses a closed-deck cast-iron block with thick cylinder walls and a deep skirt design. This construction is extremely rigid and can handle 1,000+ horsepower on stock internals in many cases. The 3.0-liter displacement provides a strong torque baseline, which helps spool large turbochargers. The factory crankshaft is forged steel, and the connecting rods are forged as well in later versions. For 650+ HP, the stock block and bottom end are more than sufficient with a proper tune and fuel system upgrade.

Many builders simply upgrade the head studs and install a stronger head gasket.

RB26DETT Block

The RB26DETT also uses a cast-iron block but with a smaller 2.6-liter displacement. The block is a closed-deck design, though the RB26’s cylinder walls are thinner than the 2JZ’s relative to bore size. The stock crankshaft is forged, but the connecting rods are weaker cast units. For 650+ HP, RB26 owners typically need to upgrade rods and often pistons, especially if running high boost on larger turbos. The smaller displacement also means more reliance on boost and rpm to reach power targets.

The RB26’s block is still robust, but it requires more careful preparation at the 650 HP level than the 2JZ.

Cylinder Head Differences

The cylinder head design directly affects airflow potential, which is critical for high-horsepower builds.

2JZ-GTE Head

The 2JZ head features a reverse-flow design with the intake ports on the exhaust side, which limits flow compared to modern crossflow heads. However, the head has ample material for porting. Stock valve sizes are adequate up to about 700 HP, but larger valves and a port job become beneficial for higher power levels. The head uses a timing belt drive, which is reliable but requires periodic replacement. The camshafts are modest from the factory; aftermarket camshafts with around 264–272 degrees duration help free up top-end power.

RB26DETT Head

The RB26 head is a crossflow design with intake and exhaust on opposite sides, offering better flow potential out of the box. It features dual overhead camshafts with variable valve timing (VCT) on later versions. The stock ports are quite good, and many RB26 builds only need mild porting for 650+ HP. The valve sizes are slightly smaller than the 2JZ, but the superior port architecture often compensates. However, the head is prone to cracking between valve seats if overheated, which is a known weakness when pushing high boost for extended periods.

Upgraded head studs and a multi-layer steel head gasket are mandatory at this power level.

Stock Turbo System vs. Aftermarket Upgrades

Both engines came from the factory with twin-turbo setups, but the configurations differ.

2JZ-GTE Sequential Turbos

The 2JZ uses sequential twin turbos: a small primary turbo for low-rpm response and a larger secondary turbo that comes online around 3,500 rpm. While this system is impressive for daily driving, it becomes a bottleneck above 400 HP. For 650+ HP, nearly all builders convert to a single large turbocharger, such as a Garrett GTX3582R or Precision 6266. The sequential system is removed entirely, and a new exhaust manifold, downpipe, and wastegate setup is required.

RB26DETT Parallel Turbos

The RB26 uses two identical turbochargers in parallel, each feeding three cylinders. This setup can support up to about 500–550 HP with upgrades like higher-flow compressor wheels and steel exhaust housings. However, for 650+ HP, most RB26 builds either upgrade the twins with larger units or switch to a single turbo. The RB26 engine bay is tight, making single-turbo conversions more challenging but still popular. The stock ceramic turbine wheels are fragile; replacement with steel wheels is essential when raising boost.

Wastegate Selection: Greddy vs. Tial

Boost control is paramount when targeting 650+ HP. A high-quality wastegate ensures stable boost pressure, prevents overboost spikes, and helps manage exhaust backpressure. Two of the most trusted brands are Greddy (Trust) and Tial.

Greddy Wastegates

Greddy wastegates have been a staple in the Japanese performance market for decades. They use a diaphragm-actuated design with adjustable spring pressure. The Greddy Type R wastegate is a common choice for high-power builds. Key benefits include:

  • Compact size: Fits in tight engine bays, important for RB26 and 2JZ single-turbo conversions.
  • High flow capacity: The Type R flows enough for 800+ HP setups without excessive backpressure.
  • Reliable spring mechanism: Springs are color-coded for easy identification and swapping.
  • Cost-effective: Generally cheaper than Tial while still offering excellent performance.

Greddy wastegates work particularly well on street-driven cars that need predictable boost response. However, the diaphragm material can degrade over time if exposed to high backpressure from very large turbos.

Tial Wastegates

Tial is an American brand that has become the gold standard in high-performance boost control. Their MV-R and MV-S series wastegates are engineered with aerospace-grade materials and a robust billet construction. For 650+ HP, the Tial MV-R 44mm or 60mm wastegate is common. Advantages include:

  • Precision machining: Tighter tolerances reduce leakage and improve boost control accuracy.
  • Advanced diaphragm: Tial’s silicone diaphragms resist heat and backpressure better than older rubber designs.
  • V-band or flanged options: Easy to install and service on custom manifolds.
  • Proven durability: Used in professional racing and time attack series worldwide.

Tial wastegates are favored for track-oriented builds where consistent boost at high rpm is critical. The downside is higher cost compared to Greddy, but many builders consider it a worthwhile investment for reliability.

Supporting Modifications for 650+ HP

Hitting 650 horsepower requires more than just a turbo and wastegate. Both engines need a comprehensive upgrade package.

Fuel System

At 650 HP, fuel demand roughly doubles from stock. A Walbro 450 or 525 lph fuel pump, 1,000+ cc injectors, and a return-style fuel system are necessary. For ethanol blends (E85), larger injectors and stainless fuel lines become mandatory.

Engine Management

Factory ECUs cannot handle the required fuel and timing adjustments. A standalone system like a Motec M130, Haltech Elite 2500, or AEM Infinity provides full control. On the 2JZ, a simple plug-and-play solution like the AEM EMS Series 2 is common. For the RB26, the Haltech Elite is popular due to its support for VCT and throttle-by-wire.

Intercooling and Cooling

To manage intake temperatures, a large front-mount intercooler (3.5–4 inch core) is essential. Both engines benefit from upgraded aluminum radiators and oil coolers. The RB26 specifically needs an upgraded oil system due to its oil pump and oil pressure challenges at high rpm.

Drivetrain

650 HP will destroy stock transmissions and differentials on both platforms. The 2JZ is often paired with a Getrag V160/V161 six-speed manual, but these are expensive and can still fail with aggressive driving. Many 2JZ builds use a GM 4L80E automatic or a Tremec Magnum. For the RB26, the stock Getrag 5-speed (R34) is marginal; a G-Force 5-speed or a sequential is common.

Real-World Build Examples

Looking at actual builds helps contextualize the differences.

650 HP 2JZ Build

A typical 650 HP 2JZ single-turbo setup uses a Garrett GTX3582RS with a 0.82 A/R T4 divided housing, a Tial MV-R 44mm wastegate, 1,000cc injectors, a Walbro 450 pump, and a Haltech Elite 2500. Power comes on by 3,800 rpm and pulls hard to 7,500 rpm. The car often weighs around 3,300 lbs and runs low 11-second quarter-mile times on pump gas.

650 HP RB26 Build

An RB26 reaching 650 HP typically uses a single Precision 6266 or a BorgWarner S366 with an 0.91 A/R housing. Wastegate choice is often the Tial MV-R 44mm. Supporting mods include CP-Carrillo forged rods, JE pistons, a ported head with 264 cams, and a Haltech Platinum Pro. The powerband is shifted higher (peak at 7,200 rpm) due to smaller displacement. Weight is around 3,400 lbs, with similar quarter-mile times but often a higher trap speed due to better gearing and aerodynamics of the GT-R.

Cost Comparison

Building either engine to 650 HP requires a significant budget.

  • 2JZ-GTE: A used engine can be found for $4,000–$8,000. A complete build including turbo, manifold, wastegate, fuel system, standalone, and labor often runs $15,000–$25,000. The lower cost of 2JZ internals (stock block is sufficient) can save money.
  • RB26DETT: A used RB26 is more expensive — $6,000–$12,000 — because of demand and rarity. Forged rods and pistons add $2,000–$3,500. Total build cost can reach $18,000–$30,000. The RB26’s more complex turbo setup and transfer case in the GT-R add to labor costs.

Both are expensive, but the 2JZ offers a better power-per-dollar ratio for 650 HP targets.

Which Engine Is Right for Your Build?

The choice between 2JZ and RB26 for a 650 HP goal largely depends on the vehicle platform and your preferences.

  • If you are building a Supra MK4 or swapping into a lighter car like an IS300 or FC RX-7, the 2JZ offers easier power, simpler plumbing for a single turbo, and lower overall cost.
  • If you want the iconic AWD system of a GT-R or the unique character of the RB26 engine, the RB26 is rewarding but requires more careful tuning and internal upgrades at the same power level.
  • Both respond well to Greddy and Tial wastegates; choosing between them usually comes down to budget and personal preference on boost control feel.

Conclusion

The 2JZ-GTE and RB26DETT are both exceptional engines capable of 650+ horsepower with the right modifications. The 2JZ has a stronger factory bottom end and larger displacement, making it easier and often cheaper to reach the target. The RB26, while smaller, offers a high-revving character and a legendary pedigree, especially when paired with the Skyline's advanced drivetrain. In both cases, choosing a high-quality wastegate from Greddy or Tial is critical to achieving consistent boost control and reliability at high power levels. Whether you favor sequential or parallel turbos, single conversions, or factory twins, the path to 650 HP is well-trodden for both engines — but each demands respect for its specific weaknesses.

With proper planning, both will deliver unforgettable performance.

For further reading, consult resources like the SupraForums and GTR Forum for detailed build threads, or manufacturer pages for Tial Wastegates and Greddy to compare product specifications.