The Nissan RB20 belongs to a class of engines called “RB.” They range in size from 2.0L to 3.0L. The RB20 is a four-stroke engine that uses standard gasoline. It was produced by Nissan between 1985 and 2004.
There are two versions of this engine, which are an SOHC and a DOHC. Both have an aluminum head. While the SOHC versions have two valves in each cylinder, the DOHC versions have four valves in every cylinder.
Nissan RB20: Origins
The design for this engine comes from the L20A engine, which was its six-cylinder predecessor. The RB shares some commonalities with the original model, such as stroke and bore, but many other specs are different from the L20.
The RB engine was produced in Japan. Different variations of the RB20 include:
- RB20DE NEO
- Production Run: 1984 – 2002
- Cylinder Head Material: Cast Iron
- Cylinder Block Material: Cast Iron
- Configuration: Inline Six
- Bore: 78mm
- Stroke: 69.7mm
- Valvetrain: SOHC and DOHC Variants
- Displacement: 1,998cc (2.0L)
- Compression Ratio: 8.5:1 (RB20DET)
- Dry Weight: 584lbs (Complete engine w/ transmission, no fluids)
- Max HP: 93hp – 212hp
- Max LB-FT: 105lb – 195 lb-ft
- Oil Capacity: 4.8 quarts
The RB20E is the first engine in the series. It features a single-cam technology and a power output of 129-148 HP at 5,600 RPM. The R20ET received the addition of a turbocharger for more power.
Its maximum power output was 168 HP at 6,000. The RB20DE features a twin-cam design and a power output of 148-153 HP at 6,400 RPM. The turbo-charged RB20DET has a power capacity of 212 HP at 6,400 RPM.
The RB20P, with 12 valves and a single-cam design, is the only one to use liquefied petroleum gas (LPG). It gets 93 HP at 5,600 RPM. The RB20DET-R produces 207 HP at 6,400 RPM. Finally, the RB20DE NEO generates 153 HP.
Nissan RB20: Applications
This engine is unique for its turbo-charged capacity and direct fuel injection technology. It was a popular choice for many Nissan vehicles during the time of its production. The engine appears on the following cars:
- HR31 Skyline
- Fairlady 200ZR
- Holden Commodore
The RB20 was installed in many of Nissan’s vehicles produced from the 1980s through early 1990s. It gained popularity among consumers and mechanics for its ample rev-matching capacity.
The engine was relatively simple too, which made it easy to customize. A short camshaft design and exceptional build quality are other features that made it a hit.
Nissan RB20: Tuning Potential
Despite its benefits, the engine is not entirely problem-free. One complaint is that it lacks decent torque below 4,500 RPM. This problem can be fixed by adding in aftermarket camshafts and a larger turbocharger, amongst many other aftermarket modification which can aid in the addition of low-end torque.
To save money, installing mild camshafts on the engine with its original turbocharger significantly boosts its power output. Another problem that the engine is known for is its oil system.
The ignition coils can also fail, which in turn causes the engine to misfire. All things considered, however, this engine has relatively few issues compared to other engines on the market today.
There are a number of viable options available for upgrading the turbo in this engine. Some brands that stand are Garrett and HKS. Keep in mind that no matter which one you choose, the maximum pressure you should boost your turbo to is 11.5 psi.
For a sportier performance, the HKS Sport Turbo line has good options. One standout upgrade is the 2530kai that produces 350-360 HP. This horsepower is achievable by making other modifications too, including ECU tuning and upgrading the camshafts.
Another good choice for this engine is the 2530. It is a smaller turbocharger that doesn’t require extensive modifications. By simply swapping out the original turbocharger with the 2530, you’ll get a nice boost of power and a more responsive engine.
Garrett, which produces the engine’s original turbocharger, naturally has a wide selection of alternative turbochargers to choose from. Because the company made the original components, it is a good brand to choose if you want a close match with your current engine.
Even so, the best Garrett turbocharger should be selected based on the specific engine you have, as only the right size turbo will produce optimal performance.
Along with these turbo upgrades, you can also use a turbo booster kit. These kits, which are produced by Trust, have a bolt-on design to facilitate installation. Along with the turbocharger itself, they come with gaskets, lines, a wastegate, and a new manifold.
Depending on the specific version you get, your turbo kit may come with additional features for a complete upgrade. For the RB20DET engine, one of the most highly recommended kit is the TD06-20G.
Along with the turbocharger, the engine can be modified for enhanced performance with fuel injectors, a GTR intercooler, a downpipe, a three-inch straight pipe exhaust system, spark plugs, a turbo boost controller, and a fuel pump.
Walbro 255 and GTR are recommended brands for the fuel pump. To reach 450 HP, you’ll need MLS head gaskets, head studs, and enhanced camshafts.
RB20 vs RB25
The RB25 succeeded the original engine. This brought improvements in terms of power and performance. There are four engines produced in this series. Two have twin-cam turbochargers, and the other two had a twin-cam design without a turbocharger.
The newer engines are designed to provide Nissan’s vehicles with more power and torque at a lower RPM than the previous line. This is accomplished by introducing ignition coils with integrated ignitors, a revised air flow meter, a throttle position sensor, and other modifications.
In 1998, a special head was outfitted to the engine to make it qualify as a low-emission vehicle.