The RB26DETT engine is a 2.6L Inline-6 engine manufactured by Nissan, for use primarily in the 1989-2002 Nissan Skyline GT-R. The RB26DETT engine block is made from cast iron, and the cylinder head is made from aluminium. The cylinder head contains 24 valves (4 valves per cylinder), and uses a dual overhead camshaft setup. The intake of the RB26DETT varies from other RB-series motors in that it has six individual throttle bodies instead of a single throttle body. The engine also uses a parallel twin turbo system. The turbo system is arranged so that the front turbo is powered by the front 3 cylinders, and the rear turbo is powered by the rear 3 cylinders. The turbo chargers are of equal size, and are set by the wastegates to limit boost pressure to 10 psi, although the Skyline GT-R has a built in boost restrictor to keep boost under 14 psi.
The first 2.6 L RB26DETT featured twin-turbochargers and produced around 280 HP (206 kW) @ 6800 rpm and 260 ft•lb (353 N•m) @ 4400 rpm. The last series of the RB26DETT produced 280 PS (206 kW) @ 6800 rpm and 289 ft•lb (392 N•m) @ 4400 rpm. However, several stock (unmodified) engines have been dyno tested and reported to obtain closer to the 330 HP mark. The reason for this discrepancy is a gentlemen's agreement between Japanese automakers to limit theadvertised horsepower of any vehicle to 280 PS (276HP). It is widely known for its strength and extreme power potential. It is not uncommon for 600 hp to be achieved without modification of the engine internals. With regular maintenance, many of these engines have been driven way past the 100,000 mile mark with a few heading toward 200,000 miles. With extreme modification, the RB26 motor is capable of power in excess of 1 megawatt (or over 1,340 hp).
RB26DETT Camshaft duration 240°in, 236°ex lift: 8.58mm in, 8.28mm ex RB26DETT N1 Camshaft duration 240°in, 236°ex lift: 8.58mm in, 8.28mm ex
There is a common oiling problem with the pre-1992 R32 RB26 motors, as the surface where the crank meets the oil pump was machined too small, eventually leading to oil pump failure at high rpm. This was fixed for later versions of the RB26. After market performance parts makers also make oil pump extension drives to rectify this problem.
Originally the R32 GT-R was planned to have a 2.4L RB24DETT, and compete in the 4000 cc class (in Group A rules, the displacement is multiplied by 1.7 if the engine is turbocharged). This was when Nismo was going through the process of designing the R32 GT-R to be a Group A race car. But when the engineers added the AWD system, it would make the car heavy and less competitive. Nismo made the decision to make the engine a 2.6L twin turbo, and compete in the 4500 cc class, resulting in the RB26DETT known today.
The RB26DETT was used in the following cars:
- Nissan Skyline GT-R R32
- Nissan Skyline GT-R R33
- Nissan Skyline GT-R R34
- Nissan Stagea 260RS
- Tommy Kaira ZZ II