RB26DE The RB26DE is a naturally aspirated variant of the RB26DETT made specifically for the 1992
Nissan Skyline Autech Version GTS-4 (HNR32) sedan. Mechanically, it is similar to the RB26DETT as it uses the same cylinder head, bore and stroke () and individual intakes as the RB26DETT, minus the usage of a parallel
twin-turbo system. The engine and ECU (
engine control unit) were tuned by
Autech and S&S Engineering to make at 6,800rpm and at 5,200rpm. It also has a higher compression ratio than the RB26DETT, at 10.5:1.
RB26DETT The RB26DETT engine is a
twin-turbo inline-six engine manufactured by Nissan, for use in the 1989-2002
Nissan Skyline GT-R. The RB26DETT engine block is made from cast iron, while the cylinder head is made from aluminium alloy, which contains
DOHC 4 valves per cylinder (24 valves in total) setup. The intake of the RB26DETT varies from other RB-series motors in that it has six individual (3 sets of 2 throttle assemblies that are siamesed together) instead of a single
throttle body. The engine also uses a parallel
twin-turbo system, using a pair of T25-type ceramic turbochargers set by the
wastegates to limit boost pressure to , although the Skyline GT-R has a built in boost restrictor to keep boost under . The first 2.6 L RB26DETT was rated by Nissan at around at 6,800 rpm and at 4,400 rpm. By the end of production, power levels had gone up to around at 6,800 rpm and at 4,400 rpm, not only because of developments and modifications to the engine, but also because of the "
Gentlemen's Agreement" made between automakers at the time to limit the "advertised" horsepower of any vehicle to . While the published figures from Nissan were as quoted above, it has been known among enthusiasts that the car actually had a factory power output closer to the figure. The RB26 is widely known and became quite popular for its strength and power potential thanks to its iron block and forged internals, making it a modification friendly platform for tuners and aftermarket modifications in general. Some factory features of the RB26DETT: • 6 throttle body intake • Solid lifter valve actuation, shim under bucket • Belt driven cams • CAS (crank angle sensor) driven off exhaust cam, tells ECU (
engine control unit) crank/cam position • water cooled, oil pressure lubed turbos • OEM cast pistons have cooling channels under the crowns (extra oil cooling to keep piston temperatures down) • Piston oil squirters • Sodium filled exhaust valves • 8 Counter weighted
crankshaft • 'I' beam connecting rods There is a common oiling problem with the pre-1992 R32 RB26 motors, as the surface where the crankshaft meets the oil pump was machined too small, eventually leading to oil pump failure at high rpm. This issue was resolved in later versions of the RB26 with a wider oil pump drive, which is found in all R33+ RB26 motors. Aftermarket performance parts makers also make oil pump extension drive collars to rectify this problem. More recently a spline drive solution has been developed by an aftermarket tuner Supertec Racing who moves away from the OEM flat drive system and uses splines to drive the oil pump gears in the same way as the
Toyota's 1JZ-GTE engine found in the
Toyota Supra (MK3). This kit is available for most uprated RB26 oil pumps including Nissan's own OEM, N1 and Nismo parts, although most high HP RB-series engines all over the world have been proven to be reliable without spline driven oil pumps when built and tuned correctly. Besides minor cosmetic updates and ECU fine tunings, changes were made in the R34 generation to
ball bearing T28 turbochargers as opposed to journal bearing turbos. The R34 GT-R turbos retained the ceramic exhaust turbine wheel. Models that had steel exhaust turbine wheels included the R32 Nismo, R32-R33-R34 N1 models and R34 Nür spec skyline GT-R's. R34 GT-R model RB26DETT engine specific differences to the R32-R33 engines include: • Candy red cam/coil pack covers • Different coil cover emblem • Plastic CAM gear cover • Non-painted inlet plenum (apparently also a lighter casting) •
Hitachi CAS (Crank angle sensor) has different drive fitting compared to earlier R32-R33 exhaust cams • Igniter built into coil packs (no igniter pack on the rear of coil cover) • Ball bearing turbochargers with ceramic exhaust turbine wheels • Stainless steel dump pipes • Sump front differential has a different ratio (3:55) • Different diameter coolant/heater pipes on intake side of block • Dual mass
flywheel Originally, the R32 GT-R was planned to have the 2.4 L 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 at a time when
Nismo was going through the process of designing the R32 GT-R to be a
Group A race car. However, when the engineers added the AWD system, they found that it made the car heavier than expected and as a result, much less competitive.
Nismo made the decision to make the engine a 2.6 L twin-turbo and compete in the higher 4500 cc class, resulting in the RB26DETT engine many known today. The RB26DETT was used in the following vehicles: •
Nissan Skyline GT-R BNR32 • Nissan Skyline GT-R BCNR33 •
Nissan Skyline GT-R Autech Version 40th Anniversary BCNR33 (Autech factory-installed RB26DETT and AWD 5spd transmission in R33 sedan chassis) • Nissan Skyline GT-R BNR34 •
Nissan Stagea 260RS WGNC34改 (RS4 chassis used) •
Tommykaira ZZII (concept car)
RB26DETT N1 The RB26DETT N1 is a modified version of the RB26DETT engine, developed by Nismo (Nissan Motorsports) for Group A and Group N motorsport. Nismo found that the standard RB26DETT engine required too much maintenance for use in a Group-A or Group-N race car and subsequently designed the N1 block; this was first used in Bathurst, Australia. Nismo balanced the crankshaft to a higher specification than stock, as the standard RB26DETT engine experiences vibrations between 7,000 and 8,000 rpm. The engine also received improved water and oil channels within the engine block. The pistons and top piston rings were also upgraded to . The N1 engine also has upgraded camshafts and upgraded turbochargers. Although all versions of the RB26DETT N1 engine use
Garrett T25 turbochargers, the specification of the turbochargers changed through the 3 generations of the RB26DETT N1 engine (R32, R33, and R34). The R32, and R33 versions used
Journal Bearing T25 Turbochargers. The R34 RB26DETT N1 engine used Garrett GT25 turbo chargers (which use a set of ball bearings). The biggest difference between the turbochargers used in the N1 engine, and the standard RB26DETT engine, is that the turbine wheels in the turbocharger are made from steel, rather than the
ceramic used for the standard RB26DETT turbochargers. The ceramic turbine wheels are found to be very unreliable when used at high rotational speeds inducing higher centrifugal forces (such as when the turbochargers are used at a higher boost pressure than stock). With the advances in manufacturing technology such as sealing and material processes. The Nismo RB26DETT N1 engine block uses an bore which can be bored up to either . The N1 block is cast with an identification mark of 24U, whereas the standard RB26DETT block is marked with 05U. The RB26DETT N1 block is compatible with all GT-R engine bays.
RB26DETT Z1 and Z2 The RB26DETT Z1 and Z2 (and often referred to as an "RB28DETT Z1/Z2") was the engine used in the
Nissan Skyline GT-R Z-Tune built by Nismo. It uses a stronger RB26 block based on Nissan's Le Mans GT2 and GT500 racing vehicles (stamped with RRR), stroked crankshaft, upgraded turbochargers, and a higher bore and stroke at a displacement of 2.8 L. It produces and of torque. The 'Z2' revision includes upgraded turbochargers supplied by
IHI, and additional improvements to allow it to reach maximum RPM speeds of up to 8,000 rpm. ==RB30 (3.0L I6) ==