Nissan RB Engine - RB26DETT N1

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 RB26DETT engine experiences vibrations between 7000 and 8000 rpm. The engine also received improved water and oil channels within the engine block. The pistons and top piston rings were also upgraded to 1.2 mm. 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 ball bearing).

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 N1 engine is theoretically said to be able to produce in excess of 1,900 bhp (1,400 kW)

The Nismo RB26DETT N1 engine block uses an 86 mm bore which can be bored up to either 87 mm or 88& mm. The N1 block is stamped 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.

Only two R32 GT-R Bathurst cars were stripped after the competition. Parts were shipped back to Japan where it's believed some were sold to private parties in New Zealand and Australia.