The RB engine series ranged from as small as two liters up to three liters in displacement. This family of engines powered a variety of Nissan’s platforms, including the Fairlady Z (Z31), RWD Skyline coupes and sedans, other Nissan sedans and SUVS. The Skyline GT-R’S RB26DETT is the highest-performing variant of the family, although not the largest. The RB30ET engine featured a displacement of three liters and a turbocharger, but was intended for the Holden VL Commodore. It did not have the same amount of block reinforcement that the RB26DETT had, which limited its peak output. By comparison, the RB26 block was available in two additional variations. The RB26 N1 block, intended for N1 endurance racing, differs from the standard RB26 engine in the number of reinforcement ribs cast into the block. The strongest and most valuable RB26 engine, the extremely rare and coveted RB26 GT block, was manufactured for racing teams. Only 1,000 examples were cast, and they feature the most reinforcement of any RB engine. The only indicator of a GT block is a series of three raised-letter Rs cast into the side of the block.