Overview
In this guide you’re gonna learn how to make the mighty RB26 engine in Automation. I got most of the specs from various websites, and even with them, it’s a little off, so I did the best I could with this. 😛
Basic Components
This should be the final result of your build. Let’s start with the bottom end first.
An inline 6 is obviously required, make it out of a cast iron block. Bore should be 86 mm and stroke should be 73.7 mm. The valvetrain is a DOHC setup with 4 valves per cylinder, so 24 valves total.
Internals
For our engine internals, get a forged steel crank, I Beam steel conrods, and forged pistons. (Kinda bullshitted with the pistons but since hypereutectic pistons can’t go to 8000 rpm, I just went with forged.)
Compression and Cams
Since the RB26 is turbocharged, it needs a lower compression ratio, around 8.5:1. For the cams I had to play around a bit, but eventually ended up with 73 for the cam profile, and 85 for the VVL profile. I put VVT on all cams, and dragged the quality up to 15.
Turbocharger
The turbocharger setup needs ball-bearings, with a large air-to-air intercooler. For the turbo itself the compressor is 57.5 mm, the turbine 47 mm, and the AR Ratio .85. I decided to do the factory boost increase of 14.7 psi, up from 10 which would give the engine its JDM limit of 276 hp. Quality is 15.
Fuel and Air
Multipoint EFI is what i decided on for fuel delivery. The 26 has individual throttle bodies, so select that option, along with the performance intake and premium fuel. Mixture is at 12.3:1 and ignition at 77. Redline is 8000, and quality is at 15 again.
Exhaust
Since we have a turbocharger, which runs off of exhaust gases, we need short cast headers. Single exhaust and no bypass valves. 3.25″ diameter. Regular 3-way catalytic converter, and both mufflers should be reverse flow.
Aesthetics and End
Congratulations! You made an engine!
Now onto making it look like an RB motor.
Pick the valve cover style like this:
and making it red.
Now go out there and fight some 2JZs!
(this is my first guide, I’d appreciate any feedback if this gets any)