Building the FR-S FA20 Engine with Stay Crushing, Assembling the Engine!


Next, the intake manifold, throttle body, sensors, and all of the lines for the direct injection system are installed as well.

To get additional fuel for our supercharged engine, we got Radium Engineering’s high capacity fuel kit for the low-pressure port side of the fuel system.

The kit includes large internal volume, CNC-machined from billet fuel rails and fuel lines. The rail can accommodate the stock fuel pressure damper. This is important, as it reduces the likelihood of fuel pump pulse-resonance from causing driveability issues.

The kit also has a much larger than stock crossover fuel line, as the stock part is tiny and can cause lean issues with forced induction. The kit uses top feed injectors.


We chose Deatschwerks 900cc/min injectors for the low-pressure port injection side of the engine. The injectors have high-impedance and are flow balanced at 1-2% of each other. They are E85 compatible, which is important because we plan on running E85 in the car occasionally.

The injectors came with these adaptor harnesses, so adding the Deatschwerks injectors is purely a plug and play deal.

The Radium Engineering fuel rail and lines with the Deatschwerks injectors are in place. Being able to add the factory fuel pressure damper to the rail is often overlooked and is the cause of many hard to cure driveability issues in modded cars.

Resonance in the fuel system can cause fuel pressure to rapidly drop or rise in the rail- causing tuning nightmares. To our knowledge, Radium Engineering is the only company to address the issue by allowing the factory damper or their own large capacity damper to be installed.

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