We shared Prime Motoring‘s amazing 2014 Scion FRS project in 2016. Back then the car was powered by a turbocharged 2.6 L RB26 inline-six connected to a Nissan R33 Skyline AWD drivetrain. Fast forward to the beginning of 2018 when the FRS received a complete makeover. Out went the Nissan powertrain and in went a turbo 2.4 L K24 inline-four with a S2000 six-speed manual transmission. The engine makes 469 horsepower to the wheels on 15 psi of boost from a Precision 6466 turbocharger and 93 octane fuel. As for why? It seems a combination of simplicity, weight savings, responsive power curve but the biggest reason is the cost of the RB.
Source: Prime Motoring FB page, @PrimeMotoring, and Flipzco via Piotr