Subaru WRX STI may get a 2.4-litre turbo boxer engine

KUALA LUMPUR: WRX STI, the flagship sports car from Japanese automobile manufacturer Subaru, is all set for a major upgrade for its 2021 model year. Sources close to the company have revealed that the next-generation WRX STI will be hauled by an all-new, 2.4-litre turbocharged boxer engine, called the FA24. The motor produces around 400 bhp and 361 lb-ft peak torque. The output of the car will be significantly bolstered from the current version which produces 304 bhp and 311 lb-ft peak torque.

The present Japan-specification Subaru WRX STI is hauled by a tuned and tweaked version of the 2.0-litre turbocharged boxer engine which powers the Impreza WRX. The engine is also known as the EJ20 in motoring circles and has been in action since 1989. The same motor won three World Rally Championships Manufacturers titles in the mid-90s.

Sources, meanwhile, have claimed that US-specification 2.5-liter turbocharged boxer motor powering the WRX, known as the EJ25, will continue its service until the new WRX series is introduced next year. 

The EJ 20 powertrain was honed at various rough and tough rallies across the world. The boxer engine hauled Subaru cars through more than three decades of rally championships. It also powered several generations of mass production Subaru cars, gaining a legendary status over the years.  

More stringent fuel efficiency and emission regulations, however, called for a cleaner and greener engine. The Tokyo-headquartered company seems to have zeroed in the turbocharged FA24 boxer motor to run the upgraded WRX STI. The FA24 is the same motor that hauls the current version of the Subaru Ascent, the full-sized, three-row sports utility vehicle (SUV). The FA24, in the Ascent, outputs around 260 bhp. 

The retuned FA24 in the WRX STI will have reinforced crankshaft and pistons. That aside, the engine will have fine-tuned intake ports and valves and optimised timing balance. Among other modifications, the motor’s boost pressure will be tweaked and the braking capacity would be enhanced. The upgraded WRX STI will have a full time, symmetrical four-wheel-drive (4WD) system.

Reports also suggest that all new Subaru models may be underpinned by a Toyota-sourced platform. The two manufacturers have struck a deal to engineer 4WD cars together. The WRX could be one of these vehicles.

Also read: Subaru Forester GT: What to expect