Mention the word EJ20 to Subaru enthusiasts and you’ll be met by more than a twinkle in their eyes. The turbocharged version of the 2.0 litre flat-four engine, which debuted in the Legacy in 1989, has been an inseparable part of Subaru’s history – it powered the iconic WRX STI rally refugee and helped the Pleiades brand secure numerous teams’ and drivers’ World Rally Championships in the 1990s and 2000s.

So revered was the engine that even after the WRX STI moved to the larger 2.5 litre EJ25 in export markets, the company persevered by keeping the EJ20 in its domestic market of Japan, continuing to finesse the mill to churn out ever higher power outputs over the years. But all good things come to an end, and the company is discontinuing the engine by the end of 2019.

To celebrate the life and times of the boxer, Subaru is introducing a runout special exclusive for the Japanese market, called the WRX STI EJ20 Final Edition. Set to be shown in prototype form at the upcoming Tokyo Motor Show (alongside the Levorg Prototype), it will be open for orders on October 23, with just 555 units – a nod to its main sponsor during its WRC heydays – to be offered for sale through a lottery method.

While details are light, the car will clearly come with a number of tasty commemorative goodies, including the trademark gold finish for the 19-inch BBS alloy wheels, pink highlights on the grille and vents aft of the rear wheels – the latter have been seen on numerous high-performance specials since the S207.

Subaru says the Final Edition will get a “balanced” version of the EJ20, which should mean it has the same uprated engine as the S208 and RA-R. In these models, it makes 329 PS at 7,200 rpm and 432 Nm of torque from 3,200 to 4,800 rpm. More details will be released when the car is revealed in full at the show.

Of course, the engine’s discontinuation only affects the Japanese market, and export markets will continue selling the current WRX STI – at least, until the next-generation model rolls along.