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Subaru Brings WRX S4 with Significant Power Upgrades to Tokyo Auto Salon; Will it See Production?

Subaru unveils the WRX S4 sports sedan at the Tokyo Auto Salon with extra power and other tweaks for performance fans. Will the extra power make it to a production model?

Every year, Subaru uses the Tokyo Auto Salon to bring out new models that have been tuned by Subaru Tecnica International, the brand’s motorsport partner. This year they brought four models, the Subaru WRX S4 STI Sport, Impreza STI Sport, BRZ STI Sport, and the Levorg STI Sport, all concept cars designed for the show. What does the WRX S4 tell us about STI’s future plans?

It’s what’s under the hood of the WRX S4 STI Sport that could get performance enthusiasts excited, if Subaru decides to bring it to production models. The WRX concept car looks like a factory car but it gets engine tweaks to bump up the power. The FA20 2.0-liter direct injection turbocharged (DIT) Boxer engine gets a significant bump in power over the standard mill. STI says it pumps out 221 kW (296 hp) and 400 Nm (295 lb. ft of torque), up from the 268hp and 258 lb. ft of torque in the US-spec engine.

Will the extra power make it to a production model?

We know the new-generation FA20 DIT engine is capable of more, because the Japan-only WRX STI S207 gets 328hp, so it’s not any stretch for the engine to develop more power. What performance fans are hoping is that Subaru will bring out a new WRX STI with the FA20 mill with more power and replace the aging 305hp EJ25 2.5-liter engine.

STI also gave the WRX S4 STI Sport other performance upgrades like dedicated tuning Bilstein front struts (DampMatic Ⅱ, inverted type) and STI coil springs. It also gets an STI performance muffler, drilled disk rotors, STI under spoiler (front side and rear), dry carbon rear lip spoiler, and a special bumper. Inside it features special leather seats (Bordeaux / carbon black), exclusive genuine leather steering wheel, and STI shift knob. But it’s what’s under the hood that has the most potential for the performance WRX/STI.

Subaru upgraded the fourth-generation WRX in 2015 with the new FA20 engine, but chose to keep the WRX STI’s old power plant. Fans want to see the STI get the new-generation DIT mill with more power like the WRX. The Subaru WRX S4 STI Sport Concept car at the Tokyo Auto Salon gets extra power and performance goodies from Subaru Tecnica International. Will Subaru give STI performance enthusiasts what they want in a production vehicle?

Photo credit: Subaru


Barney Stinson (not verified)    January 16, 2017 - 12:25AM

There's a big difference between putting out 328 hp from the venerable EJ207 than it is from the FA20. Have you seen the connecting rods on the FA motor? They're asymmetrical. While the EJ257 is aging, it's weak points are well known - piston walls milled down from the 2.0L, weak pistons, and unequal length headers leading to hot cylinder 4. The FA fixes the header to equal length. The cylinder walls are thick because it's a 2.0 bore. But now the compromise is the connecting rod. Unless they fix this, we won't get much more than 300 hp reliably. And if it ain't reliable, Subaru won't bring it.

Christopher w rogers (not verified)    January 16, 2017 - 3:35PM

The FA20 is an outdated motor already. Why the big push for that garbage? Subaru needs to take a chance for once and utilize a freevalve boxer with a dual housing turbo. Better performance, better tuning, better weight reduction, and better center of gravity. I mean to hold an FA20 as be all is primitive. Direct injection is worse for the motor in the long run. I have the EJ255 and it's nice and love the rumble but do some research. To keep emissions and all with more performance then research the freevalve. Why has von koenigsegg invested in it so heavily? Cause it's the future and it works.