When your average enthusiast with a few bucks to throw around gets a hold of a Subaru they can really make some jam easily. But when you are an enthusiast and have the backing of major aftermarket player such as GReddy Performance, the possibilities are well endless. More than three decades of high performance know-how and products galore were at the disposal of this project and the results are impressive. GReddy always debuts highly anticipated shop cars and when we heard there was a new STi on their stable, we wanted to see where the renowned Japanese tuner had taken the 5-door.
With a few tweaks to the e-Manage to deal with all the new air and the addition of the GReddy v-Manage variable cam timer, an estimated 420whp was extracted.
The GRB chassis STi has received a bit of a polarized response in the Subaru community. Sure, it’s created for families in 5-door trim, but why is the new STi only available in wagon form? Regardless, the buying public has warmed up to it and any new STi you see on the streets usually has some degree of modifications done to it. It is not uncommon to see new STis rolling around with new wheels, aero parts and almost always an upgraded exhaust and intake. GReddy was banking on the GRB becoming a success and got to work on the JDM model, long before we even saw press vehicles here in North America.
At the core of the project is GReddy’s TD06 20G turbo. The upgrade kit replaced the tiny IHI unit the car is shipped with and includes an SUS manifold to bolt up to. Air is hauled to it via a GReddy Airinx intake and post-combustion is chilled with a GReddy Spec-R front mount intercooler kit. On the hot-side, gases head down into the GReddy Spectrum Elite exhaust for that sweet 50-state legal note. GReddy also added their outstanding 10-row oil cooler kit to keep the STi lapping and an oil breather to keep oil out of the combustion chamber.
When it came to tuning, GReddy relied on its own ECU, the e-Manage. With a few tweaks to the e-Manage to deal with all the new air and the addition of the GReddy v-Manage variable cam timer, an estimated 420whp was extracted. The new found power needed an ACT HCSS clutch and a matching lightweight aluminum flywheel to get the power down.
Read on for Full Specs