If you are shopping for a turbo for your Subaru you may have come across the brand IHI Turbo. IHI Turbo is the OEM manufacturer for many automotive manufacturers including Nissan, Subaru, Mercedes and Ferrari. The Company is also a smaller subsidiary of IHI Corp., a large conglomerate involved in heavy industry and manufacturing. IHI’s long history spans over 150 years of manufacturing for aerospace, heavy equipment, marine, energy and aviation. IHI Turbos began making their way into Subarus in the EJ255 engine and with the release of the new Subaru STI 2015+ (VA) IHI continues to demonstrate new advancements in turbocharging with the VF48.
We are going to dig into why IHI Turbo’s VF48 (9F002) is a must have for any Subaru STI owner looking to upgrade.
VF48 (9F002) right out of the box offers Subaru owners an increase in flow rate of +10% which means that owners have recorded hp increases of 20-50hp with a simple handheld tuner like the Cobb Accessport. IHI Turbo along with a few other sources have also documented 400+whp outputs using the correct supporting mods and running E85. This makes the VF48 enticing to enthusiasts since it makes a great offering for high horsepower street cars.
One of the main reasons so many Subaru enthusiasts turn to IHI Turbo options is the price. The VF48 (9F002) is within the $1300 CAD price range ($1000USD for all our southern readers) making it an attractive offering given a lot of other aftermarket offerings start in the $1800 CAD price range. This means a better bang for buck for any enthusiast on a budget, however do not let the low price fool you, these units are also packed with some advanced technology.
The main reason this little turbo is so attractive to STI enthusiasts is mainly because of all the technology packed into the VF48. The 9F002 variation of the VF48 turbo is in fact the OEM turbo but it is also equipped with a forged billet compressor wheel with a larger exducer and inducer. The VF48 also sports a Teflon seal within the compressor housing which gets shaved down by the compressor wheel upon initial start-up. This provides a tighter tolerance and generates more efficient boost levels. The VF48 housing is also more resistant to compressor surge than its predecessors.
The IHI Turbo VF48 (9F002) is one of the simplest power adding modifications for the WRX STI because it is 100% bolt-on right out of the box, IHI also includes all the necessary gaskets to bolt the new unit on your EJ257. The VF48 (9F002) also has the same factory locations and fittings for the oil lines so your oil feed and return lines will reuse the OEM Subaru hardware. This takes a lot of the hassle out of completing the installation
Improved torque output at mid/high RPM range.
Quick spooling turbo.
Improved efficiency under boost due to compressor housing abrea-dable seal.
Capacity for power, the turbo can produce 400hp+ (supporting mods, E85, 18.5 psi).
100% Bolt-on installation.
Forge Billet compressor with larger wheel.
2004-2007 Subaru Impreza STI
2004-2007 Subaru Impreza WRX
2008-2014 Subaru Impreza WRX/STI
2015+ Subaru Impreza STI
In conclusion the IHI Turbo VF48 (9F002) is an ideal turbo for enthusiasts looking for a highly efficient bolt-on turbo that doesn’t require a ton of supporting mods to make power. This turbo reliably holds 400+whp with a few bolt-on mods and offers owners OEM reliability and top tier technology.
When looking for turbos enthusiasts should always have a power goal in mind, should that power goal be above 500+hp this turbo in OEM form may not fit your build envelope however there exists numerous types of hybrid VF48 options from brands like Pure Turbos that can easily achieve these goals. In OEM or upgraded form the VF48 (9F002) is the go-to turbo for Subaru owners looking for a fun streetable turbo option that provides more boost and better torque delivery from the stock EJ25 motor. It’s for this reason that we think the IHI Turbo VF48 is the best turbo for the Subaru STI (VA).