IHI has been making the factory equipped STI turbo for years now. The latest in this line is the VF48, and it is the most versatile, and best performing STI turbo so far.
But IHI decided to take this turbo, and see if they could improve its performance even beyond what Subaru required, and that is the VF48 high Flow, or VF48 HF.
What IHI did was to take the standard VF48 that they make, and build it with a newly designed billet compressor wheel. Their goal was to make a 100% bolt on replacement for the standard VF48, but offer about 10% better performance.
And that is exactly what they did.
This turbo can be installed on a completely stock STI, and it does not need any tuning to run properly or to deliver slightly better top end power. This was tested and verified by Harvey at The Boostcreep in Colorado.
But if you do decide to tune the car with this turbo, it will offer better performance than the standard VF48, and it is capable of making just over 300 whp on E85.
This performance in a turbo made by IHI, and at this price point makes it an ideal turbo for any STI owner that is looking for a new turbo that offers easy installation and better performance.
IHI part number is F56CAC-SP014B