STi Big Turbo Install
Squeezing more power out of a turbocharged 2.5 liter flat four cylinder engine is as easy as swapping out the original turbo for a bigger one, right? If only it was that simple.
A good friend of the shop, and great customer, brought in his Subaru STi looking for some more boost. He picked up a rebuilt compressor (turbo unit) and wanted it installed, along with the requisite upsized fuel pump, injectors, intake hose, intercooler and blow off valve. Whenever you start replacing OEM components for larger capacity aftermarket bits, finesse and lots of patience are required. Today's engine bays are so chock full of equipment that it's always tough retro-fitting in new parts-- difficult but not impossible.
The turbo came from Forced Performance:
To get access to all the parts required us to take the intake and intercooler out.
Leaving what can only be described as a mess. The engine bay of a STi is one of the more confusing ones, with lines and tubes and hoses running crisscross. It's very important to keep track of every disconnect you make so that when it's time to put it all back together you don't run into an issue.
The components from Forced Performance were top quality, but we did have to grind, bend and plain old tweak much of the mounting hardware in order to make it all fit. The oil tubes and cooling lines around the compressor were particularly difficult to fit. This is where patience comes in, since we had to install, check, remove, tweak and re-install the turbo unit alone probably a dozen times. We could have settled for good enough and not taken the time to route everything perfectly, but that is not our style. Folks come in to our shop because they know we take the time and go the extra mile to make things right.
For example, here you can see where we had to grind some material away from a bracket in order to make the turbo fit properly.
I called the car's owner a "great customer" because he knew upfront that these jobs are difficult and require a good amount of time to make right. When it was all said and done, the project was a satisfying one for all those who worked on it. The car fired up on the first try, and ran well enough for the customer to take the car to the tuner to get the ECU reprogrammed to match the mechanical upgrades. So beware the next time you see an impeccably clean blue STi on the road-- there are a great many extra ponies under that scooped hood...