Like any family there are many hand me downs to be had for the younger siblings. This is how many of mods made it to my Forester from my Sti. Simple items like floor mats and gave way for a downpipe and Accessport, but what would be the next item from the showcase…?

How about a rebuilt VF39! Come on down… you are the next contestant of my Forester was my daily and is now becoming a project car!

Sti vf39 turbo… some assembly required. How to rebuild your Vf turbo!

The STi came with a damaged turbo stud when I purchased it and when removing the downpipe a few times for various project it had become further damaged to the point of being useless. Then came the day to finally remove the STi VF39 for a 15+ STi VF48 turbo and another nut decided to come off halfway, once halfway off it became one with the stud and stopped moving. A new removal tool came into play and the cutting came into play.

In order to “rebuild” the Sti VF39 a new center section and hot side was purchased! Once they arrived the rebuild began, with this many new parts everything is pretty straightforward and easy. A quick run down of this is removing the wastegate actuator and arm, followed by hotside clamp, unbolt the coldside housing and swap over you oil/coolant lines. Replacing If you are curious about detailed rebuild guide for your own turbo with a new center section, head to Rebuilding your VF turbo!

Next up was finding time for the install… After a couple weeks a block of time was alotted and on the turbo went. This is a great time to install an IAG braided oil feed line, the factory hard line is notorious for being a bear to reinstall on a new turbo. I didn’t do it this time, but rest assured on my next big project I replaced that factory hardline. If you are curious about that install, IAG braided oil feed line install guide is here for you!

Iag’s stainless braided turbo oil feed line.

Another necessary upgrade for our Vf39 turbo is a larger STi top mount intercooler. The plastic Forester Xt leaves a lot to be desired. Sure the plastic helps minimize heat retention, it sure doesn’t look pretty within the engine bay. I also strongly disliked the plastic coupler that connects the intercooler and turbo. Removing and reinstalling the top mount intercooler is usually a pain but this ups the ante in my opinion. This may have very well be the real reason I replaced the intercooler and turbo, that awful coupler.

Big old 08+Sti tmic! A little roughed up but the price was right.. Tips for after you install it in a Forester!

Everything on the install went according to plan, a new Cobb stage 3 tune was applied, we then started the vehicle back up and topped off the upper coolant tank. This would soon show that this was a mistake…. Taking it for a test drive showed the car boosting fine and everything working but the temperature decided to spike and stay overly hot. What was the issue!?

The issue was losing more coolant than I initially had thought and so a pocket of hot air had become stuck in the coolant system. So a late night double checking of everything else made this apparent. With the proper coolant funnel installed and the system filled and purged of air.. everything was back to normal.

Onward I drove late into the darkness of the night as another project had taken quite a bit more time than expected by trying to shortcut a necessary step. The next week i was met with a much smoother powerband thanks to the tune, turbo and intercooler. I did miss the off the line pop of the TD04 but the upper rpm power was a good trade off.

With more boost flowing and more intercooler cooling, where do we go from here on imminent destruction of civil daily driving…. What items would show up for cheap on the boards or eBay…? Stay tuned to find out what the next financial mistake for the Forester is! I am sure I will do some more foolish things!

Amazon part links!

Subaru super blue coolant

EPAuto spill proof coolant funnel

Nothing says daily driving to work quite like larger turbo and intercooler!

Related reading!

Amazon part links!