DIY: 08+ STI intercooler on 04-08 Forester XT necessary and helpful mods! It fits!.... Kinda!
After you have removed the 04-08 Forester XT tmic you may have noticed just how much frustration it takes to place it back on the car. Some tricks are warming up the plastic inlet with a mini torch or soaking it in warm water to help it expand, allowing for it to slide over the td04 flange. Well, there are not many people I know that have that kind of time or patience.
With that being said I decided early on I would be swapping to a different top mount for that very reason. After searching for awhile for a cheap 04-07 STi Tmic I was left staring at a 08+ Sti version for $100 cheaper. I knew the fitment was tight but at the time I was trying to keep prices down and thought I could handle the issues that came along.
If you have followed my Tmic removal DIY and now you find yourself staring at an empty space on top of your engine with thoughts of how exactly you will sneak this sucker in. And what will you need to “massage” out of the way to help it find its new home.
Tools necessary for this job would be your mighty but gentle arm strength! A cutting utensil and a few old rubber hoses, radiator hoses being the best but you can make any breather sized hose work.
Now the first mod issue you will find is that the Ac line located near the firewall on both sides of the car, it sticks out a bit too far. Give them a bit of coaxing to move further towards the firewall. This will help gain a bit of space for the tmic. This space helps out but to finish it off you will now take your rubber hoses trim them to the length of the A/c line and split them lengthwise. You will now take your zip ties out and use them to adhere them to the ac lines. Rubbing between the lines and intercooler will now be buffered by the hose.
Now you will notice the fact that the stock Fxt intercooler support mounts no longer lines up with the holes. If you like you can buy the 08+ STi bracket that will fix this issue, otherwise you can make an extension yourself. I used a piece of scrap metal a friend had lying around, it was around three inches long and a half inch wide. Start by drill a hole in one of the metal, bolting it up to the stock bracket. With this setup, place the intercooler into the driver’s side bracket and you can mark your metal extension. Drilling a final hole will now allow you to fit it with little difficultly.
The last area of rubbing is the passenger lower corner of the tmic and the upper coolant reservoir hose to turbo. Taking another hose and trimming it to fit over the coolant hose helping it keep the coolant on the inside and not the outside. Now you can zip tie the rubber hose to connect the two together.
If you have an 04-05 Forester Xt you will need to upgrade your BPV and recirculation hose a 04-07 STI version. The 04-05 Fxt Bpv has a different bolt pattern and will not fit your new STi tmic. These are fairly easy to find online used and your new intercooler might even come with one.
If your tmic didn’t include the metal pcv connections that run along the front of the intercooler you will need to either add longer breather hoses replace the older hoses and metal unit. I choose to replace this with the stock unit because I like the factory look on the intercooler and didn’t want stray hoses laying across the throttle body…
Another slight issue that I found with my setup was the tmic 90 degree hose doesn’t fully engage the turbo outlet. There are many companies out there to purchase these from but I went with Grimmspeed. Their 90 degree hose is long enough to be cut to fit for your various turbos and intercooler choices.
Lastly the stock hood scoop splitter is quite undersized for the 08+ Sti intercooler. You can take your stock unit and modify it to fit the 08+ Tmic, which I am looking forward to attempting in the near future. But for now I use the Grimmspeed splitter for 04-07 STi fitted to 04-08 Fxts. The height is spot on and fits excellently with my 08 tmic but it doesn’t feed the entire width of the intercooler.