I friend of mine has a used 18G for sale that was on his WRX. He grenaded his tranny and is now moving on to bigger and better things so I'm lookin' to nab myself a deal on an 18G. And yes, I know I'm gonna need supporting mods and that I can't just bolt it on and go.

Anywho, I was looking at it and externally it appears be in good shape. I don't have exact dimensions, but just from eyeballing it up, the thing looks like it will probably attach to my stock manifold without any problems. However, I can tell you right now that it most definately won't fit on my downpipe. This is just a shot in the dark, but I'm gonna guess that I need to pull the turbine exhaust outlet (is this the thing that everyone keeps calling the 02 housing?) off of my stock turbo and bolt it to the 18G in order for it to mate up with my downpipe. Will the stock exhaust outlet/02 housing (whatever the heck it's called) fit on an 18G. And are aftermarket ones like the Helix one on Gruppe-S.com worth investing in, even if I still run the stock turbo for the moment?

 

the 18g won't bolt up to your stock manifold, the stock turbine housing will also not work with it. You would need a generic garret turbine housing and garret manifold and a custom o2 housing.

 

Besides the stuff he said, our evo turbois twin scroll and spins in the opposite direction so it wouldn't work even if you got it all bolted in.....

 

I thought the 18G was a Mitsubishi turbo, so why does it need a garret manifold?
In any case, it's good to know that I can't make the 18G happen before I bought the thing.

 

my bad, 18g is a mitsu turbo, you would need some sort of adapter plate or a custom manifold that can take the bolt pattern from a 18g from a subaru.