I have a Cobb Accessport and installed one of their maps on my 2004 STi
and you can feel the difference.  They have maps for both WRX and STi
but not for "normal" vehicles as far as I know.  Check their web site
for details
Jim

Hi,
My idea on that after fooling around with that sort of things for
some time. When you take medicine, it always comes with side effect.
There is no such thing as perfect medicine. Likewise if you start on
something like this, there is no end to it. You always gains some and
lose some.

Subaru offers some performance parts for some their cars - but for
'significant' HP gains, one needs to look at the aftermarket 'tuner'
stuff. It may include such things as open source or custom mapping of
the ecu, larger pre and post turbo exhaust, larger turbo, higher flow
injectors and larger fuel pumps, etc. Then there are brake upgrades and
suspension upgrades too of course.

For a glimpse of some of these mods, spend some time reading at
www.nasioc.com .

Carl