Boosted legacy
I know it’s stupid enough to boost an n/a subie but
hey, gotta make it work somehow. So I have an 09
Legacy 2.5i se boosted by AVO. Should I leave it as
is, make the engine handle more/higher
compression, swap for an EJ255, or build the
engine or what do you guys think?
4 Answers
I would leave it alone. Trying to get more power will probably blow it up.
enginecreator answered 7 years ago
If it is boosted now and no power, maybe its blown up already or the computer tune is no good. Oh yea, have fun with that one, Diagnoses: Empty pockets.
With a blower you can increase blower boost with a smaller pulley/gear drive at the blower or larger at the motor. It will spin faster. Top grade gas is needed to avoid detonation. Sounds like pop corn or a rattle. Very bad, distroys pistons, rings and valves quickly. Most new computers have a detonation sensor and will pull timing or reduce rpms. Try hotter plugs and mixing some race gas with highest pump octane available. To increase compression you shave heads or increase piston height. Do not do this with a blower. Increased compression increases chances of detonation. So will increased boost but most motors built for boost have a dished piston for less compression on or off of boost.
You should check compression first and if all cylinders within 5 - 10 % of each other you can add horsepower. Check regular if pushing limits and detune or put new rings if more that 10% difference. camaro supercar coilovers are for sale.