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Old 08-14-2005, 04:25 AM   #1
Scooby Guru
Member#: 53558
Join Date: Jan 2004
Chapter/Region: NWIC
Location: Deadford, OR
2005 Baja Sport
Gray/Silver two tone

Default EJ25 compression ratio

I've got an EJ25 that I would like to FI.

Other than complete custom everything, is there a simple, easy way to lower the compression ratio on the engine? I'm aiming for 8.5-9.1.
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Old 08-14-2005, 04:58 AM   #2
RIP 10/12/83 to 02/10/08
Scooby Specialist
Member#: 83254
Join Date: Mar 2005
Chapter/Region: NWIC
Location: Roy, Washington
98 2.5 RS
04 WRX


Only way your gonna lower the compression THAT for is new pistons. Or else you'd need some REALLY REALLY thick head gaskets (not a smart idea there) Depending on what year that motor is, its either 9.7 or 10.0 compression.
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Old 08-14-2005, 05:37 AM   #3
Scooby Guru
Member#: 64673
Join Date: Jun 2004
Chapter/Region: NWIC
Location: portland
1990 Legacy wagon
goes 12.387 @ 116.5


Pull your pistons and mill out some of the piston head. Can't tell you how much, but it does work, and if you keep the PSI down to a reasonable level, it should/can work.
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