Rods are every important in every motor, they take all the abuse an engine can
dish out. If you plan to pump out over 400HP in a Subaru motor racing rods are a must
to be reliable.
The rod with the wrist pin is the stock 2.5L Subaru cast rod, which is a typical
for an OEM rod.
The middle rod is the forge racing rod we offer specifically for the DOHC 2.5L motor (1998
and earlier). The top race rod is the forged rod we recommend on SOHC 2.5L motors (1999
It's important to note there are two different 2.5L motors from Subaru, both
are great for sandrail applications. Both use almost identical blocks, but
there are major differences in the heads and crankshaft. The 1999 and
later SOHC motors have 4mm larger rod journals than the earlier 1998 and earlier
DOHC motors. The heads on the 1998 and earlier have slightly larger ports
and two cams per head to push all 8 valves directly, not rocker arms. The
1999 and later SOHC motors use roller rocker arms to push all 8 valves per head.
At C&G we offer rods to build either type of the 2.5L Subaru motors (SOHC
or DOHC) to
400HP. But if you haven't chosen between the SOHC and the DOHC version and
plan to eventually build a full tilt wahzoo motor, we recommend starting with
the DOHC motor to get the larger intake ports. Although the DOHC is the
older style, they have slightly bigger intake ports to get more flow, producing
more horsepower. If you like the simplicity of the SOHC type it's a very
good motor with larger rod journals.
rods in your motor can be a limiting factor for reliability. If you want
to build a motor with more than 300HP installing aftermarket racing rods will be
needed. Then you can turn up
the boost on your turbo. Increasing the boost can be very exciting if you have the rods to handle the
Generally speaking stock rods can be used in Subaru motors with the turbo
boost set a 10lbs or below. 10lbs of boost on a 2.5L Subaru motor will
produce about 300HP. But if you plan to go beyond 300HP with a higher
boost level race rods must be used to be reliable.