New to the WRX, just picked up base sedan..

[RayfieldsWRX]

I'm no transmission expert, so someone chime in if I'm disseminating bad info.

I'm pretty sure that, with some small changes for gear ratios and some more durable gears, the 5MT in the WRX is basically the same design dating back to 1990, and used in most all of the cars with EJ engines. (So originally intended to hold up against about 90 hp. ) It's been used in a number of different models.

[zax]

I was just wondering is the 5/speed in our cars just an off the shelf unit borrowed from the Pre-2012 Impreza line and the Outback, Legacy, Forester? or is the unit unique to the WRX? I know the 6-speed I'm the STI is a purposed built unit made specifically for that model of the WRX.

No, it is specific to the WRX. IIRC, the 2002 WRX transmission may have been similar to the unit in the Impreza RS, but starting in 2003, the WRX received unique gears that were borrowed from the 1990s Impreza WRX and STi:

Subaru Transmission Chart

I'm no transmission expert, so someone chime in if I'm disseminating bad info.

I'm pretty sure that, with some small changes for gear ratios and some more durable gears, the 5MT in the WRX is basically the same design dating back to 1990, and used in most all of the cars with EJ engines. (So originally intended to hold up against about 90 hp. ) It's been used in a number of different models.

The case and input/output shaft is the same miserable design that was used in the early Imprezas.

[RayfieldsWRX]

I knew Zach would know more.
Anecdotally people have always said that it's the same basic design since the early '90's. Good to get into the details.