Alternators
 

Simple question

Are all EJ20 Alternators the same?

Mines showing signs of wanting to exit stage left.

liberty ones are 80A i believe

not the same. But its not difficult to make a modern WRX unit work on a Liberty. If your running a big sound install then a modern Gen 4 Liberty one would be best as they are good for around 120 amps IIRC.

I have a 1998 WRX motor guys :)

Dont run a big stereo at all, got over that shit years ago. Alpine head unit 2 sets of splits. Couple of Defi's to power also, so not alot really.

normal rex one should suffice, i have heard the turbo forry ones have a bit more juice but its much of a muchness. im using the GX one on my car

Im not fussed with amperage, more on fitment. Dont want to buy one that wont fit.

I have a 90 amp Forester alternator fitted to my car. It requires wiring change just on the plug that goes into alternator but other than that its a straight fit.

tj, no there not all the same
theres 2 wire type and 3 wire type alternators.
for your RS you require a 2 wire type (as found on the early (pre97 impreza/rs)

although i'm aware that you can modify a 3 wire type into fitting a 2 wire application and vice versa.

Ill confirm it when I open my engine bay up, but I think I may have a 3 wire one atm. I assume 3 wire means 3 plugs into the alernator itself?

3 wire means pull the green plug and count the pins :)