I have a 1994 WRX. Have seen plenty of second hand standard ECU's for sale, from STi Type R, WRX/Sti V3/V4. Will any go in mine?

 

the one to look for is the Z4 from a 95-96 wrx, this has trhe best map for your car.

forget about ecu's from later cars than 96 as they don't fit.

 

Wll a Z4 be a straight swap? I have a U8 which has been chipped? What difference will this Z4 make?

 

Depends who chipped the U8. But if it is chiped chances are it will be running more boost then a Z4.

If it came chipped from Japan then a Z4 will be alot safer.

 

Had it chipped over here from standard from a guy on here or SIDC (cant remember) It runs 14Psi. Did run 16Psi with chip but had to change exhaust and this reduced it

 

if it reduced due to the exhaust, you may be able to get it back up to 16psi by tightening the actuator by about 3 turn's. They can get a bit slack, as they are getting on a bit now.

Never heard of the exhaust reducing boost though, unless the up-pipe isn't sealed or cracked.

 

agree with scott here, you may have a problem adjusting the actuator on your car though as the TD05 changed from non adjustable actuator to adjustable in 94.

you may be lucky and have the adjustable one.

it sounds to me like you have the best ECU you can get before you start with a mappable one like a apexi/link/gems.

 

Can you buy new actuators for TD05s and how much do they cost?

 

How can I tell if my 94 WRX has an adjustable actuator?

 

Take the heatshield off the turbo.
The actuator rod will be held on to the turbo wastegate flap with a circlip.
If it's an adjustable actuator the rod will have a lock-nut and be threaded (you'll know it when you see it).

Undo the locknut before removing the circlip (it's a bit easier).

shorten rod = more boost
lengthen rod = less boost

In an ideal situation the actuator should require a small tug to slip it back onto the wastegate flap, NOT just fall on......