Anyone know what differences if any there is between a WRX RA engine and an STI RA engine ?

 

dont know, but ive just bought a 95 wrx ra and it goes like a rocket in standard form. cant imagine what an sti ra goes like if its any different

 

I want to know if there are any technical differences as one thing I have found out is the wrx ra has 380cc injectors but the sti ra has 440cc injectors.

I know they both have closed deck blocks and 5th injectors but i'm not aware of any other differences.

 

What year of car are you talking about?

Version 1 & 2 cars all have 380cc injectors, the 440cc came in on the version 3 to 6.

 

Well that kind of answers my question really. I didn't know all Version 1 & 2 cars have 380cc injectors.

So the wrx ra and sti ra engines are the same then if they are both version 1 or 2 ?

 

I know all but version 1 sti`s are rated at between 275-280ps. Where as the RA is rated as the same power as the standard wrx of the same year.

 

i think the heads on the sti ra + the cams , would be diferent than the wrx ,, not 100% sure but

 

Might be some useful info here Eta Tauri Site Impreza Reference - Japanese Specification
It says that the STI RA's have a higher output engine but if you look the engine codes up they have the same output but have different numbers

 

Probably same engines but different ecu's

 

WRX RA has hydraulic heads and Cast dogbone pistons,the STi Vers 2 RA has top hat inner shims,better cams and forged dogbone pistons.

Mick

 

So if you had the 2 engines side by side,how would you tell which was the wrx or sti engine ?

 

cams and heads are different along with the lifters, ecu/map etc, there are alot of difference between the wrx and sti

 

Camshaft out and see what lifters it has - or pull a head and drop a piston out to see if it's forged or cast.
Crank and rods are the same on both engines.
No easy way to tell 100% apart from a partial strip.

Mick

 

The version 2 (not sure about v1)Wrx Ra has the same solid lifter set-up as the STi Ra has it not?
It has the same engine red line of 7500rpm, where as the Wrx (and STi) is 7000rpm due to it's hydraulic lifters.

 

Did all STI RA's have red top manifolds then or did some versions have the normal silver manifold ?

 

STi Vers 1 and 2's had Silver Manifolds from the factory.