I'm going to get some 440s for my 93wrx import. how hard are the to change and is it a case of just swoppin them over?

cheers

 

If these are a upgrade won't you need a remap and possibly a upgraded pump?

 

i already have a 255 fuel pump fitted an maybe a z4 ecu on way as cant map my ecu

 

I don't understand what your hoping to achieve then by changing the injectors?
Upgrading the injectors isn't a performance mod it's a supporting mod.
If the map on the Z4 isn't mapped for 440's then all you'll achieve is a rich running engine.

 

What mods have been done to the car?
If you're looking for more power then pick a remappable ecu (Apexi power FC is good Andy F uses it and he has the fastest Impreza in the country possibly the world).
Then you can up the injector size,better TMIC or FMIC because the Apexi can be tweaked with the new items whereas the z4 cannot

 

omly mods so far are full decat and s/s un equal lenght manifold. plus a 255 fuel pump

 

What power are you looking for?

 

300ish

 

like others have said to take advantage of bigger injectors you would need an ecu to take advantage of them.
To be honest even with a mappable ecu you wouldnt get a great gain from the 440cc over the 380cc, better going to the 550cc imo, but you would need an ecu that supports that injector size(mappable or piggyback)

 

Apexi power Fc (£750 including mapping)
550cc injectors (£350 approx)
A better tmic (from a later model impreza) or a fmic
and more importantly a brake upgrade as you know the 93 wrx brakes are **** (late model 4 pots about £250)
this will get you 300+bhp.

 

I recently changed my grey 380's for yellow 440's (which turn out to flow 500cc/min at standard fuel pressure). I used to hit around 95% max injector duty cycle, now it never goes over 83%. Just gives that extra margin of safety and as orbix pointed out, it's a supporting mod, not a power mod in itself. Save up for a Power FC I'd say. You can run this on your standard injectors, and then remap it when you get bigger ones.