Decapped injectors
 

I done a search for this and didnt find what I was looking for, so either its not here, or Im blind :p

Question is, Im trying to decide on to decap my injectors or buy 2nd hand STi injectors for my car (Ill be installing a VF43 turbo & TMIC upgraded of course) into a MY02 WRX

With the decaps, does that change the amount of fuel used while the car is cruising as opposed to how much putting the STi injectors would while cruising?

So, basically, would there be any fuel usage difference between decaps and STi injectors if they had the same mods done on the car? (tuned of course)

Im leaning towards decaps at the moment, unless someone has some tragic stories to tell (was going to get ASG to decap them)

decaps or standard injectors will use identicle amounts of fuel if tuned for.

all it means is you injector duty moves from 50% with 550cc injectors to 35% (thereabouts) with 816cc injectors...

Decaps flow at 816cc, the STi injectors flow at 550cc. So yes a decapped injector will probably use slightly more fuel.

When I first swapped over to decaps with the TD04 I still kept basically the same fuel efficiency (~500km per tank). But, of course when I flog the tits out of it on a track day, it uses more fuel.

Once the ECU has been tuned for the decaps, your cruise economy wont be changed. Might be better with a good tune. You just end up running lower duty cycles.

Thanks for the help :)

Out of interest mate (if you don't mind me asking) what's it worth to have your injectors decaped all up (Labour & parts)....

abouts $400 I believe

Less $ than that.

No, it won't change fuel economy - That's all in your tune.

Dont know if this is relevent but I will add anyway.I have some old side feeds from a EJ22 (red ones) and while messing about with this and that, I decided to pull apart the injector. I removed the plastic cap and underneath was a thin metal plate with 3 or 4 holes in it, I then grabbed my side cutters and literally peeled off the plate and was left with a single hole.
If this is what decapping is then $400.00 dollars is a bit much.

Lol, youll be left with useless injectors if you do that. Grind it off.

Decapping still leaves the same 3/4 holes in the injector AFAIK.

Edit: For reference:

[url]http://forums.nasioc.com/forums/showthread.php?t=478921[/url]

[url]http://www.perth-wrx.com/vb/showthread.php?t=12198&highlight=decap[/url]