Injectors

[Cerby]

Hey everybody
I'm in the process of building a slightly less granny spec smallport for my rolla.
The pertinent specs for this question are:
ST Quad Throttle bodies
Larger cams(looking at around 264 or 272)
Adaptronic ecu

When i bought the quad throttle bodies they actually arrived with injectors, plugs, sensors, fuel rail heaps of stuff
Now I'm not going to going silly with this motor as in it won't be really hard tuned.
So the point is i am wondering whether i should be looking at upgrading the injectors?
I don't know how close the smallport 235cc injectors will come close to 100% duty so i don't know whether it would be a good idea to swap them for the 295cc injectors that came with the itbs?
I also don't know whether they are swappable lol?
So what do you knowledgable fellas think?
Cheers
Cerby

[Pitty]

i would go 13b rx7 injectors i heard there the best to upgrade to

[slide86]

well...what head are you using?

cause i think that 20v injectors are side heed and other 4age's are top feed....so they arent interchangable.

keeping this engine atmo, i cant see the need to put big injectors in it. the only thing you might want to do is put an adjustable pressure reg on it. then you can raise the static pressure abit.

this will give you more fuel across the range, with the same injectors. going to a bigger injector will cause some rough idle issues and over fueling, specially as its atmo and you arent going with really aggresive cams.

13B injectors are way over kill and not necessary for this application.......turbo motor maybe, but not atmo

[Cerby]

awesome thats what i needed to know!! Cheers

[Chrisso]

Cerby,

Slightly off track, but can you please post up a pick of how you've got your injectors set up in relation to ITBs and adapter plate? I had a look at my collection of bits last night and am a bit lost!

Thanks,
Chris

[Cerby]

oh i haven't actually done it yet just buying parts and planning out what i need to do so i can do it in one big go without stuffing up lol.
Chase down mattyshops build and tech articles on this site and on twincam (i think he's es9x or something on that forum)
He has picks of his quads in his sprinter that are very good and his tech article is a step by step on how to do it!

[Chrisso]

Thanks Cerby,

I've read his article, and can't seem to get hold of him, but I've resolved the issue. I had a look at the head this morning and it appears that the injectors actually sit above the manifold, directly into the head. This will mean all my issues are solved. Now it's just a trip to the machine shop to get the head work done so I can put it all together.

Chris.

[Cerby]

i've got a couple of pics of a good quad setup (actaully set as my background)
Chuck us an email addy and i'll email them to you