V5 STI injector recommendation

[brucestubbs]

Hey guys, 

 

Just looking for some recommendations for sizes and brands of injectors for my gf8 build. Really wanting them to fit stock location so I don't have to do a top feed conversion.

Shooting for around 220kw atw and would love to hear from some of you with similar builds. 

Cheers

[pl0x]

Factory subaru STI injectors (yellow side feeds) will do 220kw. Make sure you have a decent fuel pump and good voltage at the pump and they'll be fine.

[runrabbit]

FYI - I have yellows, and vf22 and only make 200kw. Injectors are at 95% duty and tuner doesn't recommend going any higher. Would love to find a another 20kw if possible.

 

 

[brucestubbs]

Okay just to clarify, I'm looking for injectors that will be able to safely go above and beyond my power goals, and have plenty of headroom for the future.

Cheers

[pl0x]

10 hours ago, runrabbit said:

FYI - I have yellows, and vf22 and only make 200kw. Injectors are at 95% duty and tuner doesn't recommend going any higher. Would love to find a another 20kw if possible.

 

 

Sounds like something is wrong. Whats your fuel pump and how is it wired?

Factory fuel pump and/or factory wiring won't cut it.

[pl0x]

5 hours ago, brucestubbs said:

Okay just to clarify, I'm looking for injectors that will be able to safely go above and beyond my power goals, and have plenty of headroom for the future.

Cheers

De cap your yellows

[RaKid]

Phase 2 injectors can be de-capped and have been proven to flow enough fuel for 260kw. They flow roughly 550cc when de-capped. Similar to what non de-capped pinks flow.

 

While you said you're not interested in a top-feed conversion, I have a alternative option which is a Rev D intake manifold, fuel lines, rails, pink injectors, and loom. It utilises the factory V5/6 throttle body and loom, so there's no re-wiring required. Simple bolt-on upgrade and then you'll have loads of injector head room.

[runrabbit]

12 hours ago, pl0x said:

Sounds like something is wrong. Whats your fuel pump and how is it wired?

Factory fuel pump and/or factory wiring won't cut it.

Walbro fuel pump replaced oem.

[brucestubbs]

13 hours ago, RaKid said:

Phase 2 injectors can be de-capped and have been proven to flow enough fuel for 260kw. They flow roughly 550cc when de-capped. Similar to what non de-capped pinks flow.

 

While you said you're not interested in a top-feed conversion, I have a alternative option which is a Rev D intake manifold, fuel lines, rails, pink injectors, and loom. It utilises the factory V5/6 throttle body and loom, so there's no re-wiring required. Simple bolt-on upgrade and then you'll have loads of injector head room.

You've got me intrigued. So the intake manifold, fuel lines, rails and loom from a legacy rev d? And that will plug straight into the v5/6? plus the pink injectors. Sounds interesting, any clue where I could find those around auckland easily, and how much they go for?

Cheers

[RaKid]

10 hours ago, brucestubbs said:

Any clue where I could find those around auckland easily, and how much they go for?

 

Yes, me. I have the complete kit for sale now on TradeMe here

[pl0x]

11 hours ago, runrabbit said:

Walbro fuel pump replaced oem.

What's the wiring? factory wiring has voltage drop before the pump.

A friend only made 200kw ish with Walbro on factory wiring, it was running out of fuel pump. With the wiring mod it made 230kw

[ginganinja]

Out of interest what is the wiring mod?

[pl0x]

6 minutes ago, ginganinja said:

Out of interest what is the wiring mod?

Basically that ^^. Pretty much a slightly larger power cable direct from the battery with a relay, Means the pump gets full voltage.

[Pappu1]

this rewire does make a difference actually..

did a pump hard wire on a B4 legacy and the injector DC dropped a fair bit with the same AFR in place...

 

[ginganinja]

Awesome. Thats good to know.so this is additional to the factory wiring?

 

Sorry im not much good with electrical stuff.

[pl0x]

1 hour ago, ginganinja said:

Awesome. Thats good to know.so this is additional to the factory wiring?

It generally uses the factory wiring as a relay switch (turns the direct power wire on/off)

[ginganinja]

Bit of a thread dredge here. Random question on the topic of Phase 2 Yellow injectors from V5-6 sti motors. Are these 440cc from factory or 550cc??

 

I have been hearing lately that they are actually 550cc. Tuner said I still had headroom in the fuel system on my stock Yellows at 226kw. 

 

[Loren]

35 minutes ago, ginganinja said:

Bit of a thread dredge here. Random question on the topic of Phase 2 Yellow injectors from V5-6 sti motors. Are these 440cc from factory or 550cc??

 

I have been hearing lately that they are actually 550cc. Tuner said I still had headroom in the fuel system on my stock Yellows at 226kw. 

 

 

550 in the v5/6 sti

[ginganinja]

36 minutes ago, Loren said:

 

550 in the v5/6 sti

Interesting, do you know if this is at 80% duty cycle or 100%? 

 

Or are all injector sizes measured at 100%

Edited December 4, 2020 by ginganinja

[Loren]

51 minutes ago, ginganinja said:

Interesting, do you know if this is at 80% duty cycle or 100%? 

 

Or are all injector sizes measured at 100%

 

I think the measure is when wide open. Supposedly the JDM STi runs a higher static pressure as well... 53psi vs 43psi for

the wrx or US spec cars. You can always get them cleaned and flow tested so you know exactly what you have.

[ginganinja]

On 4/12/2020 at 5:13 PM, Loren said:

 

I think the measure is when wide open. Supposedly the JDM STi runs a higher static pressure as well... 53psi vs 43psi for

the wrx or US spec cars. You can always get them cleaned and flow tested so you know exactly what you have.

Revival again. Got another project happening. So if this is the case that V5-6 yellows are 550cc does that mean the V7 pink top feeds are only 15cc more?  So basically the same size.

 

Or do the top feed injectors operate better overall giving better fueling?

[Loren]

9 hours ago, ginganinja said:

Revival again. Got another project happening. So if this is the case that V5-6 yellows are 550cc does that mean the V7 pink top feeds are only 15cc more?  So basically the same size.

 

Or do the top feed injectors operate better overall giving better fueling?

 

I know nothing about the v7 injectors. 

 

AFAIK top feed just gives you a lot more options and much greater maximum flow.