can i swap my grey injectors with yellow in my 20tt without any mods being done?

[Guest vf20/21bg5]

:-\.....i have a 96 bg5 wagon with vf20/21 gtb turbo's,front mount,pod,no cats and big bore.....im wanting to get bigger injectors from my standard grey to yellow's.....i was wondering what type of yellow injectors and off what model i need to fit str8 in?......does the resistance of the injectors change much from model to model?...etc.....PLEASE HELP!..

[Guest]

the side feed yellow injectors will fit fine from sti upto ver 4 and gtb bd/bg.

But the car will run like a dog with them without some sort of ECU upgrade

[Guest vf20/21bg5]

oh thats good thanx....ive got a $300 chip by flipsystems in welly to help out with the timing advance etc but was also wondering if i upgraded my standard blue afm to an sti orange afm that would make a difference as well?????

[Guest]

The bigger AFM will max out at a higher power level.

I suspect the blue one will be big enough for your needs but i don't know there max power reading

[Guest vf20/21bg5]

ok cool so it wont really hurt to put one in then....just have to re-wire plug maybe.....cheers for your help

[nzkaosnz]

 Qwerty said:

But the car will run like a dog with them without some sort of ECU upgrade

^^^^

and new AFM may make it worse.

Normally, people get hold of a new (and matched) ecu, injectors, n afm

[Guest itsgotgo]

 vf20/21bg5 said:

ok cool so it wont really hurt to put one in then....just have to re-wire plug maybe.....cheers for your help

You will be forever killing plugs with overfueling,do it right once,never have to worry again

[kamineko]

these parts, injectors and air flow meters, are not just drop in upgrades.

they have their own specs - larger injectors need to be driven differently, and AFM's don't all output the same air/voltage curve

as qwerty said: if you want to run different injectors, have your ecu tuned to accomidate them. same with the AFM

or run a 'factory package' ie V3/4 yellow injectors, orange AFM and V3/V4 STI ecu as the ecu is already set for this combination.

your loom may or may not support a straight plug in of a different ecu (TT loom is different to WRX loom)

sorry, but your answer is no.

(some people have infact just replaced greys with yellows and claimed they work fine. I suspect they've never driven a subaru thats been running properly in the first place so wouldnt know the difference )

[Guest]

hey just had a look at my BG5 and im running yellow injectors and an orange AFM and mine seems to be fine i dont know what sort of ecu i have yet tho

[Guest boostcut]

that would be because you have ej20r motor, and gt dont...

[Guest]

bugger i was hoping to find a piggy back ecu stashed somewhere

[ReubenH]

GTB ECU's can be had for cheap, i gave mine away, or sold it for $20 or something silly.

To upgrade to yellows, you need the orange AFM, and the GTB ECU, and possibly a 3 bar map sensor. Aaaand at the end of the day, you'll still be held back by the EJ20H. You can only perform this upgrade if you have a 3-plug ECU car. That is, a LATE 96, that will be a BG5B, a BG5A will have an incompatible loom (4-plug). You also can't have an auto, if the car was ever an auto, it will also be uncompatible (one plug). Regardless, it IS possible to re-pin the plugs in the loom to run the 3-plug ECU. but there's more to it than that i suspect.

It's at times like this that i say.... why didn't you just buy a GTB/RSB?

[Durty-Sanchez]

Are you currently hitting fuel cut? I mapped your greytops to ~85% duty at peak, so there's a little room to move there. Ideally, if you did a split fuel rail conversion we could lower your A/F ratios which gives performance + more headroom from the inejctors (to prevent det). Yellow tops just give you more headroom with no performance increase

You *could* do what ReubenH suggests and just buy a gtb/rsb, but then you would have forked out the cash for a time bomb. Your EJ20H is a more reliable (albeit older and less powerful) engine. You don't need any of that other rubbish to run yellow tops, you just need me to get off my ass and install yellow tops on my legacy so I can test the fuel multiplier value to suit yellow tops, then reflash your chip..

[Guest vf20/21bg5]

hahah....time bomb no thanx but thank you guys soooo much for all your info ay....due to the amount of money ive already put into this gt to sort of basicly make it a gtb anyway i may-as-well carry on....you know how it is when money isnt too much of an issue and the pride of doing things yourself comes into play.....its called just being BLOODY STUPID! hahaha... nah im an ex trade cert mechanic of 9 yrs and building the last 10 ,but back 10yrs ago thy wernt really importing that many so i never got to work on many in my little workshop in hamilton... so im not very clued up as yet.....you may ask why now with a subaru...well because ive played around with every other engine/car type apart from a rotary and the subaru turbo's have torque,handling and sound i like so why not...plus thy are a challenge lol

...anyway over the next couple of months i will do what you guys have told me and have fun doing it...thanx again guys

[Guest vf20/21bg5]

...oh and yes im hitting fuel cut depending on air density and how far my foot is on the gas anywere around 4500-6000rpm....a bit early for my liking especially if redline is still a couple grand away......your mods will help im sure

[ReubenH]

It's all about the flow of the heads durty, I quite like having heads that are on par with V4 STi, and with V4 STi cams (if you didn't know, GTB cams = STI cams, and the only difference with the heads is the GTB ones have the extra stuff on the left head for the primary.)

Anyway VF20/21BG5, if you have an ECU mapped by Durty, he will surely be able to work his magic and get yellows in there fine. Yellows mean you can safely run more boost pretty much, you'll want to upgrade your fuel bump at the same time of course.. I'm currently running 18psi in my my car with a factory V3 STi ECU and yellows. It puts about 250-260HP to the wheels. It's a nice feeling, and not bad for essentially a stock longblock (the forgies have the same compression ratio as factory, the heads have not been worked at all)