What Injectors?

[Got Boost?]

Hi all,

I was wondering what kind of injectors i would need to suit my current setup, my current mods consist of:

BMC Airfilter with Heat Shield

NGK Iridium Plugs

FMIC

Turbosmart E-Boost

3" Exhaust with Dump Pipe and Hi-Flow Cat

Greddy Plenum

Bosch 040 (I think) Intank Pump

My turbo just died and i have purchased a new turbo, it is a RB25 turbo that has a new Ball Bearing T3/T4 Core good for up to 22psi. I know that with my stock injectors and computer i wont be able to run this turbo at its full potential. However i am buying a Power FC and i am buying injectors to.

My Question is, because i have the Greddy plenum i can get a GTR Fuel rail and run top feed injectors, would the 444cc injectors from a GTR be sufficient to run this turbo at full boost or would i need bigger injectors then these again? My aim is as much power as i can get from this current turbo and setup, all help is much appreciated, thanks

[benjiman74]

ive been told a good rule of thumb is look at what horsepower you would like to achieve then match them with the same figure injectors. eg 550 hp then get 550cc injectors etc

[Sydneykid]

Hi all,  

I was wondering what kind of injectors i would need to suit my current setup, my current mods consist of:

BMC Airfilter with Heat Shield

NGK Iridium Plugs

FMIC

Turbosmart E-Boost

3" Exhaust with Dump Pipe and Hi-Flow Cat

Greddy Plenum

Bosch 040 (I think) Intank Pump

My turbo just died and i have purchased a new turbo, it is a RB25 turbo that has a new Ball Bearing T3/T4 Core good for up to 22psi. I know that with my stock injectors and computer i wont be able to run this turbo at its full potential. However i am buying a Power FC and i am buying injectors to.

My Question is, because i have the Greddy plenum i can get a GTR Fuel rail and run top feed injectors, would the 444cc injectors from a GTR be sufficient to run this turbo at full boost or would i need bigger injectors then these again? My aim is as much power as i can get from this current turbo and setup, all help is much appreciated, thanks

What engine is this?

[rb25]

ive been told a good rule of thumb is look at what horsepower you would like to achieve then match them with the same figure injectors. eg 550 hp then get 550cc injectors etc

i was actually discussing this tonight with a friend and this is my theory:

If my 6cyl rb25 flows 550hp of air and need a total of 3300cc of injectors (6cyl x 550cc) will my 4cy sr20 which also flows 550hp of air need a total of 3300cc of injectors? yes. so that means it would need 4 x 825cc injectors (3300cc / 4cyl).

sustained air fuel ratios is what im keeping in mind. i think i am right in what i am saying :s im not too sure so correct me if im wrong

[Sydneykid]

i was actually discussing this tonight with a friend and this is my theory:

If my 6cyl rb25 flows 550hp of air and need a total of 3300cc of injectors (6cyl x 550cc) will my 4cy sr20 which also flows 550hp of air need a total of 3300cc of injectors? yes. so that means it would need 4 x 825cc injectors (3300cc / 4cyl).

sustained air fuel ratios is what im keeping in mind. i think i am right in what i am saying :s im not too sure so correct me if im wrong

You got it.

[Got Boost?]

oh sorry, its an RB25DET. Well at this stage i think anything over 300hp at wheels would be nice, i spose the best i can get above that is what im after, if the turbo does 22psi what kind of power will i be able to achieve with the injectors and power fc before the internals become at an unsafe point?

[Sydneykid]

oh sorry, its an RB25DET. Well at this stage i think anything over 300hp at wheels would be nice, i spose the best i can get above that is what im after, if the turbo does 22psi what kind of power will i be able to achieve with the injectors and power fc before the internals become at an unsafe point?

Firstly you need to remember that boost is simply a measure of restriction to airflow. It is airlfow itself that makes power, boost is really irrelevant. If you remove the restrictions in your engine, then you can make more power at lower boost. :idea:

Moving on to your question, 300 rwhp is ~225 rwkw and that is pretty much the limit of the standard injectors. RB25DET internals seem to handle ~300 rwkw (400rwhp) as long as the tuning is spot on. There are a number of threads on this subject, you really should do a search.

[Got Boost?]

oh ok, should have done that :Oops: but one more question, will the standard injectors and computer with that turbo get my 300rwhp?

[Sydneykid]

one more question, will the standard injectors and computer with that turbo get my 300rwhp?

With this information........

My turbo just died and i have purchased a new turbo, it is a RB25 turbo that has a new Ball Bearing T3/T4 Core good for up to 22psi.

you expect me to be able to tell if the turbo is good for 225 rwkw? :wassup:

Sorry I can't do that, there are at least 20 different combinations of T3 and T4 turbines & covers and compressors & covers. I have no idea which set the turbo builder has used. Since they have gone to the trouble (and expense) of doing a ball bearing hi flow then chances are it is a worthwhile upgrade. My best suggestion would be to find out who did the work and ask them, they should have a record via the turbo serial number.

[Guest INASNT]

For direct fit side feeds for the rb25 you can get 550,555 and 850cc, ranging from sard, hks and blitz.