Alright, I've searched and kept getting mixed answers.
My set up will be J-spec 88' TII motor, Full 3" exhaust, Intake, Microtech, Upgraded pump, FMIC, Plan to run around 10psi

I've read that the stock 550cc injectors handle to around 300hp? If thats true, than i should be good with my setup correct?

Thanks

 

you will be pushing it with the stock ones. I would get bigger. they will be the weakest link. with bigger ones you could run 14-15psi.

 

They should but, It depends; have you done proper wastegate mods? If not then no. Ur gonna boost creep like crazy in higher gears. Be safe at least get the injectors cleaned and balanced if thier old, also rewire that new pump.

 

It is difficult to speculate because of several variables, such as your fuel pressure, volumetric efficiency, condition of your fuel injectors, etc. The best way to tell if you need larger injectors is to run the engine with what you have, and monitor your duty cycle and/or air-fuel ratio. You can upgrade to larger injectors any time.

As a quick answer to your second question, no, the stock 550 injectors at 80% duty cycle will not support 300hp with a stock S4 turbo screaming up to 10psig boost if you are running the stock fuel rail pressure. However, you aren't going to make 300hp at 10psig anyway.

 

i have 550cc all round and run 15/16 psi . check sig for current mods.
I have not had any issues for the past 5000 miles of really hard driving.

 

i also only push it to 15 when i am carefully watching and feeling the car otherwise i try and keep it around 9-12 psi

 

ummm...... good luck. only a matter of time.

I'd be interested to see a wide band graph of that.

 

The wastegate has been ported majorly, and all the injectors have been cleaned. I have another set of 680cc injectors which i was going to use as secondaries, or maybe sell them to help finsh my project (This motor is in a 1st gen rx7) But Im guessing i'll just use the 680's to be safe.
The fuel pump is an MSD inline, 43gph i believe at ~42PSI. and everything is going to be controlled by a Microtech LTX-8

 

how much will you sell the 550's for, I need some

 

I will have a pair of 550's in about 2 weeks after I get my rebuild done...im
slapin' in some 680's in their place
PM me if your interested

 

if you are going to have a microtech you might as well use larger secondaries to squeeze a little more hp out of it.

 

Not as much as to squeeze hp out of it, but to do so safely.