I cant believe I am asking this. I know I have read this before but I searched for an hour and cant find it. I want to get bigger secondary, right now I have the purple ones part # 495500 1970 witch should be 550cc from what I read in the searches. Its just that on the side of the injector it says 630, so could it be a 630cc? Any way I am getting all 3in exhaust, fmic, and plan on running 15lbs at track and 10-12 around town. Now with the stock ecu what secondary fuel injector should I get. Like 720cc. I cant go that much bigger with stock ecu, right?i have a 88 jspec t2 motor with a 87t2 wiring harness. So I know I will have to change some stuff with the harness to use the 12-13ohm fuel injectors.

 

http://rotaryresurrection.com/injector.html

 

already read it. it dose not answer my question

 

You can put whatever size injector you like against the stock ECU. Its stupid and has no idea what your plugging into it. The problem is, that it will pulse the bigger injectors at the same rate. For your purposes, the 720s (680s) are probably fine in the secondary positions with stock mapping. Just be careful if you go bigger.

Also, depending on the year/model of your car, you may need to add a 10 ohm resistor inline with the fuel injector. Either at the plug or by the ECU. The best way to tell this is to check for a resistor pack. Its a big silver box UNDER the air cleaner box. If thats there, ,then your safe.

Jarrett

 

thanks that helps a lot. and i have the resistor pack....720's here i come