Okay, here we go. I have a 90 tII with an fcd, n1 catback, RB 3in downpipe( not yet installed), air intake, profec b, turbo timer, & autometer boost guage. I have changed my boost to 8.5 psi low setting, 10 psi hi setting with my profec b. I am still running my stock fuel system ( stock pump, 550cc injectors, stock ECU). Can I increase my boost if I put in a high flow fuel pump? Will just putting in the pump increase my fuel enough to where I won't blow my motor? If not what injector size do you recomend? I was thinking 720cc secondaries. Also I was thinking I might use the S-AFC by Apexi. Any help is really appreciated. Thanks. https://www.nopistons.com/forums/pub...IR#>/smile.png

720's and a better fuel pump should be ok for 12 PSI, but a good FMIC would be nice.

you have a couple of options. my car with a retuned ecu was running 11-13 psi in high gears and didn't lean out. running stock fuel system. if you want bigger injectors might want to go with bigger than 720cc https://www.nopistons.com/forums/pub...IR#>/smile.png

Well I would like the bigger injectors, but I don't want to go much bigger than 720cc b/c my car is a daily driver. Who tuned your ECU and what did they do to it? Did it increase the duty cycle on your stock 550cc's to keep them from going lean top end or what?

i bought a panspeed light sport tuned ecu from japan.....