TC injectors and boost

[Tamago]

Originally Posted by cdydjded

Based on the experience of LTNoogie, Garm & ChinoCharles Iv come to the conclusion that that TC injectors are too big & the factory ECU can not control them. They all suffered from the same simptom, CEL, Rich Condition & high RPM misfires. I also know from experience that ECU's of most car today can only handle 10-20% larger injectors. Considering that the stock injector is +/- 190cc & the TC injector is +/- 380cc the problem is obvious. I feel that right now the best injector to use for boosted aplications with a factory ECU is the 1ZZ injector since LTNoogie has had positive results since he installed them.

obviously the stock ECU should not be used to control them.. are you trying to run a boosted engine on stock ECU alone?

injector scaling is imperative if you're using a piggyback controller anyway, hell, you could run 550cc injectors and a piggyback.

mathematically, at 10psi, WOT and redline, i was running the "tC" (2azfe people, camry, Rav4, Highlander, Corolla XRS, etc etc etc etc etc etc) injectors at around 70% duty cycle. that's pretty ideal actually. you also must consider that as the boost increases, your duty cycle must go down. why? because your fuel system is now fighting the natural compression PLUS the boost pressure in the combustion chamber. 10PSI of boost on top of natural compression, vs stock 50psi fuel system means your injectors need to stay open longer to inject enough fuel to achieve proper air/fuel.

so, in conclusion, the "tc" injector is NOT too big for the 1nzfe. in closed loop, the stock 1nzfe ECU has absolutely no problem maintaining 14.7:1 a/f without a piggyback. i know this because i drove my 1nzfe on 2AZFE injectors for 2 months sans-piggyback. open loop is a different story however.