1ZZ Injectors on NA Setup

[lilredrocket]

Well the 1zz TB is a half inch bigger than the 1nz one so it can let more air pass through it when opened the same ammount. If you can get more air comming across your MAF sensor it will tell you ECU to dump more fuel into each cyl. the more air/fuel mix you can get into your cyl the better to a certian point. If you can add more air/fuel mix at the same ratio (stoich) as stock (on a stock motor ie. no FI) the longer the mix will burn pushing your pistons further and with more force on the power stroke. When adding more air/fuel than your motor can burn on the power stroke (running rich) your wasting fuel and ruining your CAT and O2 sensors. When your motor is getting more air as above your ECU will try and richen up the air/fuel mix to try and keep the mix stoich if your injectors cannot put out enough fuel you start running lean making it hotter in your cyl. (and running into the chance of melting things) the ECU overrides your pedal signal and starts closing your butterfly returning the mix back to stoich making you lose potental power.

Did I confuss you yet.

So by putting the larger TB on and getting more air into the motor adding the extra length of the spacer making the intake "hold" a larger volume of air starts letting to much air into the cyl. and the stock 1nz inj. cannot put all the fuel the ECU is telling them to put in the cyl. you start runing lean. So by adding the larger 1zz inj. being able to add the extra fuel bring the mix back to (happy) stoich.