Another S/C'd member worried about his AFR

[RagnaCaT]

Originally Posted by LtNoogie

I can't wait to see what a properly tuned Blitz'd Yaris can put out. I know we've been admonished not to put larger injectors on this car but hear me out on this theory.

What if the current fuel system with the Blitz piggyback fuel controller cannot pump enough fuel into the cylinders during WOT, leading to a lean condition. The ECU detects pre-ignition and has to retard timing to protect the engine, and as a consequence robs us of the maximum power the S/C can put out.

If I put slightly, not hugely, larger injectors in the car, it may run less lean during WOT and the ignition retard is less, giving more power. During idle or light throttle, the ECU detects a rich condition from the O2 sensor and is able to dial back the fuel to maintain proper AFR. Remember, I said slightly larger injectors, not fire hoses. If the increase in fuel is within the ECU's cabability to control, that could just work.

Anyhow, that's the theory I want to present to my dyno guy if I have him tune the car.

This is the smartest post, try OEM injectors from a 1.8 like corolla or XD could help you out??? i would go for it I swapped camry 2.0 3S-FE injectors on a corolla 1.6 4A-FE modded and got almost 2 hp at WOT and that was an N/A setup you are FI