(NCP10/13) Air Flow Meter - Any option to increase size with standard ECU

[daewoo01]

Using the rough formula of needing 1mm/Hp/cylinder inlet pipe diameter for power, the standard AFM at 55.5mm (2ish inches) would max out at barely a couple of percent above standard.

e.g. 120Hp = 30Hp/Cylinder, requires the equivalent of 4 x 30mm Diameter inlet size.

to get to a modest 20% increase - 130Hp (through other mods) would require the AFM to be 65.5mm diameter to supply enough air. 10mm increase over the standard size.

Just increasing the inlet pipe size would make the AFM signal the ECU that it was receiving 45% less air that it really was, running ultra lean and boooom!!!

Is there a way to swap or modify the AFM so that the ECU supplies the correct amount of fuel for actual airflow as performance mods allow?

Maybe adding a resistor in the circuit, but I fear this would destroy idle.

I am looking to add a quad throttle body system, but continue to use the standard ECU. I understand sacrifices would be made.

[lani100]

No, the stock ecu cannot be fouled
Car won't run right with a bigger inlet pipe

ITB's on stock ecu ain't going to happen either.

[mitch9521]

Not happening with a Toyota ECU.

If you want to be able to mess with ECU tuning, invest in a good standalone or piggyback.

[speedworxs]

While it may be similar, on the mr2 groups they do what is called the MAF mod. On the 1zz (which uses almost the exact same system as the 1nz) they space the MAF a 1/4" higher to trick the engine to readjust ignition timing and fuel. That was on a slightly larger intake pipe, but I imagine you could experiment with it ... Ps, I'm not responsible