4.0l throttle body mass air and injectors

[allgravey20]

I have the sohc 4.0 and am going to try the 4.6l throttle body(65mm) do i need to change maf too? And what about injectors? I am not sure what throttle body, maf, or injectors my 4.0 has but i am a mustang guy and do have the parts at my disposal. Plus im a machinist which always helps. Was also going to port my plastic intake a bit for more flow. Any advice from people who have tried and were successful or unsuccessful would be appreciated. Also thinking about a 40hp shot of juice.

 

[2000StreetRod]

minimal improvements

I replaced my stock throttle body with a ported and polished 75 mm racing throttle body. I replaced my stock 55 mm MAF sensor with a LMAF 90 mm sensor. The performance improvements were minimal even with a custom tune. The stock 19 lb/hr injectors are adequate unless you make some significant changes such as forced induction, high flow heads, high performance cams, high compression pistons, etc. Changing to higher flow injectors without retuning the PCM will mess up the AFR ratios reducing drivability. Changing the MAF sensor will impact AFR ratios and load which affects spark advance. A new tune should be performed. Increasing the head flow will be accurately measured by the stock MAF sensor unless it gets "pegged" so a retune is not required.

Edit: Be advised that the upper intake manifold is rather thin. Be very careful when porting it.