Fi and forced intake.

[jason_]

Simple question. As it says, if ecm disregards o2 sensor on wot, how is fuel compensated as intake volume rises as suoer/turbo spools up to prevent lean burn? A rom to always obey o2 readings? Or fat injectors assumed on build?

If I missed the thread on search, delete this one and Pm a link.

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[bhazard]

That's what the VAF/MAF or MAP sensor is for...

[Advancedynamix]

VAF is topped out typically by 4k rpm at wot in most cars with this type of system. This is why people use bigger injectors, and rising rate fuel pressure regulators and retuned ecm maps to compensate for boost on cars with a vaf. You can also tune the vaf spring pressure to accommodate larger injectors. With enough fussing around and an accurate wide band O2 you can get things close, but you'll want to err on the rich side for safety and you'll almost never reach the output numbers that can be achieved with a closed loop/wide band system.

[getnpsi]

As a general rule you don't want to be in boost at part throttle anyway if you can help it. That goes for cars that are programmed oem with power adders, and for people who add them. You will have too much timing advance and part throttle knock even if the afr is OK. As said above the other sensors as a team know what is going on from the air coming in and the pressure. There are rom curves for those environments. Of course a regular NA computer isn't designed for boost, that is why we "tune." And for the cars that have output of 250hp and the owners want to be greedy to hit 300hp, going out of the limits of factory settings, they will do pretty much the same if huge aftermarket isnt available for that engine or ecu. ten years ago everyone still had to "tune." Now subaru ford dodge you name it all have inexpensive handheld programmers. Hasn't helped the amount of head gaskets piston holes and partouts on the forums thats always still operator error

[jason_]

Hm. Thats a bitch, we're still stuck at the mechanical and electronical limits in relation of displacement.

Room to improve on both?

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[getnpsi]

shh dont let mr dickmeyer hear that LOL. Well its true if you have uber limited funds still. I'd do some searches of his threads and see if what he offers for b3/b6 is something you'd want to give a go.If my b3 was tired id swap a b6 bottom end and let him at it on the top end as his orders are to order anyway.

[Zanzer]

MegaSquirt nthego:

[Festevil3]

MegaSquirt nthego:

x2