2017bluetruck

Never noticed it reading fuel air ratio's in stock tune on my 2017. Mine runs between 14 to 10.5 AFR at high boost and load. I may be misinterpreting the logs I have run. Any more specific's?
KM

KevinU

My tuner said 21.5lbs max after 5 stars 93 perf tune. 2018 f150 3.5l EB

w00t692

No no, after you tune you can get some more injector and and fuel pump out of them with some tweaking, but i'm saying when stock it's riding that close to the injector limits. But it's disappointing being so fuel limited when stock.

2017bluetruck

" No no, after you tune you can get some more injector and and fuel pump out of them with some tweaking, but i'm saying when stock it's riding that close to the injector limits. But it's disappointing being so fuel limited when stock."

That graph is from stock and the log is prior to any tuning. Not a challenge to what you posted but a request for more clarification.
Under load and subsequent boost my AFR lowered from 12-1 to 10-1 in 3rd gear at WOT. That does not seem to be leaning or running out of fuel as I understand it. If limited it's by the boost called for far as I can tell. KM

engineermike

2017bluetruck

Kinda what I figured "pre 18 2.7's are super fuel flow limited" seemed an over description. They can supply plenty of fuel stock and even tuned and it's much more a combinations of limits set by the factory as you pointed out. And shown in the data log as the RPM's rise to max and the load/boost is fairly constant the AFR is actually getting richer.
The injectors and fuel delivery are not at their limits just controlled by other parameters.KM

w00t692

I think you're drastically overanalyzing what i'm saying.

The ECU will cut throttle when it hits "injector limit" and won't make more power.

It has literally nothing to do with you leaning out or anything else. It won't lean out unless you run out of actual fuel pump before you run out of injector.

I'm not faulting your tune, i'm not arguing about your tune, it's a general statement of fact, not meant to be anything but informative

2017bluetruck

"I'm not faulting your tune, i'm not arguing about your tune, it's a general statement of fact, not meant to be anything but informative"

Fully understood, w00t692, not being argumentative either. The terms "super fuel flow limited", "injector limit reached", confused me some, I understood that too literally.
Probably overdoing the graph thing, so I didn't, but adding pedal position and actual throttle opening lines really display's how the computer controls things. KM

w00t692

Yes, you want the computer to stay being able to control the throttle plate in relation to the throttle pedal too. It allows for more driveability, safer for the motor because it has the ability to pull power if it sees you're out of injector, you're over scheduled torque, etc etc.

There are tuners out there that kill the vehicles ability to control that. It's wrong imo.

chimmike

Boost numbers are meaningless without coupling the information of turbo size or blower size. 20psi on stock ecoboost turbos is 1000x different than 20psi on a pair of GT35R's.