So my understanding is this is inferred from the MAF. My issue is that it seems to be way off. Today it was reading 17.8 psi(I?m at 700ft elevation), so that can?t be correct. That was on my 2015 coyote with a whipple, and whipple tune with only adjustments to the tune being returless fuel system. Can anyone verify this or know it to be different then I understand?
I'd also love to know how this value is derived. I limited my max and min to way more acceptable values from the stock ones and it definitely helped.
I have noticed something weird. My whipple tune says 17.8psi, my Roush tune says 12.9psi, and I have a factory stock FPGM05H tune that reads 14.6 psi. This reading doesn’t seem to be effected by changing default baro and 17.8 psi is well out of the learning of baro pressure. It seems to have some effect on the tune as my MAF transfer between the 3 tunes seem to not work out to the same. Also my calculated MAP is the closest to actual MAP on the stock tune, not a surprise if this is used to measure airflow. Again this seems to leave me searching for variables that aren’t easily found. I think I’m going to message support and see if it’s a transfer function that can be added to the editor. I will update this as I find out more. Until then if anyone has an understanding of this or a better direction to find a solution I’m all ears.
Isn't baro calculated from ideal gas law? Mass of air entering the engine, intake air temperature, ambient temperature, throttle position, engine displacement, and engine speed?
Interesting though as it makes you wonder if you could use inferred baro to see if your tune is off. Tuning aside I know dirty air filters and MAF problem usually cause inferred baro reading to be off. (Too low if I remember correctly.) I'm going to look at old logs later tonight to check as I seem to remember lwfmaf and speed denisty tables on old 3V's being off causing inferred baro to look funny. I could be wrong though as I really didn't pay close enough attention.
You have me curious now lol
Baro FPGM05H.JPGBaro Old.JPGBarometric.JPG
These are all different tunes in the same area. 2 are from the past week and one is from an older log. All the same car with the same parts.
My stock strat defaults to 13.2 and my old logs show that. The Roush strat I use now defaults to 14.4 and my logs show that. There are logs showing that Baro has learned as well but never exceeds 14.x psi which is correct from my elevation.Originally Posted by Relentless
Deriving Baro from MAF, air temp, etc. in relation to Engine rpm, throttle, etc. makes sense. If your reading is super high in 17s I would think MAF was off... though I cant say Im surprised with a whipple tune lol . I wonder if boost can affect the calculation. Like when does it make the Baro calculation?
Knock Retard is the reduction or prevention of knock by lowering ignition timing:
(+) Adding Knock Retard = Reducing Timing. PCM is seeing knock.
(--) Lowering Knock Retard = Increasing Timing. PCM isn't seeing knock.
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2014 Mustang GT Premium. VMP Gen2R Supercharged with an FTI 3000rpm Converter. JLT, BMR, Steeda, Viking, etc.
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My whipple cal has a sensor, but I had to fix it because the dipshits at Beachmont ford placed the baro sensor in the SC manifold. Does your car not have a sensor wired to the airbox location?
i'm a newb, but what readings do you get if you just turn on the key without starting and read the level?
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