Reasons for loss of fuel consumption
06-20-2016, 06:42 AM
#1
Reasons for loss of fuel consumption Something that has me perplexed is why my engine seems to be burning less fuel (in lbs/hr) lately. Usually it burns around ~450 lbs/hr on ~12psi and close to 480-490 at higher boost levels. Yesterday I did a log and I'm only using 396 lbs at 14 psi. Seems like I'm missing a lot of power. Yesterday was hot (about 90*) vs the much cooler temps (around 50-60* ambient) that I did the previous logs so wondering if that has anything to do with it. Or, was also wondering if the "summer" blends of fuel have an impact. Otherwise, car runs really good and clean. This is a stock LQ9 with the LS6 cam, BR7ES's at .022. Timing 11*, IAT's around 100*, spraying a little 50/50 also. Next test will be to shut the 50/50 off to see if its drowning anything. Thanks!!
06-20-2016, 08:02 AM
#3
93 octane.
And I forgot to add which is probably the reason for less lbs/hr...
I upped the base fuel pressure from 43 to about 53 to see if I could get a better idle...which I actually did. So the DC is now a bit lower up top than before. I figure that total fuel consumption should still remain the same though right?? Maybe someone can explain what I'm missing here as far as how the system calculates fuel flow/consumption.
And I forgot to add which is probably the reason for less lbs/hr...
I upped the base fuel pressure from 43 to about 53 to see if I could get a better idle...which I actually did. So the DC is now a bit lower up top than before. I figure that total fuel consumption should still remain the same though right?? Maybe someone can explain what I'm missing here as far as how the system calculates fuel flow/consumption.
06-20-2016, 09:12 AM
#4
Yes that is the reason
For fuel consumption in the holley it does not watch and use actual fuel pressure for the computation. It only uses what you have entered into "actual system pressure"
Why the consumption number means fuckall unless the correct number is in there and you actual hold a perfect 1:1 rise on fuel pressure
Start dropping pressure with boost and it will give big time inflated numbers
For fuel consumption in the holley it does not watch and use actual fuel pressure for the computation. It only uses what you have entered into "actual system pressure"
Why the consumption number means fuckall unless the correct number is in there and you actual hold a perfect 1:1 rise on fuel pressure
Start dropping pressure with boost and it will give big time inflated numbers
06-20-2016, 09:17 AM
#5
air density from 50F to 90F is approx 10% lower
06-20-2016, 09:48 AM
#6
Yes that is the reason
For fuel consumption in the holley it does not watch and use actual fuel pressure for the computation. It only uses what you have entered into "actual system pressure"
Why the consumption number means fuckall unless the correct number is in there and you actual hold a perfect 1:1 rise on fuel pressure
Start dropping pressure with boost and it will give big time inflated numbers
For fuel consumption in the holley it does not watch and use actual fuel pressure for the computation. It only uses what you have entered into "actual system pressure"
Why the consumption number means fuckall unless the correct number is in there and you actual hold a perfect 1:1 rise on fuel pressure
Start dropping pressure with boost and it will give big time inflated numbers
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06-21-2016, 05:57 AM
#8
I have noticed on my data logs the max. fuel used is
diff (more) than where the overlay (Holley HP) shows it to be.
I am guessing the closed loop comp. adds the diff?
Interesting raising the base pressure and not changing it in the system, something I wouldn't have thought of, and the effect.
diff (more) than where the overlay (Holley HP) shows it to be.
I am guessing the closed loop comp. adds the diff?
Interesting raising the base pressure and not changing it in the system, something I wouldn't have thought of, and the effect.
06-21-2016, 06:45 AM
#9
I have noticed on my data logs the max. fuel used is
diff (more) than where the overlay (Holley HP) shows it to be.
I am guessing the closed loop comp. adds the diff?
Interesting raising the base pressure and not changing it in the system, something I wouldn't have thought of, and the effect.
diff (more) than where the overlay (Holley HP) shows it to be.
I am guessing the closed loop comp. adds the diff?
Interesting raising the base pressure and not changing it in the system, something I wouldn't have thought of, and the effect.
I was able to a achieve a slightly better idle going from a 43 psi to 53 psi. Not a nigh/day difference, but noticeable.