Hi, it appears that changing the Intake Manifold Volume value from 4.38 to 4.5 made me have to increase FN035 values. Peak load was 96 vs 92. Has anyone experienced this?
What else does this setting alter?
I read a post where it was said to be a global multiplier and recommended to leave this stock or always use a value of 4. What is the most recent recommendation?
Intake Manifold Volume
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Re: Intake Manifold Volume
nah thats unrelated
manifold volume is a global transient fuel modifier
you dial it in to get tip in situated
manifold volume is a global transient fuel modifier
you dial it in to get tip in situated
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Re: Intake Manifold Volume
Thanks. So just give it the manifold volume it likes on tip in? Not sure yet why the peak load at all RPM changed. Other than manifold volume, I was playing with injector timing in a reasonable range, but large swings. 4.38 manifold volume revs like a champ with this engine.
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'19 F-150 3.3L
Re: Intake Manifold Volume
yep
nah that wont do it either
odd indeed
nah that wont do it either
odd indeed
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Re: Intake Manifold Volume
I find the peak load values seem to change with weather. I found if I dial FN035 in at home on a cool spring day, I have to adjust it again in warmer weather.
I've had a larger difference than what you're seeing just from weather conditions.
I've had a larger difference than what you're seeing just from weather conditions.
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Re: Intake Manifold Volume
Looking more into a few iterations of my tune with the difference tool, I did make a small change in the top of the MAF transfer curve along with the other things mentioned above.
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- Posts: 26
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- Vehicle Information: 1995 Mustang GT, CBAZA, 11:1 306, Ported Windsor Sr. aluminum heads 2.02/1.60, Trick Flow Track Heat, 24lb injectors, Comp cams 294/306 (2,800-7,000), Shorty headers, X-Pipe, Reverse Manual VB C4, 4100 stall converter, 4:10, MT ET Drag 26-10-15
Re: Intake Manifold Volume
In your case, the MAF changes were probably the cause.
The way I understand it... Load = Volumetric Efficiency
ECU calculates how much air the engine can pump and compares the expected value to actual flow the MAF is measuring. Change the MAF calibration and the calculated load is going to change.
The way I understand it... Load = Volumetric Efficiency
ECU calculates how much air the engine can pump and compares the expected value to actual flow the MAF is measuring. Change the MAF calibration and the calculated load is going to change.
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Re: Intake Manifold Volume
Thanks folks. The percentage change in MAF curve does correlate fairy close to the load shift in this case.