CTR FlashPro tuning - fuel pump

FK2 Civic Type R 2015-2017 and FK8 Civic Type R 2017-2018
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Hondata
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CTR FlashPro tuning - fuel pump

Post by Hondata » Thu Apr 05, 2018 9:58 am

The high pressure fuel pump is a fixed volume pump driven from the camshaft. The high pressure pump output pressure is high (200 bar / 20 MPa / 2900 psi), and the inlet pressure from the in-tank pump is around 7 bar.

The pump can only pump a certain volume of fuel each camshaft revolution, which is almost exactly 1cc or 0.25cc per cylinder cycle. Since the fuel pump delivery volume per cylinder is fixed then the fuel pump delivery characteristic is tired to torque rather than power. From stock the pump is fairly close to its limit.
dyno-fuelp2.png
dyno-fuelp2.png (24.76 KiB) Viewed 2505 times
Here the datalog from a dyno run. In the bottom half of the image the purple line is the fuel pressure, green line is the target fuel pressure and the red line is the fuel pump duty cycle.

The fuel pump duty cycle is an important number to watch on the dyno. This channel did not exist and we added it in to the ECU to help everyone tune these engines. The duty cycle runs from 0% to 100%, with 100% being maximum output.

In the above datalog the fuel pump peaks at 95% at turbo spool and then tapers off to around 85% at peak power. This is fairly typical of a non-stock calibration.
dyno-fuelp1.png
dyno-fuelp1.png (25.21 KiB) Viewed 2505 times
Here is a datalog from a dyno run where the fuel pump is asked to deliver more fuel than it can provide. The fuel pump duty (red) is maxed out at 100%. The fuel pressure (green) drops. The ECU will tolerate a certain fuel press drop and compensate by increasing the injector duration without any ill effects, but at a certain difference (about 30 bar drop) the ECU will run a backup strategy. This increases the injection window to all the intake and compression stroke, which tends to make black smoke, an error code is set and the boost is reduced. Obviously we want to avoid this.

If, when you are tuning, you want to reduce the demand on the fuel pump, you can do one of three things:
1. Reduce the torque demand in the throttle tables.
2. Make the lambda leaner by using the minimum lambda table.
3. Reduce the torque/boost/air charge using the maximum air charge table. This is the best method.

In the above example I would reduce the maximum air charge in the region where the fuel pump is 100% by around 5% and then re-test. This is an interactive process.

What should the target fuel pump duty be? Because we are working with the air charge, not boost, it is largely invariant with temperature etc. I'm comfortable with peak duty cycles being around 95%. If the duty touches 100% very briefly then it is not necessarily anything to get too concerned with as long as the fuel pressure does not drop.
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Re: CTR FlashPro tuning - fuel pump

Post by FK8_K20c1 » Sat May 11, 2019 4:13 pm

I have a question regarding the fuel pump default settings. Im running the 93oct tune with dp, ic and improv throttle, If I enable the default fuel pump settings what impact will it do on the tune? I honestly have not datalog to see if my f pump is maxed or not but lets say its not max out what impact will the fuel pump settings do? Do you recommend the use of those settings for everyone or just for flex fuel people?

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Re: CTR FlashPro tuning - fuel pump

Post by Hondata » Sat May 11, 2019 5:04 pm

What default fuel pump settings?
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Re: CTR FlashPro tuning - fuel pump

Post by FK8_K20c1 » Sat May 11, 2019 9:52 pm

88% for the fuel pump target
88% for the hysteresis

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Re: CTR FlashPro tuning - fuel pump

Post by FK8_K20c1 » Sun May 12, 2019 8:57 am

Hondata wrote:
Sat May 11, 2019 5:04 pm
What default fuel pump settings?
Im talking about the latest flashpro update that enabled the fuel pump default settings.

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Re: CTR FlashPro tuning - fuel pump

Post by Hondata » Sun May 12, 2019 12:25 pm

Do you mean the duty limit?
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Re: CTR FlashPro tuning - fuel pump

Post by FK8_K20c1 » Sun May 12, 2019 3:43 pm

Hondata wrote:
Sun May 12, 2019 12:25 pm
Do you mean the duty limit?
Yes I have attached a screenshot.
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Re: CTR FlashPro tuning - fuel pump

Post by Hondata » Mon May 13, 2019 7:25 am

I would datalog the fuel pump duty first and see if the fuel pressure is dropping.
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Re: CTR FlashPro tuning - fuel pump

Post by FK8_K20c1 » Mon May 13, 2019 1:00 pm

I just dataloged a 4th gear pull and noticed a fuel pressure drop
but I had the fuel pump default settings enabled. Once again im kinda new to this tune scene and dont know if its normal or not. Attached is the log
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4th gear pull.fpdl
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Re: CTR FlashPro tuning - fuel pump

Post by Hondata » Mon May 13, 2019 1:03 pm

From that datalog you don't need the duty limit - it is making the air charge choppy.
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Re: CTR FlashPro tuning - fuel pump

Post by FK8_K20c1 » Mon May 13, 2019 1:11 pm

Correction fuel duty drop.

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Re: CTR FlashPro tuning - fuel pump

Post by FK8_K20c1 » Mon May 13, 2019 2:47 pm

Hondata wrote:
Mon May 13, 2019 1:03 pm
From that datalog you don't need the duty limit - it is making the air charge choppy.
Thank you. I reverted the values and did another log. Aircharge was different but there is no drop and fuel pump duty. FPD never hit 100%
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datalog0003.fpdl
(81.15 KiB) Not downloaded yet

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Re: CTR FlashPro tuning - fuel pump

Post by nolovez7 » Sat May 18, 2019 4:45 pm

Hey just installed Sirimoto flex fuel kit. Having some issues I believe with fuel. Have mishimoto intake, k tuned down pipe, car seems to hit what feels like a cut. 6k it acts like a redline, pump hits 100% duty after a Datalog review. Please help

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