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Author Topic: MED9 HPFP & LPFP Control  (Read 193984 times)
S2evo1
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« Reply #60 on: July 22, 2014, 10:16:47 PM »

This would be awesome, ive had a quick look at the RS3 file but cant really find any differences but havent looked to hard yet.

You need to stop looking in the Engine ECU sw  Wink
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Claudietto81
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« Reply #61 on: November 02, 2014, 06:58:15 AM »

Hi guys I have a question for you
I was looking at these fuel rail maps: FWPHDR and FWIHDR. Can someone explain me how they work? There is the need to change them in a stage3? I have seen that, changing the values in these maps, the injection time changes in the logs.
Thanks to everybody
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hammersword
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« Reply #62 on: November 03, 2014, 05:13:33 PM »

the whole game on LPFP calibration is the DC map calibration axis. RS3/TTRS LPFP flows double more than BWA LPFP!
Let the ECU know that the car has installed a double size LPFP and don't just cut Duty Cycle

No need for TTRS/RS3 PWM, the BWA or BHZ is more than enough to control the big LPFP
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« Reply #63 on: November 03, 2014, 09:06:52 PM »

the whole game on LPFP calibration is the DC map calibration axis. RS3/TTRS LPFP flows double more than BWA LPFP!
Let the ECU know that the car has installed a double size LPFP and don't just cut Duty Cycle

No need for TTRS/RS3 PWM, the BWA or BHZ is more than enough to control the big LPFP

KFFLAF is the main map for this?
What about the maximum flow values (PEKP), are they required?
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Claudietto81
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« Reply #64 on: November 12, 2014, 10:48:43 AM »

Hy guys I wonder why when you log your LPFP at WOT the duty cycle you see by log doesn't match never the duty cycle in the dump. Basically it is all the time the maximum allowable duty cycle value, for istance 92%. If you look at fuel pressure in the log at wot at high rpms it will be around 3,5 or 4 bar. But for such fuel pressure doesn't correspond maximum duty cycle in KFFLAF but for istance 60%. It is normal this mismatching? in the meaning it is normal to see all the time maximum duty at WOT?
Thanks
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mec
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« Reply #65 on: November 12, 2014, 12:49:03 PM »

Hy guys I wonder why when you log your LPFP at WOT the duty cycle you see by log doesn't match never the duty cycle in the dump. Basically it is all the time the maximum allowable duty cycle value, for istance 92%. If you look at fuel pressure in the log at wot at high rpms it will be around 3,5 or 4 bar. But for such fuel pressure doesn't correspond maximum duty cycle in KFFLAF but for istance 60%. It is normal this mismatching? in the meaning it is normal to see all the time maximum duty at WOT?
Thanks


Sounds like your pump is on its way out, the controller is pushing higher DC to try to get it to meet demanded pressure, but its not able to so DC stays pegged at 92%
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Claudietto81
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« Reply #66 on: November 13, 2014, 04:38:06 AM »

It is strange because i have seen this behaviour on the most cars i logged. The last one a scirocco R with HPFP loba, 76 skat exhaust, and evoms intake. Duty cycle was 92% and fuel pressure around 4 or 4.5 bar something like that. I'd like to understand if it is normal such behaviour or not.
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eliotroyano
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« Reply #67 on: June 27, 2016, 05:44:30 PM »

Friends I have read the whole thread but I still have some doubts that I will like to ask . Sorry if my question is no so intelligent or dumb.
Ok about LPFP control I have read some times about PWM controller and fuel pump itself have a basic variable applied, fuel pump DC (duty cycle) based in the  low pressure fuel system, "pressure".

Then my big "dumb" question is how is controlled this pressure:
1) by fixed or static map? or
2) it is variable or has an adaptative logic system based in high pressure fuel system, requested AFRs, actual AFRs, etc.... something like a PID control?
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majorahole
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« Reply #68 on: July 08, 2016, 11:49:27 AM »

2
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littco
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« Reply #69 on: July 09, 2016, 02:14:22 AM »

Friends I have read the whole thread but I still have some doubts that I will like to ask . Sorry if my question is no so intelligent or dumb.
Ok about LPFP control I have read some times about PWM controller and fuel pump itself have a basic variable applied, fuel pump DC (duty cycle) based in the  low pressure fuel system, "pressure".

Then my big "dumb" question is how is controlled this pressure:
1) by fixed or static map? or
2) it is variable or has an adaptative logic system based in high pressure fuel system, requested AFRs, actual AFRs, etc.... something like a PID control?

I believe its a variable map that works of the requested and actual pressure, and in cases where the LPFP is weak or fault then the DC has to rise in order to compensate for the low pressures, this then requires higher PW and causes the controller to over heat and shut off, and why some people get that "fuel cut" until it cools down, replacing the pump fixes the issue.

Also if you fit the larger TTRS LPFP and don't amend the map accordingly then again it over heats.

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eliotroyano
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« Reply #70 on: July 11, 2016, 09:51:15 AM »

I believe its a variable map that works of the requested and actual pressure, and in cases where the LPFP is weak or fault then the DC has to rise in order to compensate for the low pressures, this then requires higher PW and causes the controller to over heat and shut off, and why some people get that "fuel cut" until it cools down, replacing the pump fixes the issue.

Nice answer littco, I supposed that too.

Also if you fit the larger TTRS LPFP and don't amend the map accordingly then again it over heats.

But here is where I have the big doubt, if the previous thinking is right why should we need to change LPFP DC map for a different fuel pump or PWM controller? . I mean if the LPFP DC map is basically based in a requested and actual pressure with some other added variables, why we need to tweak related fuel pump maps?
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gman86
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« Reply #71 on: July 11, 2016, 04:05:13 PM »

Nice answer littco, I supposed that too.

But here is where I have the big doubt, if the previous thinking is right why should we need to change LPFP DC map for a different fuel pump or PWM controller? . I mean if the LPFP DC map is basically based in a requested and actual pressure with some other added variables, why we need to tweak related fuel pump maps?

KFFLAF is a basic duty cycle map that runs up to 92%. If you try and run the higher current pump off the stock pwm controller at those duty cycles, it overheats. There is no PID for the pressure, it runs very basic.
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littco
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« Reply #72 on: July 12, 2016, 12:48:37 AM »

Nice answer littco, I supposed that too.

But here is where I have the big doubt, if the previous thinking is right why should we need to change LPFP DC map for a different fuel pump or PWM controller? . I mean if the LPFP DC map is basically based in a requested and actual pressure with some other added variables, why we need to tweak related fuel pump maps?

I think the previous post answered it, the current on the 2 pumps is different so the larger draw causes the controller to over heat and hence why you must lower the map to stop this..
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eliotroyano
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« Reply #73 on: July 12, 2016, 04:09:30 AM »

I think the previous post answered it, the current on the 2 pumps is different so the larger draw causes the controller to over heat and hence why you must lower the map to stop this..

Ok got it........ Wink
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littco
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« Reply #74 on: July 12, 2016, 01:30:12 PM »

Just for note on the fueling
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