vjborelli
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« on: May 14, 2015, 10:17:22 AM »
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So I've been looking at possibly modifying KFURL and KFPRG as a possible way to account for volumetric efficiency and scavenging gains from modifications to the intake and exhaust system.
FrankenTurbo F21L w/ EV14 550cc injectors
Currently modifications on the exhaust side:
F21L high flow manifold
Unitronic HFC & 3" Downpipe
Center resonator deleted
Magnaflow rear mufflers
Currently modifications on the intake side:
AWE Tuning FMIC
3" MAF housing
My thoughts are that with the exhaust side modifications, scavenging efficiency should be increased. Team that with some adjustments to the VVT tables, and volumetric efficiency should see an increase. And if I am to understand correctly, KFURL is a factor for VE, while KFPRG represents residual gas in the cylinder after scavenging.
Am I on the right path, or way off?
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prj
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« Reply #1 on: May 14, 2015, 01:55:46 PM »
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It's not too important to have this right because it is not really used for anything besides conversion back and forth when you have a MAF.
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Jim_Coupe
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« Reply #2 on: May 25, 2017, 01:47:46 AM »
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It's not too important to have this right because it is not really used for anything besides conversion back and forth when you have a MAF.
Prj is it worth it to edit KFURL when runing a larger turbo like GT28? I know there was a thread about this recently but cant find it  |
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E85oholic
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nyet
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« Reply #3 on: May 25, 2017, 10:32:56 AM »
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Prj is it worth it to edit KFURL when runing a larger turbo like GT28? I know there was a thread about this recently but cant find it Why would a larger turbo affect VE? |
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prj
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« Reply #4 on: May 26, 2017, 04:05:03 AM »
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Because he does not understand what it does and just changes maps  But actually a larger turbo can affect VE. Especially up top your VE will be better at the same pressure due to lower backpressure from the larger turbine wheel and housing. |
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Jim_Coupe
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« Reply #5 on: May 26, 2017, 02:51:57 PM »
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LOL i was askin to learn and also to find a good thread about it.. Yes i just changes maps sometimes i don know what they do.. therefor i must try and error. But feel free to think what ever you want...  |
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E85oholic
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prometey1982
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« Reply #6 on: July 09, 2023, 10:00:49 AM »
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Because he does not understand what it does and just changes maps But actually a larger turbo can affect VE. Especially up top your VE will be better at the same pressure due to lower backpressure from the larger turbine wheel and housing. If changing of these maps isn't important then what maps should be changed in case of changing engine displacement? So if I have 2.5 liter engine's flash and want to use this flash on 2.0 engine what problems will I have? I'll plan to use KISRM, KFPRGs and KFURLs maps from 2.0 flash. |
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prj
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« Reply #7 on: July 09, 2023, 03:05:58 PM »
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If your engine has a MAF, it does not really matter.
Also you can not change any of this shit without having the car (or even better the engine) on a dyno and going through it.
Your injectors need to be fully calibrated OR you need an additional pressure sensor in the manifold and then calibrate the model so that ps_w = real pressure in manifold.
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prometey1982
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« Reply #8 on: July 09, 2023, 11:01:10 PM »
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If your engine has a MAF, it does not really matter.
Also you can not change any of this shit without having the car (or even better the engine) on a dyno and going through it.
Your injectors need to be fully calibrated OR you need an additional pressure sensor in the manifold and then calibrate the model so that ps_w = real pressure in manifold.
Ok, understood. But I have both firmwares for 2.0 and 2.5 engines. Customer wants to move to software with fuel pressure sensor. He has 2.0 engine for which firmware with fuel sensor is not exists. So my plan is move displacement depend maps to 2.5 software. I understand that all are motor depend but some changes has the most reliable value and some has minor. |
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prj
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« Reply #9 on: July 10, 2023, 06:03:28 AM »
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From memory (double check FR to be sure):
(ps_w * KFURL + KFPRG)*KFPBRK = rl_w.
With a MAF it goes both ways, first from rlroh_w to pressure and then reverse to rl_w.
With sensor in manifold it only goes once from pressure to load.
KISRM is integrator, basically a rate of change limiter. dpfsg_w gets calculated based on previous iteration and then multiplied by it.
So really with a MAF it makes no difference, only the ps_w will be wrong and requested load, because requested load works off of ps_w/pssol_w.
The load itself will not change at all. On a MAF car it depends purely on KUMSRL, which is a constant to calculate mass flow into load.
Load was defined in earlier Motronic as injection time to reach lambda 1. In newer ECU's this was dropped but 100% load is generally considered to picked to be somewhere around WOT with atmospheric pressure.
So if you flash 2.5 firmware on there, then adjust KUMSRL and the manifold model to have the correct load and ps_w, then your entire ECU calibration is trash.
Everything from ignition maps, injection maps to torque and idle maps.
Easier to add your fuel pressure sensor capability in some limited form in ASM.
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prometey1982
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« Reply #10 on: July 10, 2023, 10:25:26 AM »
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Ok, got it. Thanks!
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