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Author Topic: 1.8t agu m383 tuning  (Read 911 times)
moritzmkiv
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« on: March 02, 2024, 02:15:42 PM »

Hey guys,

so i started working on my agu software with the guide providesd here in the forum and i came along some problems:
i work with sotware partnumber cj even tough i have bb ecu because of mappack availability. seems to work so far.
mods on the car are: k04001 maxpeedingrods turbo, 440/470 injectors, vr6 maf housing.

first, i changed fgat0 grundanpassungsfaktor and changed MAF linearization with mazer tool. is this necessary, because increase in both areas could even out? wich map do i change first then?

second, i have an understanding problem with ldr sollwert. does this map take the maf calculated load and adapts n75 to set the right boost pressure, or is it the other way around, that this map just gives a tolerated operation window for the boost pressure?
when i would change nothing here, the bigger turbo would make bigger air mass with the given n75 values, but i would get a fault code because the values would get out of given limits.

as you can see im a little confused now. im just starting on chiptuning, but somewhere i got to start.
im thankful for any help. but please spare me out with that "don´t do it, youre not a pro" arguments. ive been searching for a professional for a long time, but it seems tuners that are common with this stoneage ecu are pretty rare.

Thanks for any help and best regards!
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ZpiXDK
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« Reply #1 on: March 07, 2024, 10:51:57 AM »

First of all, get a new fuel pump if you want to install bigger injectors on this old AGU.
- Or atleaset check the fuel pressure!

Second, tune one thing at a time!
-My advise, keep it stock, get the MAF tuned so it runs like stock, then you can tune injectors afterwards.

http://nefariousmotorsports.com/forum/index.php?topic=1123.0
FGAT0 explained.

If you change your MAF you need to change Linarization.
- Get a complete VR6 MAF and you just copy from the VR6 file.

Doing random change to both will not even anything out Smiley

All the info you need is here on the forum

With that turbo, you could just max out your stock injectors (Maybe just a 4Bar FPR, but again you need new fuel pump)

KFLDS is your "requested boost" (requested load), when you make the numbers bigger, you allow for more load, and the turbo will produce more boost, to keep up with the load.
- I assume it runs like most of other ECU's, so KFLDTV (N75) is the base map for duty cycle. then it use the PID to control outside of that (KFLDP, KFLDI, DLDRN)
- If you only change KFLDS it will make more boost.
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You want some tuning with that pop and bang?
-Nahh it’s not good for the engine
prj
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« Reply #2 on: March 08, 2024, 02:21:43 AM »

It's not possible to tune it correctly with FGAT0 because load calculation is capped in ECU.
If you simply reduce FGAT0 and scale the MAF correctly then you hit the load cap and ECU stops calculating load.

The only way is to recalculate the load. Load is injection time to reach lambda = 1.
Recalculating load means changing every map that has load, and also changing the cold start factors, because they depend on it.

A very big job.

I have done this for R32 mk4 automatic MAF and 440cc bosch green giant injectors (968) a long time ago.
I have posted about this before, including the pinout how to connect the HFM5...
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moritzmkiv
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« Reply #3 on: March 08, 2024, 02:14:16 PM »

It's not possible to tune it correctly with FGAT0 because load calculation is capped in ECU.
If you simply reduce FGAT0 and scale the MAF correctly then you hit the load cap and ECU stops calculating load.

The only way is to recalculate the load. Load is injection time to reach lambda = 1.
Recalculating load means changing every map that has load, and also changing the cold start factors, because they depend on it.

A very big job.

I have done this for R32 mk4 automatic MAF and 440cc bosch green giant injectors (968) a long time ago.
I have posted about this before, including the pinout how to connect the HFM5...

I read a "how to" where it states that you don't want to change khfm which I see as kind of load factor, and I think that's what you're referring to.
What they say is, instead of turning air mass factor up and injector factor down, try getting similar % change at both factors hardware-wise and get the rest done with injector factor.
I would say that's because the ECU just thinks it knows what fuel/air mass ratio is and defines that as load. When you change hardware similar, the factor should stay the same.
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prj
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« Reply #4 on: March 09, 2024, 09:35:48 AM »

I read a "how to" where it states that you don't want to change khfm which I see as kind of load factor, and I think that's what you're referring to.
What they say is, instead of turning air mass factor up and injector factor down, try getting similar % change at both factors hardware-wise and get the rest done with injector factor.
I would say that's because the ECU just thinks it knows what fuel/air mass ratio is and defines that as load. When you change hardware similar, the factor should stay the same.

Load = injection time to reach lambda 1 on this ECU. That's why it's measured in ms. Relative load only came with ME7.
If calibrating it correctly you should never touch FGAT0 at all.

All previous older ECU's also did it the same way. The lambda maps are simply corrections for this injection time, but the base load it calculates already takes into account the injectors.
Of course doing such drastic modifications to load means a lot of other shit has to be recalculated, so some mix can be used of FGAT0 and KHFM.

There is a hard cap on load 12.75ms. Your calculated load can never exceed that. Normally your calculated load should not exceed about 11.5ms, so you still have some room for safety, like boost cut etc.
If you ever reach 12.75 then load stops being calculated. That means fuel instantly goes lean, because it can not see any more cylinder filling and ignition keeps going on the same column.

As I said, it's a big job to do this right.
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ZpiXDK
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« Reply #5 on: March 11, 2024, 08:45:49 AM »

To understand the "load" better, look at the explanation I gave here:
http://nefariousmotorsports.com/forum/index.php?topic=20919.msg158683#msg158683
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You want some tuning with that pop and bang?
-Nahh it’s not good for the engine
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