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matchew
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« Reply #15 on: August 29, 2012, 08:21:05 PM »

I think you have KRKTE wrong, what address/factor are you using?
« Last Edit: August 29, 2012, 08:50:54 PM by matchew » Logged
masterj
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« Reply #16 on: August 30, 2012, 03:51:47 AM »

Please look at my post here: http://nefariousmotorsports.com/forum/index.php?topic=2418.msg22745#msg22745
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matchew
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« Reply #17 on: August 30, 2012, 07:57:04 AM »


What about it? It has NO useful information to do with this post.
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Bische
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« Reply #18 on: August 30, 2012, 08:51:42 AM »

I think you have KRKTE wrong, what address/factor are you using?

16bit lohi, 1D744, 0.000111

I have ran some different tests, and I have found the problem. The problem is the stock axis, it is way too short and when I run above/under the axis the ECU will extrapolate the curve, I believe this is done to prevent the mixture from running uber lean in the basic calculation if the boost would spike or just being able to build alot higher than requested in the stock calibration(0.6bar boost in my case).

It does however seem to hit a roof at ~2150mbar, I would suspect this is some 8bit cap but im not too good regarding that stuff.

Here is a fast cook up I did:


Which resulted in this:


I will refine this with better calculations and post the results.
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Bische
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« Reply #19 on: August 30, 2012, 11:01:53 AM »

Ok, here is my new calculation:


Lets break it down:

1131cc@4bar = 894cc@2.5bar(4bar - 1500mbar)

1131 / 894 = 1.2651

That is how the stock values are calculated IF they were to use the standard -1200 -1000 -800 -600 -400 -200 axis mentioned in the FR, the axis found in my binary is actually that one divided by 4 for some weird reason. If I enter that axis, all stock Z values lines up with the calculation I did above.

As for the KRKTE, I just simply divided old injector flow with new flow and used that factor to multiply the old KRKTE.

I have a good feeling about this one and I hope to finally get my fueling dialed, so I can start tuning for horsepower.
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Bische
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« Reply #20 on: October 15, 2012, 11:49:30 AM »

Forget about my last posts. The stock axis IS correct, however my definition was wrong and showing the axis divided by 4.

I changed that up and started tuning, and even with the right calculation from the FR I was getting bad results. I now have it pretty much spot on after ALOT of trial and error.





Im attaching a small excel sheet I made to calculate the FRLFSDP and KRKTE, if someone is tuning a returnless system please try it out and see how it works for you.

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dantt
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« Reply #21 on: September 25, 2013, 01:38:52 AM »

hi!
I'm considering changing my standard fuel pressure regulator (3bar) with a 4 bar one, on my TT 1.8T 225.
at the time I have only map and filter. is useful to change the fuel pressure regulator?

in attached my FRLFSDP. in this table there are only 1.0000

if I understand the rule to fill this table (http://nefariousmotorsports.com/forum/index.php?topic=460.0)
FRLFSDP pdr evmes = V / (pdr akt + (pu-ps))
Where in pdr evmes = absolute pressure in the fuel circulation upstream of the injection valve at measuring Qstat
(3000 hPa)

in my case ( i think ) FRLFSDP know id = 1 = V 3/3

will i have to replace 1.00000 with V4 / 3??

I also read that I have to increase by 15% KRKTE,  is ok?

Thanks in advance
Daniele
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dantt
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« Reply #22 on: September 25, 2013, 03:12:13 AM »

....

Im attaching a small excel sheet I made to calculate the FRLFSDP and KRKTE, if someone is tuning a returnless system please try it out and see how it works for you.



i have tri to use it, but probably I made a mistake

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dantt
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« Reply #23 on: September 26, 2013, 12:46:44 AM »

any help for me?
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engine_nerd
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« Reply #24 on: May 25, 2014, 05:36:51 PM »

Dan,

This map is only for cars with returnless- static fuel pressure. They need compensation in the required fuel mass modeling because the effective flow rate changes with intake manifold plenum pressure.

Your TT has a 1:1 ratio fuel pressure regulator- as such, the pressure delta between fuel being injected and the air stays constant. This means that no correction is needed and that is why your table is 1.00 everywhere.

You probably won't see this as it's an old post but might as well answer the question for posterity's sake.
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dantt
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« Reply #25 on: May 27, 2014, 08:22:46 AM »

thanks for your replay
I would like to mount a 4bar fuel pressure regulator on my TT 225
now i have understand that i need to change only KRKTE and kvb

http://nefariousmotorsports.com/forum/index.php?topic=5079.msg49155#msg49155

Dan,

This map is only for cars with returnless- static fuel pressure. They need compensation in the required fuel mass modeling because the effective flow rate changes with intake manifold plenum pressure.

Your TT has a 1:1 ratio fuel pressure regulator- as such, the pressure delta between fuel being injected and the air stays constant. This means that no correction is needed and that is why your table is 1.00 everywhere.

You probably won't see this as it's an old post but might as well answer the question for posterity's sake.
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hipeka
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« Reply #26 on: May 27, 2014, 11:45:09 PM »

Fuel pressure change will also affect to TVUB values. So you must also correct those as well.

thanks for your replay
I would like to mount a 4bar fuel pressure regulator on my TT 225
now i have understand that i need to change only KRKTE and kvb

http://nefariousmotorsports.com/forum/index.php?topic=5079.msg49155#msg49155

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