Rescaling K-value and AT-question

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JAS
Posts: 15
Joined: Tue Apr 23, 2019 9:13 pm

Rescaling K-value and AT-question

Post by JAS » Wed Apr 24, 2019 4:54 am

Searched and read about rescaling when upgrading injectors from stock,some questions.
Do I have to rescale every single load-map?Not only load-maps for fuel?

Car is equipped with 413 red label and 623chip
M50B25 single Vanos
Injectors upgraded from stock 190cc to 540cc at 3,5bar fuelpressure(Bosch EV6 ..968)
Downloaded XDF and bin from Tunerpro,noticed that stock k-value is 1,0,is that correct?
Have done a small turbo application and i´m getting ready to start up.

I´m struggling to keep my Automatic-transmission,noticed some maps for AT,do anyone know exactly what they are doing?Can I adjust oilpressure in AT from those maps?

Hope somone can help me a little bit or even better can provide a binfile for a boosted M50B25 to start from.

JAS
Posts: 15
Joined: Tue Apr 23, 2019 9:13 pm

Re: Rescaling K-value and AT-question

Post by JAS » Wed Apr 24, 2019 9:09 pm

540cc/190cc=2,84 is the difference for new injectors.

K value 1.0/2,84=0,39 new k value

Still wondering if I need to rescale every single map with Load?Or just fuelmaps?

JAS
Posts: 15
Joined: Tue Apr 23, 2019 9:13 pm

Re: Rescaling K-value and AT-question

Post by JAS » Thu Apr 25, 2019 11:09 am

No one?

Triangulé
Posts: 31
Joined: Wed Jun 06, 2018 10:34 am

Re: Rescaling K-value and AT-question

Post by Triangulé » Fri Apr 26, 2019 2:01 am

Hi JAS,

the new k value is just the cc value difference :

190/540 = 0.352

original k value is 1.00 normally.
You need to be sure of the exact value of the original injectors and compare them at same pressure.
Our M50 was 165cc injectors. I don't think there is differente software revision for the 623

About the rescaling, as you will use very big injectors, you need to take care, as the step between each column will be big, it will not be really precise and the AFR can be a little bit unstable at some rpm.
But anyway this could work.

You need to re scale all the maps related to the load that you will find, taking care to move also the value in the table to have them correspind at the right load.
the most complicated things is to evaluate the max load you will need in the table and modify in the same time the steps between each value.
The minium load need also to be lower.
In fact you need to target a proper injector size for the maw power you target in order to keep maps as precise as possible.

What is your project ? 500 Hp or something like that ? How much turbo manifold do you plan to use ?
What MAF are you going to use ?

JAS
Posts: 15
Joined: Tue Apr 23, 2019 9:13 pm

Re: Rescaling K-value and AT-question

Post by JAS » Fri Apr 26, 2019 2:35 am

Thanks for reply.

192cc at 3,5bar fuelpresssure is oem injectors for m50b25,I´m running green bosch ..968 540cc at 3,5bar.

Lowmounted turbo,T3/T4 hybrid,T3 exhaust with T4 compressor.
Oem MAF M50B25

Aiming for 300-350hp,torque is limiting me due to automatic tranny.Max torque is 310Nm for a 5HP18.
My 5HP18 tranny is equipped with the big converter and also the big cooler,there are smaller converters and coolers for 5HP18,I don´t know which modells have the big or small ones,just know yhere is 2 different sizes.
I´m hoping that I can adjust settings for AT by Tunerpro otherwise I´ll have to dismantle oilpressure-valve inside AT and fix it at a higher pressure.A friend of mine have done this way with pretty good result.
So I hope AT will be able to handle about 400Nm without slip or heating.

as i look at Injection correction,made an excel for the values,there is a sligt difference.
I calulated like this eg for ..968 injectors 9,6V 1465usec=>1465/9,6=152,6
Am I doing it right?

For oem injectors and Binfile for M50b25
7,8 210
9,8V 108
11,7V 72
13,7V 56
15,7V 36

Bosch Green ..968,

8V 2168usec= 271
9,6V 1465usec= 152,6
11,2V 1096usec= 97,85
12,8V 839usec= 65,54
14,4V 655usec= 45,5
15V 596usec= 39,73


New valus to Injector correction map should be something like this,

7,8 300
9,8 140
11,7 85
13,7 50
15,7 34

Am I doing the math OK?

JAS
Posts: 15
Joined: Tue Apr 23, 2019 9:13 pm

Re: Rescaling K-value and AT-question

Post by JAS » Sun Apr 28, 2019 8:19 pm

Replying myself..

Car has been started by now.
K-value was fine and some minor adjustments to Voltage offset and car is running fine when warm.
after adjustments in tables for Temp Compensation cold start works really good now.
Retarded ingnition between 7-15degrees in tables for ignition for all loads above 2000rpm,just for to be sure and safe when start testdriving.
Needs more fuel PT tables,it´s lean when driving normally.
Quick testdrive yesterday,turboboost is coming just below 2500rpm,need lots of more fuel when boost is coming.
Massive torque when boost rises....About 7psi(0,5bar) so far.

JAS
Posts: 15
Joined: Tue Apr 23, 2019 9:13 pm

Re: Rescaling K-value and AT-question

Post by JAS » Sat May 04, 2019 12:32 pm

Some testing done.
Somehow I need to rescale load-axis.
Due to lower k-value for injectors it now only hits about 50% of load-axis.
Can anyone please advise me how to rescale load?

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