Global K Constant / Scaling Percentage

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DOHCTOR_32V
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Global K Constant / Scaling Percentage

Unread post by DOHCTOR_32V »

I have a known, good CBAZA tune, but when I try to drop the MAF transfer, injector slopes, breakpoint and offset into T4M2, the engine gets a bad lean pop and fueling is off. There is something I'm not grasping about the descriptions and instructions concerning the slopes, scaling percentage and k constant. I see no DO NOT EDIT - High slope parameter that is mentioned. I have the OEM, 24Lb, Cobra injectors and data. Could someone please spell out what I need to enter, in order to use and display my known good data and MAF transfer? I assume my data is getting scaled wrong, due to my mistake / misunderstanding.

These are the standard T4M2 settings
Slopes.png
This is what I recently came up with that seems okay to me, but I will wait until I get feedback. I don't want any more lean pop issues. All of the minimum T4M2 setup guidelines were applied in previous trials. Still not sure about the scaling percentage, since J4J1 doesn't correspond.
Slopes 2.png
decipha
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Re: Global K Constant / Scaling Percentage

Unread post by decipha »

you have to change the high slope first
DOHCTOR_32V
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Re: Global K Constant / Scaling Percentage

Unread post by DOHCTOR_32V »

Okay. I changed only the high slope to 24.84 first, in a fresh T4M2 bin. I enter the low slope of 24.84 - I try to pull the MAF curve from a good tune, from within the compare feature - the known, good, MAF transfer in compare has increased all kg/hr entries up one decimal point. Seems to multiply them by 10.306, which is the J4J1 scaling % which has not been entered at all, only shown in compare. I change SARCHG to 301.89 - K constant stays at 30. Scaling % goes to .8280 automatically.
Min PW changes itself from the correct injector data of 1.4ms to 0.401, after I enter 1.4ms and save.

I don't get it.
decipha
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Re: Global K Constant / Scaling Percentage

Unread post by decipha »

sounds like everything is working perfectly

obviously you have the high slope set to 256 lbs/hr in your j4j1 tune your copying from

I have minpw clipped to .4 and should always be set to 0.

read the fuel write up you missed the info about scaling percentage
DOHCTOR_32V
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Re: Global K Constant / Scaling Percentage

Unread post by DOHCTOR_32V »

decipha wrote: 2022 Jun 29, 08:10
obviously you have the high slope set to 256 lbs/hr in your j4j1 tune your copying from
The J4J1 tune is a solid carry over from Binary Editor which shows SARCHG of 301.08, slopes as 24.84 and the MAF transfer 10.306 times less in kg/hr than TunerPro. I'm not sure why that is the case, but TunerPro always has shown those values to be 10.306 times higher. I guess it is caused by the XDF scaling percentage. How do I get around that, if I want to tune a stock bin in TunerPro? I will attach a pic of a an unmodified J4J1 and T4M0 in TP.
.
slopes 3.png
DOHCTOR_32V
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Re: Global K Constant / Scaling Percentage

Unread post by DOHCTOR_32V »

I read the fuel writeup again. Should my known MAF curve be put into the T4M2 tune with the existing kg/hr values scaled, / .828? For example BE shows 1302 kg/hr and TP shows 13,418 kg/hr due to the 10.306 times scaling. I need 1302 / .828 "new SP" = 1,572.46 for that entry??

or better yet, is the following correct?

Using 24 lb/hr Cobra injectors

*My new injector data = 24.84 / 30 = .828 new scaling percentage

*High slope = 24.84

*Low slope = 24.84 / .828 = 30 lb/hr

*Break point = .0000100136 / .828 = .0000120937

*MAF transfer = known kg/hr - all entries / .828 "new SP"

*SARCHG = 301.08 / .828 = 363.62

*Min PW = 0

* Global K-constant stays at 30
decipha
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Re: Global K Constant / Scaling Percentage

Unread post by decipha »

The stock high slope in a completely unmodified j4j1 tune is the default value of 256 lbs/hr in tunerpro since the high slope isn't set. You need to set it to 24.84 to display accurate data in tunepro. Or you can just download the stock j4j1 file from the same thread you downloaded the cbaza adx and xdf and you'll see its already got the high slope set correctly.

This is convered in the fuel write up. http://efidynotuning.com/fuel.htm#k_constant
Under the existing tune section. You have to open your existing file and set the high slope to the correct value instead of the default 256 lb/hr value.

You cannot put the maf curve in until after you plug in the k-constant and the high slope. Then all SP** values have to be put in.

Tunerpro displays all unscaled values so you plug in the actual values no scaling or any of that funky jazz needed even if you have 210 lb/hr injectors you plug the actual injector data in.
DOHCTOR_32V
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Re: Global K Constant / Scaling Percentage

Unread post by DOHCTOR_32V »

decipha wrote: 2022 Jun 29, 14:00

You cannot put the maf curve in until after you plug in the k-constant and the high slope. Then all SP** values have to be put in.

I thought the k-constant has to stay at 30 in T4M2? Or are you saying to change k constant to 30 in the stock J4J1 to start from the "ground up" with a stock bin in TunerPro with it's XDF?
DOHCTOR_32V
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Re: Global K Constant / Scaling Percentage

Unread post by DOHCTOR_32V »

Here is what I have now - T4M2.bin

Using 24 lb/hr Cobra injectors

*My injector data = 24.84 / 30 = .828 new scaling percentage

*High slope = 24.84

*Low slope = 24.84

*Break point = .0000100136 / .828 = .0000120937 - not sure if this is supposed to be scaled.

*MAF transfer = from a known, good tune kg/hr - all entries / .828 "new SP"

*SARCHG = 301.90 / .828 = 364.61

*Min PW = 0

* Global K-constant stays at 30
.
slopes 5.png
decipha
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Re: Global K Constant / Scaling Percentage

Unread post by decipha »

it does stay at 30 make sure and verify its at 30

if u change the k constant in any tune your changing everything

there is no scaling in tunerpro its all accurate actual values

You have to open the high slope scalar by itself and set it. You cant open any other parameters til after you do thr high slope.
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