CRAI8 fuel modeling and scaling clarification

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redtopracer
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CRAI8 fuel modeling and scaling clarification

Unread post by redtopracer »

Ok, upon further digging, Ive come to the realization that Im not 100% on what needs to happen with the new crai8 xdf and the fueling and scaling.




All of the SP functions in the new xdf scale down to the correct values I have for my injectors. Same with the MAF. Ditto SARCHG




Now do I need to put the unscaled values in there? And leave the global scaling percentage at what it is(10.8158)?



Or if that is all correct as is ie scaled values in those fields, am i good to just hit 30 in the k constant and send her?
decipha
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Re: CRAI8 fuel modeling and scaling clarification

Unread post by decipha »

simple 3 step

first is always verify k constant is 30 in all tunes no exception

second you plug in your actual high slope

third do everything else

as always be sure to read the comments on the parameters
redtopracer
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Re: CRAI8 fuel modeling and scaling clarification

Unread post by redtopracer »

Ok, when I change any of the SP functions it changes the SP scalar percentage.



when i open the BIN with the new CRAI8 xdf, SP scalar is %1085.18


When I follow your notes and instructions, and put in the straight unscaled values. It drops the SP percentage scalar to %71.47


What should the SP scalar be at?
decipha
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Re: CRAI8 fuel modeling and scaling clarification

Unread post by decipha »

scaing percentage doesnt matter you have no reason to look at it

simply plug in your actual your high slope
redtopracer
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Re: CRAI8 fuel modeling and scaling clarification

Unread post by redtopracer »

Ok, so when I open up the SP functions after putting in the straight values like in the instructions. Are they still supposed to be scaled to the SP scalar? Or are they supposed to be the straight value I just entered?
decipha
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Re: CRAI8 fuel modeling and scaling clarification

Unread post by decipha »

there is no scaling all values should be actual unscaled values

thats the purpose in the k constant

if your unsure just set the scaling percentage scalar to 1
redtopracer
Posts: 97
Joined: 2021 Mar 24, 10:32
Location: springdale arkansas
Vehicle Information: 98 mustang gt 5 spd

Re: CRAI8 fuel modeling and scaling clarification

Unread post by redtopracer »

ok, finally got craj0 bin on the crai8 xdf to accept the inputs per your instructions. Had to convert and manually enter the 90mm cobra maf, and it finally took all the straight values in the order you instructed to enter them. And it didnt work. Fuel was .34 lean car barely ran. If I dont touch anything it runs the craj0 bin in varying degrees of success. Gonna reattempt with the crai8 bin tonight.

Really hope I can get this working, this XDF is significantly more fleshed out. Might even be able to convert to mechanical idle air if I can get her going.
decipha
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'19 F-150 3.3L

Re: CRAI8 fuel modeling and scaling clarification

Unread post by decipha »

u cant use a craj0 file with the crai8

you have to use the strategy the file is for
redtopracer
Posts: 97
Joined: 2021 Mar 24, 10:32
Location: springdale arkansas
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Re: CRAI8 fuel modeling and scaling clarification

Unread post by redtopracer »

I get similar results with CRAI8 bin modified as instructed.



Basically still having all fuel, and air scaled by the SP scalar, so while the high slope, low slope, breakpoint, k constant, SARCHG, and Fn036 all have the straight values as instructed. The SP**SCALAR is cutting them to like 70% of there actual value. And moving the SP scalar auto moves the other values.
decipha
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Joined: 2021 Feb 15, 12:23
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'19 F-150 3.3L

Re: CRAI8 fuel modeling and scaling clarification

Unread post by decipha »

I think I understand now whats going on. Your wanting to view an existing tune unscaled rather than create one.

Reopen your original tune and just change the high slope to your actual high slope and done.

This is assuming you changed the k constant value from something other than 30. You cant do that if trying to see the actual values in a current improperly scaled tune.

In that case reopen your original file and change only the high slope to your actual injector high slope value. You can leave it at that. If however you wanted to scale it properly then copy out all the SP values first before changing the k constant to 30 and set the high slope to your actual high slope you can then paste back in all the SP values youve copied out.
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