Timing calculator v3

2004LB7

Well-known member
Dec 15, 2010
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Norcal
The numbers calculated are basically what I used when I had an LB7. I just had to calculate and add them manually. Took forever. At the time I couldn't figure out a way to make it work in excel until recently when another member asked if I can take another look at it.

It ran good in my truck and took care of the shift issues but the other tables are unlikely to be what your tables are so I don't know if it would work across all trucks. If my method is correct then it should. But I have no way of testing it now
 

Chavez91

People Go Outside?
May 30, 2012
139
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Heh. Wouldn't you like to know
I need to revisit LB7 and LLY defuel. I started chasing it in my IDA projects on how it actually is calculated. With all this corona nonsense going on, I just might find some time here soon just before L5P kidnaps me..... again :secret:

But with the things Ive learned over the years, there are alot of new techniques learned that involve the relationship of MM3 to Torque that is sorta a taboo in the duramax world as we have lacked the access to the necessary stuff.

But I will say, scaling out your MM3 and torque to the proper numbers DOES make the world of difference in how the truck runs and shifts... some ECMs have limitations on how high you can go (most are much much higher than what EFILive imposes on its users) but getting as close as possible helps a ton!

One thing I will say, there is a torque table in the TCM that isnt mapped that also plays a huge role in how the truck defuels. There is more AL5 coming opensource coming soon too. Obviously as I find spare time.
 

Yngdmax92

Member
Sep 26, 2013
876
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unless you know what you are playing with and understand the tables in great detail, its best to not mess with it. you can start killing the trans in a hurry if you just go shoving numbers in and testing it out in the truck.

WOT defuel is the one to really be careful on, part throttle is usually overly aggressive the moment you start adding in more power so there is room to mess with it IF you know what you are doing in there. small changes can make a BIG difference and you need to run the truck for a little while and log to see how it learns in.

Must be most tuners don't really mess with it? More or a personal thing. The tcm tunes I have purchased did not feel any different other then the simple raise the shift points at wot. Maybe idk. I guess I should of logged it before and after.
 
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Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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Phoenix Az
Must be most tuners don't really mess with it? More or a personal thing. The tcm tunes I have purchased did not feel any different other then the simple raise the shift points at wot. Maybe idk. I guess I should of logged it before and after.
it just depends on who it is and what you have done. in most cases, you dont need to change it much, if at all. years ago, steve learned the tables really well and wanted me to try his defuel in my truck. made a big difference on larger injectors, stock injectors didnt really need it due to the way the tables work and what was adjusted in my tune. I know blake has got this dialed down now as well. It may not be good right off the bat but some logging and some tweaks can get you there. sitting in the truck is best to really make defuel work because everyone describes it differently.
 

RMJ_LB7

Member
Feb 25, 2020
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Here is some other calculators I have created with another member on here but haven't had anything to test them on. use at your own risk

The one I would most like feedback on is the defuel calculator for LB7 & LLYs. if anyone wants to try it out and give us your opinion I would appreciate it
I will see if I can create a simple 100HP tune using the defuel calculator for my 02 daily... The daily is stock other than a lift pump. I will keep you updated, my biggest thing is does anyone already have a awesome logging file for the LB7 that they wouldn't mind sharing?
 

Gomez599

New member
Jun 27, 2020
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Where it says to copy and paste timing base B, are you guys just copying that in the ''stock'' form its in? as in, you modify your pulse, and fuel tables and then just leave timing base B alone and copy it into the spreadsheet and then it shows you what to use for your injection timing?? sorry to sound dumb..ive read the entire starlite diesel tuning book and have been studying my ass off and came across this timing calculator. Just unsure of this 1 thing and don't want to mess timing up.
 

Dozerboy

Well-known member
Jun 23, 2009
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The Version three of joshs spreadsheet has a lot more calculations. You just need to enter fuel pressure, pulse width, and injection percent compared to BTDC. Then it will give you your new timing table. Those are the top few sections of the spreadsheet. The last few are for making “custom“ timing Tables with different % of BTDC I wouldn’t mess with those until you learn more about tuning and timin.
 

2k6lbzdmax

New member
Aug 10, 2020
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when creating the new timing table kind of like what gomez599 was saying do you use the stock GM timing b table? in reference with your desired pulse width and fuel pressure?
 

Dozerboy

Well-known member
Jun 23, 2009
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You can but that only going to show you what GM did for timing. You want to make your own not match theirs. You make your own by using the BTDC % and winging it based on timing information you have.
 

2k6lbzdmax

New member
Aug 10, 2020
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You can but that only going to show you what GM did for timing. You want to make your own not match theirs. You make your own by using the BTDC % and winging it based on timing information you have.
Right but when using the calculator when they ask for timing table B your using gms stock table? Which then spits out the new tsble based on your pressure and pulse with modifications?
 

JoshH

Daggum farm truck
Staff member
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Feb 14, 2007
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Right but when using the calculator when they ask for timing table B your using gms stock table? Which then spits out the new tsble based on your pressure and pulse with modifications?
You don't have to copy the timing table into it to use the calculator. You only need the pulse width and fuel pressure tables.
 

JoshH

Daggum farm truck
Staff member
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Feb 14, 2007
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Not to take any credit away from JoshH,

I'd just adjusted the spreasheet for the E98 LWN 2.8 Duramax (Baby Max)

Cheers.
I left it all open for modifications exactly for that reason. Thanks for sharing your addition.
 
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Yourmom

New member
Mar 15, 2021
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This is the most up to date version of the calculator I have. If anyone has another version they have modded for their use, I would love to see the kind of changes you are making. I didn't password protect it because I wanted people to be able to customize it to fit their wants/needs. Maybe there are some changes others would like to use as well.
what units does the calc expect for each table?
 

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