Crome Cell value Tips
02-26-2008, 12:24 AM
#1
0.0 BAR
Thread Starter
Join Date: Aug 2007
Posts: 39
Crome Cell value Tips
Well i search and i didn't find anything in here so i'm going to give you guys a little tip.. i know there are some of you guys that know this. but there are plenty that don't
here are a couple equations in order to convert the numbers in each cell into injection ms that are shows in the 2d graph
Cell value X 0.01724739 = injector ms
inj ms divided by 0.01724739 = cell value (so you can go back and forth from one unit to the other)
so whats the point of this you may ask...
You can use this to calculate a target A/f and suggested inj ms. here is how it work
(for people with crome free and freelog)
after you log, you could use your actual a/f to calculate how many ms you want your injector to open to get a target A/F.
lets say you got 11.32 a/f at 7000rpm and you want 12.9.... 11.32 divided by 12.9 =0.877 this is your fuel multiplier and you multiply your injector ms by this number and will get your suggested inj ms.. lets say you inj ms is 9.30ms... multiply
9.30ms * 0.877 = 8.15ms this is your new inj ms..
Crome doesn't show the exact inj ms in there scale, in order for you to see the exact timing you have to click and drag up and down the points on the 2d graph.... OR you can just divide the cell value by 0.01724739 to get your inj ms
here is what i always do.. I made a table on exel and i always print one for each car, it look some what like this:
(example for 12.9 A/f target)
LOG A/F Inj MS fuel multiplier New ms new cell value
500 13.5 7.39 x 1.046 = 7.72 / 0.01724739 = 447
1000 13.7 7.39 x 1.062 = 7.50 / 0.01724739 = 434
1203
bla bla bla
Always, Always, Always divide yout LOG A/F by your Target A/F
I only know the basics of exel but i'm sure you can make a taple that can spew out all this.. you just have to input the amount.
I hope this can help people out, it only takes me about 3 pull to get the WOT A/f where i want it on NA cars and some turbos.
here are a couple equations in order to convert the numbers in each cell into injection ms that are shows in the 2d graph
Cell value X 0.01724739 = injector ms
inj ms divided by 0.01724739 = cell value (so you can go back and forth from one unit to the other)
so whats the point of this you may ask...
You can use this to calculate a target A/f and suggested inj ms. here is how it work(for people with crome free and freelog)
after you log, you could use your actual a/f to calculate how many ms you want your injector to open to get a target A/F.
lets say you got 11.32 a/f at 7000rpm and you want 12.9.... 11.32 divided by 12.9 =0.877 this is your fuel multiplier and you multiply your injector ms by this number and will get your suggested inj ms.. lets say you inj ms is 9.30ms... multiply
9.30ms * 0.877 = 8.15ms this is your new inj ms..
Crome doesn't show the exact inj ms in there scale, in order for you to see the exact timing you have to click and drag up and down the points on the 2d graph.... OR you can just divide the cell value by 0.01724739 to get your inj ms
here is what i always do.. I made a table on exel and i always print one for each car, it look some what like this:
(example for 12.9 A/f target)
LOG A/F Inj MS fuel multiplier New ms new cell value
500 13.5 7.39 x 1.046 = 7.72 / 0.01724739 = 447
1000 13.7 7.39 x 1.062 = 7.50 / 0.01724739 = 434
1203
bla bla bla
Always, Always, Always divide yout LOG A/F by your Target A/F
I only know the basics of exel but i'm sure you can make a taple that can spew out all this.. you just have to input the amount.
I hope this can help people out, it only takes me about 3 pull to get the WOT A/f where i want it on NA cars and some turbos.
02-26-2008, 01:10 AM
#3
0.0 BAR
Join Date: May 2005
Posts: 0
Re: Crome Cell value Tips
Let me show you why all of your work is worthless and a waste of time.
( AFR / Target AFR ) = Fuel Mult
Cell Value * 0.0172 = Inj ms1
Fuel Mult * Inj ms1 = Inj ms2
Inj ms2 / 0.0172 = New Cell Value
SUMMED UP:
(AFR / Target AFR ) * ( Cell Value * 0.0172 ) / ( 0.0172 ) = New Cell Value
Waste of time since you are multiplying by 0.0172 and then dividing by 0.0172. WASTE OF TIME. It equals one.
( AFR / Target AFR ) * Cell Value = New Cell Value
Why convert when you are just going to covert back. That's like converting miles to feet, but coverting miles into lightyears first.
02-26-2008, 01:47 AM
#4
0.0 BAR
Thread Starter
Join Date: Aug 2007
Posts: 39
Re: Crome Cell value Tips
1.Calm down...
2.Read better...
3.if you don't want to go point by point clicking up and down in the 2d graph for you to get your actual inj ms... JUST DIVIDE YOU CELL VALUE BY 0.172 AND THAT IT....
I DIDN'T SAY (Cell value*0.0172) / (0.0172) new cell value... that is none sense
cell value /0.172= ACTUAL INJ MS... SO YOU DON'T WASTE YOUR TIME TRAYING TO FIGURE IT OUT IN YOUR 2D GRAPH THAT ALL.
2.Read better...
3.if you don't want to go point by point clicking up and down in the 2d graph for you to get your actual inj ms... JUST DIVIDE YOU CELL VALUE BY 0.172 AND THAT IT....
I DIDN'T SAY (Cell value*0.0172) / (0.0172) new cell value... that is none sense
cell value /0.172= ACTUAL INJ MS... SO YOU DON'T WASTE YOUR TIME TRAYING TO FIGURE IT OUT IN YOUR 2D GRAPH THAT ALL.
02-26-2008, 12:27 PM
#5
0.0 BAR
Join Date: May 2005
Posts: 0
Re: Crome Cell value Tips
Originally Posted by Zriuz
so whats the point of this you may ask... You can use this to calculate a target A/f and suggested inj ms. here is how it work
You can use this to calculate a target A/f and suggested inj ms. here is how it work You said it right there. "Use this to calculate target AFR"
Thus, my point. You don't need to know injector opening time to calculate target AFR.
02-27-2008, 05:14 AM
#10
0.0 BAR
Join Date: May 2005
Posts: 0
Re: Crome Cell value Tips
Originally Posted by Zriuz
post your own formulas.. so the rest of the board can learn. 
AFR / Target AFR * Value = New Value
This is not mine, yours, or anyones. This is simple mathematics. It goes with tuning ANY EMS. Really, any.
