Im dumb, Help me with my wideband question and I'll give you a discount!
 

Ok so I finally got my 3rd wideband (2 bad widebands in a row from Innovate). Well it works and I am datalogging with ecucontrol but I have to log the raw wideband voltage. I need a formula to convert the voltages into a/f ratio's. I havent taken math for years and can't remember.

Example:
0v = 7.35afr
5v = 22.39afr

So I need to figure out what the incriments of voltage would correspond to as afr's.....like 3.78v would be ?? I would think there is a formula to work it out in excel, any input would be helpful, I'll throw a discount on any of my products to whoever can do this for me. ;)

Re: Im dumb, Help me with my wideband question and I'll give you a discount!
 

make a X | Y table

EX:
X | Y
0 | 0
1 | 4
2 | 8

x=4y, or 1v = 4a (in this example)

dunno if that example was real or not. i got the table so i get points right? i gotta get back to work so i'll check back afterwords and get shopping ;)

Re: Im dumb, Help me with my wideband question and I'll give you a discount!
 

http://www.fourgasmmotorsports.com/AFR-VOLTS.xls

Re: Im dumb, Help me with my wideband question and I'll give you a discount!
 

Use the proportion formula.

X1=Y1*X2/Y1

example: X=3.78*22.39/5

X=16.93

The following is true only when using Innovate's factory settings.

Where R=Reading in Volts and X= measured A/F

X=(R*3.008)+7.35

Example: R=2.45

X=(2.45*3.008)+7.35

X=14.72

This should provide you with the values you are seeking. Good luck! ;D And where's my discount >:D ;D

Re: Im dumb, Help me with my wideband question and I'll give you a discount!
 

this might be a retarded question, but why not just program the LM-1 to output .8 to .22 volts

where
.8v = 8:1
.147 = 14.7:1
.22 = 22:1

Re: Im dumb, Help me with my wideband question and I'll give you a discount!
 

Yes you can program its output to any 0-5v voltage range...linear.

So you can use the slope/line formulas.

Y =mX + B
where M is the slope and B is the Y intercept

m = (Y2 - Y1)/(X2 - X1)

Remember 10th grade ;D

So if you make .5v = .5 lambda and 4.5v = 1.5 lambda...what voltage is 1 lambda (14.7 AFRs)?

m = (4.5 - .5) / (1.5 - .5)
slope = 4

b = Y - mX
b = 4.5 - 4(1.5)
b = -1.5

Y = 4(1) - 1.5
Y = 2.5

So at approx 2.5v you will have 1 lambda or 14.7

I think I'm thinking straight today :P

Re: Im dumb, Help me with my wideband question and I'll give you a discount!
 

I am totally lost lol....I never do math......I'm really just looking to use a "function" in excel so it will do all the conversions for me.....kinda like =(a1*b7)....That will return a value in excel, is there a way to do that with this?

Re: Im dumb, Help me with my wideband question and I'll give you a discount!
 

damn u guys are smart!