Datalogging a/f with SCT and WBC

[Hawgman]

Has anyone set up their WBC to where you can datalog your a/f ratio with Live Link 3 and the XCal II? I know the WBC has analog ports on it and supposedly it can be done with some splice work on the cable from the XCal II. But haven't been able to locate a wire diagram yet to tell me what wires I need to splice.

 

[Kevin@PMP]

You need a 9 pin DIN cable (available from SCT) splice the analog output wire into the analog 1 or 2 wire on the 9 pin DIN cable. Plug into the XCal, open live link select analog 1 or 2 as a parameter to datalog and proceed as normal.

If you want to have LL show the AFR instead of the voltage you will need to right click on the Analog signal in the datalogging window and configure it to calculate AFR based on voltage to match the output of your WBC. So if your WBC outputs 10-20:1 your formula would be (v*2)+10. To figure out your formula take the range for your WB and divide by 5 (see edit below) (in this case 20-10=10, 10/5=2) this means for every 1 volt = 2afr. Now since we have a starting point of 10:1 (or whatever the case may be) at 0v you have to add that to the formula.

So at 1v which should be 12:1 in this scenario you have (1v*2)+10=12

I hope that makes sense, it does to me but I have done it way too much.

Edit example formulas:

8-16:1 (v*1.6)+8

9-14:1 (v*1)+9

Edit: The reason you divide by 5 is a wideband outputs over a 0-5v range.

 

[Hawgman]

Kewl, thanks Kevin.
Right now I am having to run the LL3 and the WBC software simultaneously. Big enough pain in the ass to keep up with one piece of software while driving, much less two.

 

[Kevin@PMP]

No problem, let me know if you have any questions.

FYI for those that don't know and are considering a wideband, if you want to get serious and do a lot of datalogging make sure you but a WB with a linear output i.e. DynoJet WBC or Innovate LC-1. The AEM and some others have a non-linear curve and LiveLink cannot calculate anything other than a linear curve. So you are stuck doing a best fit formula.

 

[Redfire]

Kevin you gave me a headache with all of those formulas.

If you are using the WBC the formula is 1.6*V+10

 

[Kevin@PMP]

Kevin you gave me a headache with all of those formulas.

If you are using the WBC the formula is 1.6*V+10

LOL I couldn't remember what the WBC uses it obviously has a 10-18:1 resolution. That's one reason I like the LC-1 I can program the output to give me more resolution over a narrow range say 10-13:1 so it's a little easier to notice incremental changes.