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Re: Sc14 to buick and e85
Posted: Tue Oct 07, 2014 7:54 pm
by TdracerTd
As holden202t says, I just want the targets to display in lambda and the logs to read in lambda. I thought it would just be a matter of logging the wideband in lambda and then adjusting the a/f target tables to match. Same as what I did to convert my tables to e85 Afrs.
Am I missing something?
Also vl, can you explain the equation you gave me for the wideband logging. I think I understand you are setting the range with (1.52-0.5). "X" is the data coming in from the sensor? I just don't understand why it's divided by 256? I mean I get it, but where does that number come from?
Is there some reading that I can do that will help me get my head around it? Something like "an idiots guide to the 808 and $12p" haha

Re: Sc14 to buick and e85
Posted: Wed Oct 08, 2014 3:14 am
by TdracerTd
Okay! I'm not sure if I've been thinking about this because of tonight's insomnia or if tonights insomnia is caused by me thinking about this, but, I think i get it.
If the 0v wide band is set to 0 and the 5v wideband is set to 25.5 then when the wideband signal Is 2.5v (stoich) x will be 12.7.
((1.52-0.5)*(12.7/256))+0.5 = 0.1 then if stoich value = 14.7 so 147 * 0.1= 14.7. If stoich was set to 1(lambda) then 0.1 * 10= 1????
Just not sure about the bit where the stoich value is * 10. why is that?
I see by setting the 0v and 5v wideband at their limits it gives us maximum resolution on the sensor input to the ecu. This was baking my noodle for a bit.

Re: Sc14 to buick and e85
Posted: Wed Oct 08, 2014 11:28 am
by VL400
TdracerTd wrote:If the 0v wide band is set to 0 and the 5v wideband is set to 25.5 then when the wideband signal Is 2.5v (stoich) x will be 12.7.
X at this point will be 127. The 256 comes from the 8bit analog to digital conversion, there are 256 steps (0-255 counts) over 0-5V.
TdracerTd wrote:((1.52-0.5)*(12.7/256))+0.5 = 0.1 then if stoich value = 14.7 so 147 * 0.1= 14.7. If stoich was set to 1(lambda) then 0.1 * 10= 1????
With the X being out by a factor of 10, it would be .. ((1.52-0.5)*(127/256))+0.5 = 1.00
So at stoich of 12.7 AFR lambda is 1.00, as you would expect.
TdracerTd wrote:Just not sure about the bit where the stoich value is * 10. why is that?
The Stoich * 10 is for the XDF tables. As an example, the target AFR table will currently have X / 10 or X * 0.1 as the calculation (gives exactly the same result). With say 12.7 AFR displayed by TunerPro the raw data stored in the ECU will be 127.
So to display lambda, the raw data in the table will still be 127 and we want that to display lambda of 1.00 with a stoich if 12.7. So the calc is X / 127. With 127 being Stoich * 10. The ECU uses AFR * 10 for all its internal calcs.
TdracerTd wrote:I see by setting the 0v and 5v wideband at their limits it gives us maximum resolution on the sensor input to the ecu. This was baking my noodle for a bit.

Correct, the ECU code is setup to work with a larger range than lambda so its not ideal. The settings of 0 and 25.5 so that the ECU does not modify the raw analog value when trying to work out AFR. Instead it lets TunerPro do the calculation. Note, this means that VE learn will not work!
Re: Sc14 to buick and e85
Posted: Wed Oct 08, 2014 7:47 pm
by TdracerTd
Aha! Thanks VL. All clicking into place

Re: Sc14 to buick and e85
Posted: Tue Nov 04, 2014 11:53 am
by TdracerTd
Can anyone tell me how I would know how much AE is altering the injector BPW? I would like to have it show on my dashboard in tunerpro. Can't work out which gauge to add.
Re: Sc14 to buick and e85
Posted: Tue Nov 04, 2014 1:11 pm
by VL400
It normally happens too quickly to see when logging, the AE fuel pulses are not added to the fuel PW in ms that you log. They occur between normal injection events, there is a AE PW term in 12P but it rarely changes due to logging happening comparatively slowly compared to fuel injection events. The AE PW term gets a calculated value written to it, the ECU delivers the fuel and it goes back to 0 once done.
Re: Sc14 to buick and e85
Posted: Tue Nov 04, 2014 1:13 pm
by Holden202T
what about message 6, log just map, rpm, and AE or something like that, will it be quick enough to pick up at all ?
Re: Sc14 to buick and e85
Posted: Tue Nov 04, 2014 1:16 pm
by VL400
If you can log at 33Hz that gives one frame per rev at 2000RPM, so might get something then. It does decay so may not see the full amount if you catch it half way through delivery.
Re: Sc14 to buick and e85
Posted: Tue Nov 04, 2014 1:29 pm
by TdracerTd
What about a flag to let me know when AE is in effect? About to do some dyno tuning. I had some schooling with a friend of mine who uses kalmaker. On the Kalmaker dash, there is a an indicator that tells him when AE and DE are acting. How does everyone do this with tunerpro?
Re: Sc14 to buick and e85
Posted: Tue Nov 04, 2014 1:47 pm
by Holden202T
if you are dyno tuning then I'd say get the VE table right without AE and then if you have a spike its from AE and you can tune that properly afterwards....