"IF" statements in histograms???

[kennyspec]

Is it possible to use a "IF" statement in a histogram?? if not in a histogram can i use a "IF" in setting up a custom [PID]??
what i am trying to accomplish is a histo. that will advance my timing
by1* "IF" no knock is detected.

thinking back to a IF statement in a EXCEL spreadsheet it would be something like.....

IF([SENS.TIMING RETARD] = 0, [SENS.TIMING ADVANCE]+1 , [SENS.TIMING ADVANCE] - [SENS.TIMING RETARD])

so what im trying to say is if i have no knock in a cell advance timing by 1. if there is knock in that cell minus that amount of kock.


or i guess i could only make the values display when
[SENS.TIMING RETARD]=0

and then in the cells that do not display i have knock. i would then use my timing retard histo. to minus knock in those cells????


i hope this makes sense. i just thought this would be the easiest way to advance timing in every possible cell without getting knock.

[jimmyblue]

Why not add (1-KR)? Then it will also pull back timing if
more than 2 degrees.

[EC_Tune]

You can't add or subtract timing with histograms. Only log what the timing currently is or how much timing is being subtracted due to KR.

This sounds like a feature request but since we have RTT, you can use that to change advance on the fly (LS1 series only).

[Bill@HPTuners]

if Possible I think its a great idea...I was actually trying to do this the other day but had 0 success...

[kennyspec]

[QUOTE=EC_Tune]You can't add or subtract timing with histograms. Only log what the timing currently is or how much timing is being subtracted due to KR.
QUOTE]


i set up a custom pid to log [SENS.TIMING ADVANCE]+1 and then i use that pid in my histogram. after driving around town i now have a timing map that has 1 degree advancemnt. i then copy this map into my tune. then i subtract all the cells that have knock in them from my timing retard histo. basically i can do what i want now. but the IF statements would make it a whole lot quicker.

[Bill@HPTuners]

problem is gm looses about 1* of timing during scanner translation so what your seeing in the scanner might be .5 or .75 less or more than your actual timing table...then add in the knock learn factor, idle timing, etc & iat adders & you'll run into all kinda issues trying to do it like that...just my .02

[kennyspec]

well the car is a 06 cobalt SC and i am running it in SD with all the timing and AFR multipliers set to 1 and all the timing adders set to 0. It seems like in the scanner i am getting what my timing map is set to. i am just more concerned wih tuning WOT timing as this is my "track tune" only.

[Bill@HPTuners]

Yeah I understand...im just telling you the conclusions that I've come to in the little testing I've done...you've obviously done your homework & seem to be on the right track so I'll leave you to your work...If I can lend you any assistance let me know.

[5_Liter_Eater]

i set up a custom pid to log [SENS.TIMING ADVANCE]+1 and then i use that pid in my histogram. after driving around town i now have a timing map that has 1 degree advancemnt. i then copy this map into my tune. then i subtract all the cells that have knock in them from my timing retard histo. basically i can do what i want now. but the IF statements would make it a whole lot quicker.

That's pretty neat! So you end up adding timing to any cell you logged data to that didn't have KR; actually you add 1 degree to the cells regardless and then subtract the KR. Are you only doing this to WOT runs or just normal driving?

[kennyspec]

i am adding timing to every cell in WOT and normal driving. But i mainly wanted to set this up for WOT tuning.

[EC_Tune]

Hmm. I have found that best timing isn't necessarily timing that is close to KR. Sometimes yes but a majority of the time it's finding the AFR that works best and moving the spark down to fit. More power, less fuel, less timing, better efficiency.

[kennyspec]

very interesting EC Tune. Do you mind sharing how you find the best AF ratio?? just countless hours on the dyno?? should i just shoot for one AF ratio throughout the entire RPM range or is it more benefical to have it get leaner/righer after max torque in the powerband??

[EC_Tune]

Well, maybe not countless hours. But a dyno does help.
However you can do a 3rd gear pull from say 2000 RPM to redline & log the time differential. Make changes and do the same log again and see if your time increases or decreases. If it increases, you went backwards...

*Generally* supercharged motors make best power at about 12.0 AFR if you are in the 7+ PSI range. If you have 2-5 PSI I might bump the AFR up to ~12.5-12.2 for the PSI range.