negative advance question

[Seb Cyclefer]

Re: negative advance question

Thanks all for your replies.

I've already have the 2.1.16 new release but it doesn't change anything from the 2.1.14. It is probably a 1997 bug.

Here is 2 of my timing advance histogram, one with the min values and the other with the max values.

According to ssms5411, the min setting will tell you your max timing. So in my screenshots, at 4000 rpm and 0.56 g/cyl, I have -20 in my min setting and -16 in my max setting. Does it mean that the true value in the min setting for that cell is 16 and the true value in the max setting is 20 ? Or maybe must I just take the absolute number for example -20 will become 20 ?

Thanks

[slow6]

Re: negative advance question

haha that sux
sorry for you
its a little confusing eh?

16 is min
20 is max
18 is average

[Seb Cyclefer]

Re: negative advance question

16 is min
20 is max
18 is average

Thanks. So, if a have a positive value, that's a negative one, right ?

[97rs4life]

Re: negative timing advance question

I know along time ago I ask Hptuners if they could fix the error and they said the would have to redue the whole programming and it wouldn't be worth the time and efffort just to fix this one problem, so I think they came out where you can change something in the PId to correct it. As long as I can tune and still read the scanner I don't care about the - in front of the #.

Any more info on what needs to be changed? I would like to actually see positive instead of negs for my advance. A bit less confusing

[iGoRa]

Re: negative timing advance question

you would have to create custom PID , If anyone else would be using it , I can look into it

[iGoRa]

Re: negative timing advance question

Solution 1
Create a user defined PID and insert into the table as follows:
Name: Timing Advance - V6 Fix
Abbrv: Adv - V6
Sensor: Timing Advance
Units: °
Function: -3.0 * [PID.14]
How it works: The scanner will average the values of all sensors of same type currently being scanned. What we have done here is create a new PID that returns 3x the spark advance in the positive direction so that when it averages the two values you get the actual spark advance in the positive. You shouldn't have to change your histograms, charts, gauges etc. as they all log as sensor based by default.

Solution 2
This method is similar but uses -1.0 * [PID.14] as the function. You would then have to go switch your histo's and charts etc. to plot the PID value rather than the sensor value.

byHPT

[97rs4life]

Re: negative timing advance question

Thanks IGoRa for that info. Going to have to try it this spring when the car is out of storage

[foff667]

Re: negative timing advance question

What IGora posted is right in the help file guys...its a very good read ;)

Basically all 97's are like this...even 96-97 LT1 cars spit out a negative number rather then positive. Its a GM bug not an HPT bug...but if it bothers you just use the formula and it changes it to a positive number for ya.