Cylinder skew help UPDATED! VERY SERIOUS!

[Quick6]

The default is set to 1.0 accross the board. If i change it to 1.2 does that mean i just added 20% or 2% to that cylinder compared to the rest?
Thanks

[Overclock_This]

How did you get Cylinder Skew to work for V6's?
I can't edit Cylinder Skew

The default is set to 1.0 accross the board. If i change it to 1.2 does that mean i just added 20% or 2% to that cylinder compared to the rest?
Thanks

[Bill@HPTuners]

...

[Chris@HPTuners]

the help files had a slight bug in the 1.6.0 release. The skew numbers actually multiply the calculated Injector Pulse Width for that cylinder (i think the help files said Injector Flow rate). Numbers higher than 1.0 mean more fuel, less than 1.0 mean less.

[Quick6]

Chris,
The numbering system you used correspond with actual cylinder number or firing order position?
Have you physically verified that changing cyl#1 does change inj#1?

Last question, say i wanted to richen one cylinder 2%, what would the formula be awith correct answer?
Thanks

[johnt]

The numbering system you used correspond with actual cylinder number or firing order position?
Have you physically verified that changing cyl#1 does change inj#1?

Excellent question, I was wondering that myself.

Last question, say i wanted to richen one cylinder 2%, what would the formula be awith correct answer?

Rob, why wouldn't you just put a 1.02 in the appropriate entry? What do you have in mind?

John

[Quick6]

Hi John,

I'm feeling math challenged tonight. ;D Chris said it multiplied the inj pw, so say i want to richen a cyl 2.5%, what base do i use? The max pw the pcm is showing under wot? Do i add 2.5% to say 18mS P/W? See what i'm saying?

[johnt]

I'm sorry Rob, I'm not following you. ??? The injector skew table entries are multipliers for the injector pulse widths. If you want one injector to have 2.5% more fuel than the others, you set the entry for that cylinder to 1.025, while leaving the others at 1.0000. The PCM will automatically calculate the new IPW for that cylinder using the 1.025 multiplier. The IPW for that cylinder will then always be 2.5% more than the others, until it goes static of course. It's not a fixed IPW adder, it's a multiplier for all values of IPW. Am I still missing your question?

John

[Bill@HPTuners]

the help files had a slight bug in the 1.6.0 release. The skew numbers actually multiply the calculated Injector Pulse Width for that cylinder (i think the help files said Injector Flow rate). Numbers higher than 1.0 mean more fuel, less than 1.0 mean less.

thanks for clearing that up.

[Overclock_This]

I have no access to Skew vs. Cylinder table.
It's shaded out.
Am I supposed to be able to edit that table?
I assumed V6's can't edit that table.

[Quick6]

Skew table is WRONG!!!!!! Checked mine today and here is what i found.

Eng cyl# Software cyl#

#1 ---------------- #3

#2 ---------------- #2

#3 ---------------- #1

#4 ---------------- #6

#5 ---------------- #5

#6 ---------------- #4

Your welcome

[arthansen]

I can change values in the table so it does work in some V6s.


Quick6, is the software cylinder number wrong in both the scanner and the editor? If it is wrong in just one it would explain why I could not get the results I wanted as I tried to balance the injectors.

[Quick6]

I just checked my plugs after 100miles, the 3 cylinders i richened are actually running LEANER than the rest!! So until we get this figured out, beware and use at your own risk.

[wait4me]

i found this also, so i have been puting "90" in the tables i wanted to richen. and it gets better.

[Quick6]

Well after more testing, i put bank1 at 1.20 and saw the increase in PW for those injectors. 0 kills them. So the multiplier seems correct.

[Chris@HPTuners]

ok guys, i finally worked this one out

The cylinder number refernces the firing order sequence, but the weird thing is the mapping.

in the current editor:
editor #1 = cyl5 in firing order = actual #3
editor #2 = cyl6 in firing order = actual #2
editor #3 = cyl1 in firing order = actual #1
editor #4 = cyl2 in firing order = actual #6
editor #5 = cyl3 in firing order = actual #5
editor #6 = cyl4 in firing order = actual #4

firing order being: 165432

which matches what Quick6 posted.

I'm going to update the editor to reflect the actual # as i don't see any inconsistencies across calibrations. Please let me know if your vehicle is seeing a different mapping and i will investigate further.

Chris...

[Quick6]

Thanks Chris! Make sure we know when you do it so i can change my program

[pknowles]

Is the cyl swew only a V6 option? I can't find it anywhere for my V8.

[pknowles]

Is the cyl swew only a V6 option? I can't find it anywhere for my V8.

Nevermind, looked in the help file and saw it's only for V6.

[Chris@HPTuners]

yeah, the V8 doesn't have this option in the code.