explain timing percents

[puller24]

I need someone to explain how much timing the adjustments will add. for example if i add "+5" in the predator, how much timing advance would that equal? It seems as though the PCM still controls spark but you're just adding on to whatever the pcm decides. How much does adding/subtracting fuel affect the actual ratio. Im trying to save time when my wideband gets here.

[Phil]

Puller24, It will tell you right on the scale where you make the adjustments if it is in degrees or percentages. If it says degrees the changes are in 1 degree increments. If it gives you a scale up to 20 - 25 % those changes are made by a percent value.

[Shaken]

I need someone to explain how much timing the adjustments will add. for example if i add "+5" in the predator, how much timing advance would that equal? It seems as though the PCM still controls spark but you're just adding on to whatever the pcm decides. How much does adding/subtracting fuel affect the actual ratio. Im trying to save time when my wideband gets here.

To get the answer you would have to data log the ignition timing of your vehicle. I.E. highest timing x .05 = degrees of advance or retard. As far as fuel start with the canned tune or factory tune and get it around 12.5 -13.0 to 1 N/A. If n2o or forced induction I believe 11.8 is a good number from reading other forums or post.

[puller24]

Example: I have 18° at 2500RPMs, 21° at 3400, and finally 26° at 6000 RPMs. So in this particular log, if i had the timing advance "5%" (or +5 on the slider scale) from 2k-7k RPMs, then I really only advanced it 1.3°?? so the stock timing would be 24.7° at 6000 RPMs? thanks

[Shaken]

Example: I have 18° at 2500RPMs, 21° at 3400, and finally 26° at 6000 RPMs. So in this particular log, if i had the timing advance "5%" (or +5 on the slider scale) from 2k-7k RPMs, then I really only advanced it 1.3°?? so the stock timing would be 24.7° at 6000 RPMs? thanks

.9@ 2500 1.05@3400 1.3@6000 From what I understand the percentage in determined from the total timing at any given rpm. So my car has 10 degrees initial for example using your figures 18 @ 2500 the computer added 8 degrees to the 10 to get 18 now add .9 you added with your Predator 18.9 and so on. 21+1.05=22.05 26+1.3=27.3 . The real gains I believe come from getting you air fuel ratio correct. If anybody has any better information please chime in

[bandersson]

I believe it is displaying degrees, not percent. So if you set it to +5 that would mean you advanced the timing by 5°, not 5%.

[Shaken]

For the U7146 it is in percentages for which I was showing examples. Phil's previous post explained Phil

PostPosted: Feb 13, 2008 - 11:37 AM
Puller24, It will tell you right on the scale where you make the adjustments if it is in degrees or percentages. If it says degrees the changes are in 1 degree increments. If it gives you a scale up to 20 - 25 % those changes are made by a percent value.

Not knowing which tool he has and the other method is simpler I went on to explain the percentage value. I tell you it would be alot easier if it was in degrees.