Stomp Compensation and Impact Factor, whats the difference?????

[BlackGMC]

Alright just wondering if someone could shed some light on the differences between these two tables... I have an 04 GMC Sierra and the transient/dynamics tables are completely different than the standard LS1 tables... They are kinda useless IMO, they are all coolant temp and Ethanol percentage based tables... The LS1s are at least MAP based...

[mr.prick]

I too have been trying to change these tables.
I think that both the impact fact and evaporation time need
to be changed at the same time to have an effect.
:nixweiss:

Here is a discussion on the dynamics tables from another forum.
Let's discuss Transient Fuel
(http://www.hptuners.com/forum/showthread.php?t=10872&highlight=Enrichment+Accel+Acceleration)

[BlackGMC]

Interesting.... I checked out that link and some things started to make sense... From my experiments yesterday this is what i discovered....

Impact Factor - When i increased this, it seemed to help with the lean Tip-In. Meaning when i went WOT, the AFr got to the commanded AFR quicker.... So it increased the amount of Air coming in at one shot.

Evaporation Time - When i increased this, it seemed to increase the duration of the Impact Factor.. When i increased the Impact factor without increasing the evaporation time, the AFR i would get to the commanded but quickly go lean after the initial shot... Increasing the Evaporation time would keep it at the commanded...

From that link the Stomp seems to be for warmup cycle, which makes sense. Yesterday when i first start logging after to flashing in a new tune it would be lean for about 4-5mins, i thought it was just my Wideband coming up to temp...


I will try messing with some of these again, now that i have a little better understanding...

[Chevy366]

I too have been trying to change these tables.
I think that both the impact fact and evaporation time need
to be changed at the same time to have an effect.
:nixweiss:

Here is a discussion on the dynamics tables from another forum.
Let's discuss Transient Fuel
(http://www.hptuners.com/forum/showthread.php?t=10872&highlight=Enrichment+Accel+Acceleration)
I agree , I tried changing all 4 parameters by +10% and @ slightly below operating temperature to above OT , saw a slight difference .

[mr.prick]

I think the evap time needs to be higher when rich and lower when lean.
I have a thread asking which tables to change and how to do it but nothing became of it.

[BlackGMC]

I looked at a couple more of my logs from yesterday in regards to the Stomp setting...


Something i noticed yesterday that on initial startup the AFR would be lean (avg BEN 1.05) on a freshly tuned VE table, this leanness would last ~ 30-45secs... I increased the Stomp factor (actually thinking it did something else) and the next log the initial AFR was leaner (avg BEN 1.08)... Granted i am not sure the start times on the log, some might have been imediately after startup some might be a few seconds after starting... The difference between those 2 logs was an increase in the Stomp settings... The increase was 5%... So it seems to get the AFR/BENs inline during the warmup cycle i actually needed to decrease the Stomp settings....

It is making more sense now... I will do some more experiments tonight...

[BlackGMC]

Ok i did a little more messing around with the IMPACT FACTOR. The first screen shot is stock settings, notice the AFR i selected and also notice the rich tip out....

http://i27.photobucket.com/albums/c185/BlackGMC/Truck/Tuning/StockImpactFactor.jpg


Next i increased the IMPACT Factor WOT by 25% and decreased the IMPACT FACTOR closed Throttle by 15%. Notice the selected AFR and also the rich tipout...


http://i27.photobucket.com/albums/c185/BlackGMC/Truck/Tuning/StockImpactFactor_0002.jpg


From the logs looks like I should have decreased the stock IMPACT FACTOR WOT settings and decreased the IMPACT FACTOR Closed Throttle by another 15%... One thing i noticed while driving the second tune around, the throttle response was less, the truck felt sluggish...


I will mess with this some more tomorrow.

[BlackGMC]

Here are some more logs,

This one i decreased IMPACT FACTOR WOT to 25% less than stock and I decreased the IMPACT FACTOR Closed Throttle by 15%... It seems to help with the AFR not going as rich..

http://i27.photobucket.com/albums/c185/BlackGMC/Truck/Tuning/StockImpactFactor_0003.jpg

Ok next i decreased the IMPACT Factor WOT again by 25% and this time increased the Evaporation time by 50%

http://i27.photobucket.com/albums/c185/BlackGMC/Truck/Tuning/StockImpactFactor_0004.jpg

It seems like it is getting closer...

[BlackGMC]

Ok, last round for the night, again i decreased the IMPACT Factor and increased the evaporative time....

http://i27.photobucket.com/albums/c185/BlackGMC/Truck/Tuning/StockImpactFactor_0005.jpg


Ok, now it seems that I went a little to far, i decreased the IMPACT factor and increased the Evaporative time... Seems like i need to add a little back tot he impact factor and increase the evaporative time again...

http://i27.photobucket.com/albums/c185/BlackGMC/Truck/Tuning/StockImpactFactor_0006.jpg

[hquick]

I found Impact Factor Modifier had most/best effect at combatting lean tip in's.

[Chevy366]

Hmmm , good logging diagnostics .
You are doing this on a COS3 right , not MAF ?

[mr.prick]

I found Impact Factor Modifier had most/best effect at combatting lean tip in's.

The lean tip is no big deal to me,
it only happens when the throttle is mashed hard and it is not too severe.
The throttle slam over rich condition is what I would like to stop.

[BlackGMC]

Hmmm , good logging diagnostics .
You are doing this on a COS3 right , not MAF ?

Yep COS3 no MAF yet. Eventually i will turn it back on...

[Mr. P.]

...The throttle slam over rich condition is what I would like to stop.
Well then, don't lift your foot off the gas :laugh:

Mr. P. :)