TT_Vert

iTrader: (12)

I did two back to back runs. One w/ no PE mods and one w/ 102% PE. My ltrims on the first run w/ no PE mods was 0 at WOT, on the 102%PE run it was +.8 on both banks. I didnt realize it had this effect. Does this mean for my PE mods to be of any use on back to back track runs I should reset my Ltrims before every PE change?

What do you guys do who use the track to tune?
Thanks
dave

jimmyblue

iTrader: (11)

I've seen PE changes (on Predator) push LTFTs around.
But, enriching should have pushed you negative, not
positive. It seems more likely to me that you "left from"
a cell that had positive trims on the second pass.
Review the logs for LTFTs and see if this is true, if
you have some cell that is not < 0.0 - and whether
this "came on" following the PE change, of was there
in the previous but you just didn't "step in it".

TT_Vert

iTrader: (12)

you might be right but thats odd because usually all of my Ltrims are -3 or so.
Perhaps its just one of those oddities.

Dave

Another_User

I was noticing the same thing the other day. I also noticed that when you tinker with the PE TPS kick-in percent you run richer. I have a feeling that a lot of the older ways of tuning are not the most efficient.

deezel

Also note that no learn time can result in funny LTrims. +0.8% with no learn time is meaningless. Remember the basics... 50+ miles of drive time to learn fuel trims before making any tuning decisions (based on fuel trims).
Your PE changes, however, take effect immediately after a flash.