What am I missing? LTFT/VE tuning.
What am I missing? LTFT/VE tuning. So, I've been scanning/tuning with Flashscan 7.3 and my car seems to be getting quite a bit better. A lot of the cells at the lower right hand (higher rpms, higher MAP) are getting in the -2 to -4 range for average LTFT. I am still having problems with the cells down low, though.
I have gone through several cycles of many of the cells being in the +15% range, and I feel like I have increased VE substantially (increase is the right direction, correct???) I really have a mild turbo cam (so mild that you can barely hear it at idle with no cats) and have fairly mild/dated WCCH 72cc LS1 heads. Some of these cells have probably gone up at least 40% with the number of times I've tweaked them. Can that be right? Do even mild cams and mild heads let that much more air in the cylinders? I realize you'd need some specs on the cam to make a more accurate judgment but it just feels like something is off base.
Odd, too -- when I get into the cells that are still dumping +15% through LTFTs, I start to notice smoke out the tail pipes. Unburnt fuel perhaps? The motor and clutch are new and have 200 miles on them so possibly still a ring seating issue, I dunno. But is editing VE alone by logging lots of LTFT the best way to proceed?
I have gone through several cycles of many of the cells being in the +15% range, and I feel like I have increased VE substantially (increase is the right direction, correct???) I really have a mild turbo cam (so mild that you can barely hear it at idle with no cats) and have fairly mild/dated WCCH 72cc LS1 heads. Some of these cells have probably gone up at least 40% with the number of times I've tweaked them. Can that be right? Do even mild cams and mild heads let that much more air in the cylinders? I realize you'd need some specs on the cam to make a more accurate judgment but it just feels like something is off base.
Odd, too -- when I get into the cells that are still dumping +15% through LTFTs, I start to notice smoke out the tail pipes. Unburnt fuel perhaps? The motor and clutch are new and have 200 miles on them so possibly still a ring seating issue, I dunno. But is editing VE alone by logging lots of LTFT the best way to proceed?
I don't know exactly what lower cells you are referring to, but the low speed and idle cells seem to step on top of each other pretty good in my car. I can typically tune for one or the other (idle or low speed) but not both.
I figured it's not something to pull my hair out over. I let the idle trims run a little high (+5-8 LTFT) knowing that my low speed trims are good (0 to -4/5). I guess I could redistribute the airflow zones, but figured it's more trouble than it's worth..at least for me.
Also if you still have a MAF it can affect fueling, even at idle.
I figured it's not something to pull my hair out over. I let the idle trims run a little high (+5-8 LTFT) knowing that my low speed trims are good (0 to -4/5). I guess I could redistribute the airflow zones, but figured it's more trouble than it's worth..at least for me.
Also if you still have a MAF it can affect fueling, even at idle.
muncie... THANK YOU. That is exactly what I was looking for. From what I was seeing I could only speculate that there were multiple tables affecting low speed/idle conditions, and you just confirmed it.
I'm getting ready to install my LC1 now, should only be an hour away from doing some AutoVE. We'll see where that leads me.
I'm getting ready to install my LC1 now, should only be an hour away from doing some AutoVE. We'll see where that leads me.
