Table switching to increase VE and spark resolution for MS2
03-15-2011, 03:41 PM
#21
2 Props,3 Dildos,& 1 Cat
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So what rpm break points are you guys using from idle to 2k rpm if you don't have MS3 resolution for VE and spark?
I've noticed that having a large area around idle (up to 1400rpm) that maintains my idle advance (14 degrees) My idle settles very quickly at various humidity, temp, etc conditions. However, notice a significant off idle power reduction by removing this much timing.
I've noticed that having a large area around idle (up to 1400rpm) that maintains my idle advance (14 degrees) My idle settles very quickly at various humidity, temp, etc conditions. However, notice a significant off idle power reduction by removing this much timing.
500, 800, 1250, 1800 RPM
10, 24, 35, 55 kPa
I am of the school of thought that you want to "trap your idle" between breakpoints, not let it sit on one.
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03-15-2011, 03:54 PM
#22
would it blow your mind if I said you could have a second idle VE table that is used for certain circumstances?
I have no idea what KPA and rpm you would be running in 5th gear at 25mph. I'm going to assume something very closed to idle rpm
I am of the school of thought that you want to "trap your idle" between breakpoints, not let it sit on one.
Mine is trapped between 700 and 1100. 700 rpm is my lowest cell
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03-15-2011, 07:22 PM
#23
I'm using table switching at 100kpa set up so the off boost map has better resolution at low/cruise rpms and the on boost map has better resolution from just shy of torque peak onwards.
I can attest that the extra resolution makes using VE analyzer hectic. I have to manually smooth the cells that dont get touched, only to have them changed later by ve analyzer. The extra cells aren't helping me any as the changes are linear enough for interpolation to easily handle. If i got the gumption, i'd just rescale VE table 1 to handle everything. I'm betting that it would only be beneficial with a 4 bar map and the boost to use it all
I left this page open for a while and didnt refresh before posting. Using table 1 as an idle table doesnt seem like a bad idea. I may have to try this
I can attest that the extra resolution makes using VE analyzer hectic. I have to manually smooth the cells that dont get touched, only to have them changed later by ve analyzer. The extra cells aren't helping me any as the changes are linear enough for interpolation to easily handle. If i got the gumption, i'd just rescale VE table 1 to handle everything. I'm betting that it would only be beneficial with a 4 bar map and the boost to use it all
I left this page open for a while and didnt refresh before posting. Using table 1 as an idle table doesnt seem like a bad idea. I may have to try this
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03-15-2011, 08:00 PM
#24
I'm using table switching at 100kpa set up so the off boost map has better resolution at low/cruise rpms and the on boost map has better resolution from just shy of torque peak onwards.
I can attest that the extra resolution makes using VE analyzer hectic. I have to manually smooth the cells that dont get touched, only to have them changed later by ve analyzer. The extra cells aren't helping me any as the changes are linear enough for interpolation to easily handle. If i got the gumption, i'd just rescale VE table 1 to handle everything. I'm betting that it would only be beneficial with a 4 bar map and the boost to use it all
I left this page open for a while and didnt refresh before posting. Using table 1 as an idle table doesnt seem like a bad idea. I may have to try this
I can attest that the extra resolution makes using VE analyzer hectic. I have to manually smooth the cells that dont get touched, only to have them changed later by ve analyzer. The extra cells aren't helping me any as the changes are linear enough for interpolation to easily handle. If i got the gumption, i'd just rescale VE table 1 to handle everything. I'm betting that it would only be beneficial with a 4 bar map and the boost to use it all
I left this page open for a while and didnt refresh before posting. Using table 1 as an idle table doesnt seem like a bad idea. I may have to try this
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03-15-2011, 10:24 PM
#27
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I thought I was clear above with the 25mph in 5th gear...
idle load and rpm is a pretty small region of operation, right?
normal (or abnormal) driving can occur in the cells also used for tuning idle in theory.
you may also want to tune the initial fuel delivery for idle cells to be slightly richer to prevent stalling but once things settle down, you want to go back to closer to 14.7 AFR.
I use it mainly to avoid autotuning those cells incorrectly. the idle ve table provides a "dont touch me" table.
would it blow your mind if I said you could have a second idle VE table that is used for certain circumstances?
idle load and rpm is a pretty small region of operation, right?
normal (or abnormal) driving can occur in the cells also used for tuning idle in theory.
you may also want to tune the initial fuel delivery for idle cells to be slightly richer to prevent stalling but once things settle down, you want to go back to closer to 14.7 AFR.
I use it mainly to avoid autotuning those cells incorrectly. the idle ve table provides a "dont touch me" table.
would it blow your mind if I said you could have a second idle VE table that is used for certain circumstances?
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03-15-2011, 10:32 PM
#28
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I think the benefit would be in overall drivability and those not so often used cells. A drag car obviously doesn't need as much resolution as a road racer, or a street car. I would like to have a few more lines of cells around cruise. for the most part it would just be more to tinker with as stated above, which I enjoy. it would be another cool thing to play with. and I pose the question; if more resolution isn't any better, then why all the hype about switching to highres firmware and why not just have 8x8 tables.
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03-15-2011, 10:35 PM
#29
I really like the idea and I'm interested to know how it works out. As I increase boost I find myself "stealing" cells from lower KPA. I'd certainly like to have a little of that back, whether it's absolutely necessary or not. I've also found that when I'm tuning the car I'm usually either focusing on WOT pulls or cruise so I don't think the tuning aspect would affect me significantly.
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03-16-2011, 08:56 AM
#30
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So you tune your regular table for transients, i.e. entering idle. And there is a lag before it "enters idle", and then it uses the "idle maps". Correct? Sounds like a good workaround for solving certain issues, and FWIW a more "elegant" solution might be to recognize and address the transient to begin with.
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