Table switching to increase VE and spark resolution for MS2
#1
Table switching to increase VE and spark resolution for MS2
Anyone out there try using fuel/spark table 1 as an idle only table, then use table 3 as the main fuel/spark table.
Set the table switch to something like TPS > .5%
It should allow a couple more rows of resolution for the normal tune for table 3, and a huge idle area for table1
Set the table switch to something like TPS > .5%
It should allow a couple more rows of resolution for the normal tune for table 3, and a huge idle area for table1
Last edited by miatauser884; 03-14-2011 at 07:08 PM.
#3
As long as the latency for table switching is short. You should be able to have a high res cruise map and a high res boost map that you could switch at ~ 100kpa.
I'm surprised this post didn't get more responses. I just figured I'm retarded.
#4
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the MS3 has a feature like this called "idle advance" (and another one for idle VE).
it waits until closed loop idle parameters are met plus delays and then uses the idle advance (or VE) table.
so yeah, I'd say you could do it.
the parameters for idle advance are (my settings):
TPS Below value (1%)
RPM below value (1500)
load above value (15%/kpa)
CLT above value (50C)
after delay (1sec)
it waits until closed loop idle parameters are met plus delays and then uses the idle advance (or VE) table.
so yeah, I'd say you could do it.
the parameters for idle advance are (my settings):
TPS Below value (1%)
RPM below value (1500)
load above value (15%/kpa)
CLT above value (50C)
after delay (1sec)
#6
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The table switching is instant. It's recommended that you overlap your break point from table1 to table3, though I know some people do not.
However if you can demonstrate (with datalogs to back it up!) that your car needs more resolution than 16x16, we would like to see.
I think that you'll find that more "resolution" in cruise not only isn't necessary, but adds significant complexity to getting a smooth driving tune.
However if you can demonstrate (with datalogs to back it up!) that your car needs more resolution than 16x16, we would like to see.
I think that you'll find that more "resolution" in cruise not only isn't necessary, but adds significant complexity to getting a smooth driving tune.
#7
the MS3 has a feature like this called "idle advance" (and another one for idle VE).
it waits until closed loop idle parameters are met plus delays and then uses the idle advance (or VE) table.
so yeah, I'd say you could do it.
the parameters for idle advance are (my settings):
TPS Below value (1%)
RPM below value (1500)
load above value (15%/kpa)
CLT above value (50C)
after delay (1sec)
it waits until closed loop idle parameters are met plus delays and then uses the idle advance (or VE) table.
so yeah, I'd say you could do it.
the parameters for idle advance are (my settings):
TPS Below value (1%)
RPM below value (1500)
load above value (15%/kpa)
CLT above value (50C)
after delay (1sec)
The table switching is instant. It's recommended that you overlap your break point from table1 to table3, though I know some people do not.
However if you can demonstrate (with datalogs to back it up!) that your car needs more resolution than 16x16, we would like to see.
I think that you'll find that more "resolution" in cruise not only isn't necessary, but adds significant complexity to getting a smooth driving tune.
However if you can demonstrate (with datalogs to back it up!) that your car needs more resolution than 16x16, we would like to see.
I think that you'll find that more "resolution" in cruise not only isn't necessary, but adds significant complexity to getting a smooth driving tune.
That being said, I really want it for an idle table.
use dual maps for this. make a 16x30 table. or it that a ms3 thing again?
For spark you could do a 22x12 or a 12x22 depending on the same thing MAP vs RPM
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When you're working with a management system with very large tables, what most tuners will do is skip to every 3rd or 4th row, and interpolate between the tuned rows. Why? Because the added table size does nothing for performance. Also systems with very large tables generally do not allow for custom break points, where we can set them wherever we need/want them.
I've heard people complain that MS2/MS3 16x16 tables are too big. That's why in MS2 you can bump your VE table back down to 12x12 if you want.
Here's a fun video of the Huber Mustang. Nearly 1000 whp 40 psi turbo 4-banger. It runs a fancy MS1 based system. 12x12 tables. This is a 9 sec run, but he's well in the 8's now.
#9
Why? What do you gain? Your VE is going to be pretty linear, so adding "resolution" doesn't improve your tune any. It just makes for more cells to tune.
When you're working with a management system with very large tables, what most tuners will do is skip to every 3rd or 4th row, and interpolate between the tuned rows. Why? Because the added table size does nothing for performance.
When you're working with a management system with very large tables, what most tuners will do is skip to every 3rd or 4th row, and interpolate between the tuned rows. Why? Because the added table size does nothing for performance.
I'm merely pondering ways to get a little extra from the MS2.
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I just answered the why not, or at least hit the highlights. But if you can demonstrate a need, with datalogs to back it up, then I will present a case to Ken.
Yes. You can set all breakpoints and the MegaSquirt uses a weighted interpolation between cells.
Yes. You can set all breakpoints and the MegaSquirt uses a weighted interpolation between cells.
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yeah all MS3 maps have fully parametric breakpoints.
#19
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.
#20
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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?