Finally, a decent tune .... next step, spark
10-08-2009, 03:45 AM
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Finally, a decent tune .... next step, spark
Here is my latest and greatest .msq file: http://www.snarc.net/evan_hr_69.msq .... 69 is always a fun number. 
Some things I realized while tuning tonight, that I didn't realize in the past 14 months of having a 'squirted Miata:
1., I had mostly ignored the bottom row (20 kPa) of my VE table, instead letting MLV's VE Analyzer make suggestions with a minimum MAP of 30 .... I've been doing that because Paul taught me all along that MLV/VEA doesn't do well at idle, which should be tuned manually .... he's correct .... but what I didn't realize is that the non-idle cells in that row (everything above 1,000) were super-rich and were ******* with the cells above them, since MegaTune interpolates. So tonight I leaned them out, and now my car runs much better when it's just puttering along at relatively low RPM (2000-3500) in third and fourth gear. Now it feels like an ordinary car in that scenario, not a diesel truck!
2. I had a giant lean spot in the lower-right corner of the table, not counting the bottom row and right-most column. That explains the jolt I felt when I stepped on the gas from low/medium RPM in passing gear on the highway. I added some fuel there, now life is smoooooooth.
3. I now realize why my car had so many misfires .... not because there wasn't enough spark, but because there was too much fuel.
4. I learned those three things not by datalogging and then trying to comprehend the line graphs, but by opening MegaTune's VE table, and keeping one eye on that with another eye on my wideband .... who needs to watch the road, anyway?
That's how I started to realize what my car was doing and why it was doing it.
So .... I don't know if this post helps anyone else, but maybe some other people can learn from my mistakes.
Meanwhile, now that I finally have a logical fuel table, I suppose it's time that I learn more about tuning the spark table.
First major question: is it vital that the RPM columns in the spark table are the same as those in the VE table? I assume yes, so we can compare apples-to-apples.
Second major question: is there some tool for tuning spark, equivalent in usage to MLV / VE Analyzer?
Some things I realized while tuning tonight, that I didn't realize in the past 14 months of having a 'squirted Miata:
1., I had mostly ignored the bottom row (20 kPa) of my VE table, instead letting MLV's VE Analyzer make suggestions with a minimum MAP of 30 .... I've been doing that because Paul taught me all along that MLV/VEA doesn't do well at idle, which should be tuned manually .... he's correct .... but what I didn't realize is that the non-idle cells in that row (everything above 1,000) were super-rich and were ******* with the cells above them, since MegaTune interpolates. So tonight I leaned them out, and now my car runs much better when it's just puttering along at relatively low RPM (2000-3500) in third and fourth gear. Now it feels like an ordinary car in that scenario, not a diesel truck!
2. I had a giant lean spot in the lower-right corner of the table, not counting the bottom row and right-most column. That explains the jolt I felt when I stepped on the gas from low/medium RPM in passing gear on the highway. I added some fuel there, now life is smoooooooth.
3. I now realize why my car had so many misfires .... not because there wasn't enough spark, but because there was too much fuel.
4. I learned those three things not by datalogging and then trying to comprehend the line graphs, but by opening MegaTune's VE table, and keeping one eye on that with another eye on my wideband .... who needs to watch the road, anyway?
That's how I started to realize what my car was doing and why it was doing it.So .... I don't know if this post helps anyone else, but maybe some other people can learn from my mistakes.
Meanwhile, now that I finally have a logical fuel table, I suppose it's time that I learn more about tuning the spark table.
First major question: is it vital that the RPM columns in the spark table are the same as those in the VE table? I assume yes, so we can compare apples-to-apples.
Second major question: is there some tool for tuning spark, equivalent in usage to MLV / VE Analyzer?
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10-08-2009, 03:07 PM
#6
I learned those three things not by datalogging and then trying to comprehend the line graphs, but by opening MegaTune's VE table, and keeping one eye on that with another eye on my wideband .... who needs to watch the road, anyway? That's how I started to realize what my car was doing and why it was doing it.
That's how I started to realize what my car was doing and why it was doing it.You're right, I learn a ton by watching that. I generally autotune the whole map, then block select and "undo" the bottom row, or see what the changes are and decide what I want to do about them.
It's not the BEST tune, but the car was way faster than it was on my super conservative map. But, after roughing out fuel, dyno time really is worth it.
That's not really contributing, is it? If you want to start a politics thread go ahead, let's talk about cars here.
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10-08-2009, 09:58 PM
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1., I had mostly ignored the bottom row (20 kPa) of my VE table, instead letting MLV's VE Analyzer make suggestions with a minimum MAP of 30 .... I've been doing that because Paul taught me all along that MLV/VEA doesn't do well at idle, which should be tuned manually .... he's correct .... but what I didn't realize is that the non-idle cells in that row (everything above 1,000) were super-rich and were ******* with the cells above them, since MegaTune interpolates. So tonight I leaned them out, and now my car runs much better when it's just puttering along at relatively low RPM (2000-3500) in third and fourth gear. Now it feels like an ordinary car in that scenario, not a diesel truck!
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