Gents, I have a couple questions for the guru's.
What scenario(s) causes the PCM to jump between High or Low Octane Spark Maps?
Has anyone found that the High TPS Min Spark Advance map in the Spark Retard section possibly has too much advance set for high TPS scenarios? I had to pull a good amount of timing at WOT and now my PE table seems to conflict with this smaller map.
I don't know if the Min advance is absolute min during spark retard events, or the min advance coming out of the spark retard event....
Open to thoughts on these...
I think I have maybe figured this one out by reading the help files in hptuners.
I'm still interested in anyones comments though on my second question about High TPS min spark advance. If I don't get a response I'll just have to go try it out.
It was my understanding the the ECU always tries to use the HIGH Octane tables, and when it see's knock blends the LOW Octane tables in to try and get rid of knock.
FU Tuning
the high tps minimum spark tables I always thought were the MINIMUM amount of timing the PCM is allowed to run...
in other words, if knock retard and multipliers tried to pull the timing down to 6*, if the minimum timing is 12* it wouldn't go below the minimum timing.
I never touched the high tps min spark settings...
I usually take the PE HO spark table and copy it over the PE LO spark table and run 93 octane.
leave the non PE tables alone, that way when you're just cruising the PCM has a bit of breathing room so far as the spark goes... but when you mat it, the PCM will stick to a nice stable spark table that will better utilize the higher octane fuel you're using.
if you want to try advancing the spark, you can do that too.. but I always make sure both PE tables (LO and HO) are identical, that way the timing is always predictable.
Guys - thanks to both of you for your comments - this really helps me straighten out my approach and understanding.
I haven't addressed my low octane tables like I should and they're starting to conflict with my high octane tables so that would hose up the interpolation.
I need to pull some timing from the high TPS min spark settings and deal with my low octane tables because I want to run closer to 5 degrees or less total timing in some scenarios and that conflicts with my PE and non-PE high octane tables.
Also - great bit about the low octane tables - although I think I may just reduce the timing in the low octane tables by the same % of total timing pulled from the high octane table.
Man this stuff is fun sometimes. I just wish my MAP sensor on back-order would just arrive so i can fake a 3bar tune some time this summer/fall.
heavyclutch wrote:G
Also - great bit about the low octane tables - although I think I may just reduce the timing in the low octane tables by the same % of total timing pulled from the high octane table.
Thats what I was planing on doing, setting both table equal while I tuned, but just subtracting a set value from the whole low octane table once I was done, maybe like 4*'s just in case I get bad gas I wont have constant KR.
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On this subject, I wonder if it is really interpolating between the tables after learning the KR. I have some experience where the advance in cells that experienced KR seems to swing between the two values rather than just keeping a steady advance somewhere in between.
It's also curious that after a write calibration, it's still doing this, even after pulling some advance from the HO table where affected the KR. Shouldn't the PCM be advancing towards the HO table if knock is no longer detected, or does it require a write entire to clear the learn? Or maybe the best remedy is to do as PJ said and flash the HO and LO PE tablesidentically after they are tuned for no KR, drive it, then flash a new tune with some advance subracted from the LO table.
