So I checked and the FRPP3 tune has everyone of these changes already made except for the Cyl Mult tables; however these are a multiplier to the Cylinder to Cylinder offset, which mine is actually all zeros.
I will try to add some more timing to my Borderline spark tables and see how it responds.
What's your spark source below 6400 RPM?
Borderline
My car seems to respond to Borderline changes, but it still reads Base as Spark Source at WOT past a certain point (around 3800 rpm seems to be it, 3.7 V6 Mustang). MBT is set exactly 4 degrees higher than Borderline. Knock Retard goes to zero (exactly zero) when it transitions to Base, don't know how that relates, but it's a pattern I noticed. Also, my Lambda, IAT and Coolant Modifiers are zeroed for normal operating conditions, i.e. no correction for WOT Lambda, no correction for average ECT, and no correction for normal IAT's.
Any updates on this?
Are we just missing the "base" table?
In another thread I saw this posted, but don't have the table in my tune. Anyone know what the table ID is?
base-spark.png
On the s550, that's 44586 (BASE MBT), 44585 (BASE)
If that helps you at all.
I'm actually having a similar issue with this base spark source popping up
Thanks, I'll see if they can add it!
Base is your MBT tables. It's not an issue that it's popping up. You spark runs off both borderline and MBT/ base tables, most of the time it is at low loads when MBT is less than borderline tables but the spark is using MBT as the lesser of the two.
Originally Posted by Thatwhite5.0
Okay cool, I had wondered if that was the case in the past. Thanks!
Any ideas about Cold Start Emissions Reduction? That keeps popping up randomly and causing big down spikes in advance.
Your Spark Source goes to Base if your commanded BKT is higher than MBT, that's based on my experience when tuning the new EcoBoost engines.
There are also numerous adders/modifiers for BKT and MBT. One of which is lambda for BKT, and lambda for MBT. If you look at it, it generally reduces your MBT by 2-3 degrees at 0.85-0.90 lambda (basically when you are running PE lambda at WOT). So if you tried to add too much BKT, it will switch to the lower of the 2, which would be MBT.
This was my first thought on the base spark source, however, my MBT values are higher in this case than my borderline where it is switching to base spark source.
That made sense to me as well because when hitting "Base" knock advance would drop off so I figured it was hitting MBT value.
I'm going to play with it some more this afternoon.
I'll see if I can post a log later when back at my laptop.
I zero'd out the additional adders to narrow it down, may have overlooked a cell in the MBT tables.
Last edited by BravoAlphaPerf; 05-18-2018 at 11:54 AM.
MBT/base spark runs in between borderline and MBT spark tables. MBT is like a limit to knock sensor advance when conditions are right. When you're at WOT, if you have borderline set to 22 degrees with your MBT for the same set of cells are set to 28 degrees. Knock advance is set to 3, add in all your multipliers and you'll be running some where around 26 27 degrees or possibly less due to your multipliers pulling spark. Even though timing is running closer to MBT's value, your spark source will say borderline
borderline + knock advance + multipliers = x timing
spark_1.JPG
At low loads, 10% to 40% load, you may see Base spark source. Cruising at low loads, MBT is not a limit. Borderlines number will go above MBT and advance further than MBT with timing will stay very close to your MBT value.. The cross between MBT and borderline usually happens around 35% load.
spark_2.JPG
Spark advance will follow the lowest of the two values. MBT is supposed to be near the best timing before spark knock. But with mods done to the car, that's bound to change.
CS86. Check your distance tables for VCT Emissions reduction and 0 out the tables for it. Look at your datalog and see which mapped point you're in when you're getting the problem and make sure the spark tables are flowing right. Make sure spark isn't going back and forth between Borderline and MBT.
Last edited by Thatwhite5.0; 05-18-2018 at 01:34 PM.
Yup, VCT Emissions Reduction mapped points and distance tables are both zeroed out. Now that I write this, maybe I should set all the Emissions Reduction mapped points to an MP I have disabled instead MP0, since MP0 and MP1 is when this behavior shows up.
Here's a log of it...
Have you tried increasing the cold start spark limit tables?
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