Logging the mapped point weight % I noticed that before my car is started it is 100% on table 14. as my car starts it goes to table 0. I looked at the spark timing for the related load and rpms and noticed there is a spike in table 14 around the.95 load 450rpm range and another spike in table 0 at the .25 load 750 rpm range. I'm guessing this is there just for starting the car and if so the other mapped points with valleys and peaks have a purpose for handling different conditions. knowing this, keeping the differences between mapped points could be quite important for optimal spark. I have the Coyote cook book by LaSota and it is a great resource. They give very specific advice about what these engines need and for any one looking for a place to start that book is a great place. In this book they give examples of mapped point spark tables and explain how they got to them. Its an OK method and as they even mentioned in the book mathematicians may have a problem with the way they choose to do it. One of the big problems I had with their method was it did not handle the negative values. The other problem I had was looking through their examples the different colors gave an illusion of the charts being very different but when I looked at the numbers all the tables had come out very similar. looking at the tables in my 2015 file the charts were all quite different with peaks and valleys varying between charts. The example they used was from a 11-14 ecu and the original values may not have been very different to begin with. To solve my problem I worked with my coworker to come up with a spreadsheet to deal with the differences in the many different tables quickly. I have played around experimenting with it and found it works very well. I've attached it so feel free to try it out. As always pay attention to changes it makes and be careful, I recommend only make small changes in select areas. Use at your own risk. Feed back on it is always welcome.
Cool thanks for doing this, I'm also knee deep into learning how ignition timing is calculated. Here is some feedback for your tables:
1. Could you label each table so the user knows which mapped point table they are dealing with
2. Maybe add an instruction tab to explain how to use the spreadsheet
3. What is the logic for the modified tables, maybe its just table 0 modified to user preference?
4. Personally I'd rather make Mapped Point 22 my reference table since thats the one my car uses at WOT and high rpm
Ignore any numbers in the spreadsheet, they are not accurate and were just number I was playing with to gauge changes that would happen. The top left table would be the stock table you choose as the starting table to modify. My advice would be to scan your cars mapped points weight % and find which table it uses for WOT. This seems like it could be any table between 14-25 on the 15's. Personally I choose mapped point 25 to start with as it looked to be the smoothest also it was where my car always tried to go at WOT between 5k-7k rpms when conditions were ideal. The top right table would be the modifications you have made to your starting table. the bottom left would be the stock table of all other mapped points. The bottom right would be the new values you would replace them with. I had a sperad sheet with 26 different tables but found i only copied one table at a time so only two were necessary. Im also going to point out the load axis for MBT spark and borderline spark have different values this doesn't affect the spreadsheet but while modifying tables you need to either account for this or adjust the numbers to simplify. I can add Borders, lables and colors for aesthetics later. Thank you for the feedback.
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