Ideal AFR targets for fuel tables
 

Hey, so we all know the standard 13.1 AFR is ideal for power and all that fun stuff, but we don't have a definitive thread showing what a baseline table SHOULD look like before you get into engine specific AFR tuning..

The idea here is to have a visual representation that covers entire tables instead of quotes about specific parts of the tables, like referencing WOT specific cells. I'm attaching an excel sheet with the stock tables and I'm asking someone experienced to just modify it to show what your resultant AFR would be at it's best.

DISCLAIMER: I know there are some people who just copy and paste stuff because they can't be bothered to learn how to tune themselves. SO DON'T USE ANY OF THESE TABLES IN YOUR TUNES! Just because thats the target, doesn't mean thats what the engine will do.. This is educational, people can ask questions about why certain parts of the table are the way they are and get feedback.

THANKS! Looking forward to the hilarity that is sure to ensue from this..

I guess I should mention this is for NA but I won't limit it to that if people ask questions :/ Pretty sure theres a ton of threads about FI tuning that have this kind of visual aid already though.

What other mods do you have? If none you really shouldn't change your tables. You can gain a little power leaning it out on the top end and giving it some timing, but that will cook your cat.

My signature lists my mods (that car was totalled by some douche while I was stopped at a red light), but I have a second RX-8 with similar mods now actually.

I guess a basic tune for a stock car would be a good place to start though, I really only touch the cells that my datalogs tell me I'm hitting but thats a small percentage of the tables.. So perhaps a leaned out table to start?

I'm mainly curious what people consider safe goals for leaning out the tables, it would be nice to get input on this because theres areas on there that dip as low as 9.2 AFR.. I know you would never hit those cells with an NA motor but some of the cells around 100% load are still into the nines that I have hit. I'm a little hesitant to lean those out past 12.3 but only because I'm not sure where it gets sketchy to lean the table past that. Right now I have most of my high load high rpm areas sitting around 12 which is still a little rich for my blood.

I guess it's also worth pointing out I've adjusted the ignition split to my liking but I haven't really touched on the ignition advance aspect yet, I need to pick up a something to listen for knock and detonation before I play with that :P

before touching anything you should make sure that your MAF and injectors are appropriately scaled or you may be in for a world of hurt.

the target numbers in the map are not relevant, only what an accurate AFR sensor measures is all that matters

hubris + ignition tuning does not a good combination make ...

I made the MAF scaling excel sheet in one of the fairly viewed threads so I know that much.

I also know what you put into the tables doesn't equal what you get, if I'm aiming for 13.5 but my logs say it's leaner then that I may need to make the table more rich for the resultant AFR to match 13.5.. Perhaps I worded that incorrectly when I tried explaining initially...

I guess what I'm trying to see is a table of what you WANT your logs to show... Not what it refers to when it decides how to operate for that cycle.

Here's what I've been working on just to show I'm not completely inept! :P The only reason I haven't expanded this into AFR tuning yet is because I want to switch a few more closed loop exit parameters to dynamic references that way the workbook will write itself for each user.. I know that different years of RX-8s have different gears assigned to different fuel tables but I'll figure that out once I get this one refined enough.

I should warn you I build custom PCs and mine takes about 1-2 minutes to open that workbook due to calculations, I have a watercooled $4000 PC. On a more reasonable Surface pro 2 it takes a good 10 minutes.. So be yes it will open, just takes a bit :P The one I post here normally only has one data line where you put your log info, this is a sample with 45000 lines of my logging.

The fuel table pages show the average that your car is reading to the right of the stock tables..

If you have suggestions lemme know! I know I could do more with another datalogger but I bought the AP and found with enough datamining skills I don't need all of the extra stuff offered by better solutions. (*shrugs*) I'm stubborn..

Biggest issues I've got with the Cobb AP is that it doesn't offer a target AFR in it's logs.. I would love to have that, I know that many sensors adjust the fuel table AFRs to get the target AFR the engine decides on but I can't account for that unless I know exactly how and when the ecu accesses each modifier table to come up with its target.. Also have the issue of latency increasing with the higher RPMs, if I knew how many milliseconds it was off by on the AFR reading at various RPMs I could account for that in the table references. It may not be a huge issue but it makes the difference between fine tuning and tuning without regard for that latency which creates an inherent latency error the higher the rpms are.. If you guys have a some knowledge on the input latency issue PLEASE tell me, it's not hard to create an exponential trend formula that can account for it based on RPM but I have no idea when the latency becomes an issue and how quickly it increases.. :/ I can be a number crunching beast but I need info, and I get it from you guys since I have limited funds. :P