The wiki assumes everyone starts with a standard(stock) car. In reality people add hardware from the start, especially with conversions and it throws most of the theory off track.
Understood. The reason the wiki is written from that perspective, is that it is assumes that if you have a 2.7t, you're probably looking for either a stage 1 tune (stock everything, just ECU flash) or a stage 3 tune (turbos, injector, MAF)
You point is a valid one, though, there needs to be much more explanation about which map modifications are for which goal. I'll try to go through the wiki at some point to try to fix that. If you have SPECIFIC suggestions about wording, they are more than welcome, especially if you just want to log in and change the wording yourself!
It seems now that now I have rl_w and ps_w closer to to where it should be, is it right that I can tweak any areas in the high load areas with KFKHFM to get closer to actual boost? Then I can sort fuel in those areas with KFLF or FKKVS? Or is that not necessary?
So basically, fixing fueling is in two steps (most people are lazy and do it in one, either all in KFKFHM, KFLF, or FKKVS), the end goal being to get fuel trims near zero (or, for a narrow band car, add one wideband sensor readings to match req lambda).
1) MAF calibration (MLHFM, KFKHFM)
2) Fueling system calibration (KFLF, FKKVS)
As I said, most people are lazy and do it all in one step in one (or more) of those three maps (not MLHFM), depending on which axis values you like working with the most. You can too, if you like.
Now, if you are wanting to be exact, you can to do them one at a time, independently
for 1), typically, you'll have a MLHFM from the MAF manufacturer to start with. KFKHFM should be calibrated by comparing ps_w with actual boost (during WOT), and req load with actual load (in areas where you expect actual load to match req - e.g. req boost and actual boost are the same). You really can be arbitrarily far off with either (within reason) at the end of the day, though, as long as the discrepancy looks consistent (no really big swings either way).
Then you can move on to 2).
Now, FKKVS is SUPPOSED to be only for tuning returnless fuel system nonlinearities, but KFLF might not provide the granularity you need at high load (you tpically end up only getting 4 or 5 cells to work with for WOT fueling), so a lot of people do more tweaking in both FKKVS and KFKHFM to get fuel trims sane.
If you choose the KFKHFM route, you may notice that ps_w and actual load might start to wander from actual boost and req boost (respectively), but IMO that isn't a big deal, you really want your fueling to be right over having an accurate ps_w or load.
Long story short: don't worry about small ps_w or rl_w discrepancies, fueling is more important.
Hope that helps.
BTW none of that is in the wiki because of the "more than one way to skin a cat" thing... YMMV, I'm sure many will disagree with what ive posted.
