Since this is a broad-open ended question, here's what I can say. This is based on what's been publicly posted about how Subarus drive by wire and engine control systems work.
It could be called a pedal-follower system. @
mad_sb 's thread explained it pretty thoroughly, including this post:
Quote:
Originally Posted by Shankenstein
So to put this in geek-speak:
T_EST = f(N, LOAD) using either map "A" or "B"
T_WOT = f(N)
T_REQ = f(APP, N) using either map "Normal" or "Sport"
T_RATIO = T_REQ / T_WOT
TA_REQ = f(T_RATIO, N)
TA_CUR = current throttle angle
TA_DELTA = TA_REQ - TA_CUR
TA_TARGET= filter(TA_CUR, TA_DELTA, K) where K is the adaptive filter gain
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Basically a map(s) requests torque based on pedal position, another map looks up estimated torque based on speed and load, another map looks up throttle position needed to get current torque to that requested value.
Quote:
Originally Posted by Kodename47
I've noticed that the requested values dip at around 4k.
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So here's what most likely happened. Somebody at Subaru or Toyota ran an engine dyno at a bunch of steady-state speed & load points. So at 4000rpm 1.00 g/rev they ran the engine for maybe a minute. All the spark timing, AVCS, etc were all adjusted at each point. The dyno measured the engine torque. It was all spit out into a big Excel-readable file by the dyno control system.
Then they loaded the data from the file either directly into the maps for the ECU, or into some Matlab tool or Excel macro which processed it and spit out the values. There wasn't necessarily a ton of thought put into the numbers in the table. Some guy followed some procedure, that's all. The torque curve of the engine was most likely established on the dyno at each individual point before those maps were ever made.
The FA20 doesn't use an actual model of engine torque, not from what's been seen so far. It's just those look-up tables, which as I said came right from an engine dyno into the maps with maybe some tweaks on top of that.