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Subaru SI drive & DBW Tuning

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Hey Guys,

So I recently set my car back to stock (except for a 3 port) to start tuning it myself and one of the first things I noticed is that the throttle pedal seems to kind of .. "suck" with the stock tune. It feels pretty unresponsive throughout most of the pedal travel regardless of which I, S, or #S mode its in. This was kind of annoying, so I set off to see what I could do about this...

From what I can tell I have 3 main tables at my disposal here:

Requested Torque By Throttle %-age - Maps a throttle angle to a req torque value by rpm

Requested Torque Base By RPM - Used to convert Req torq into a ratio by dividing by the values in this table

And lastly...

Target throttle plate position based on req torque ratio

Initially I made some pretty significant adjustments to the Target throttle plate table as it looked the most un-natural to me where it seems to be targeting a very low amount of throttle opening for most of the pedal travel until you hit 100%. I adjusted it as follows...

This looked more linear to me so I was hoping it would yield a more natural pedal feel. Boy was I wrong :D. Luckily it was still drivable but It wasn't very fun and it was super sensitive going from on to off throttle. It was however a lot easier to get going from a stop and I definitely wouldn't classify it as "unresponsive".

Anyhow, the TLDR here is what (if any) method can I use to tune these tables to get a throttle pedal that feels a bit more natural without continuing to just guess and check? Should this just be done through the Si drive/Req torq tables instead of target throttle? Anyone care to share some examples of these tables tuned in a way they prefer? Anything I'm completely missing related to tuning how the pedal feels or responds?

My assumptions around what would make the throttle pedal feel "good" or "more responsive" would be to establish a relationship between the throttle pedal and the airflow into the engine that is at least somewhat more linear than it is now.

Trying to achieve this through the above tables seems pretty non-intuitive as they seem to take what could be a direct relationship (throttle pedal% -> airflow), and kind of muddy it by converting it to a requested torque ratio that varies by RPM for whatever reason.

The main concept to remember is the throttle position sufficient to provide no significant pressure drop across the throttle plate at a given engine condition is already providing max effort so to speak. For example before the turbo spools significantly at 2000 RPM, 30% plate position may provide the same engine behavior as 100%.

Also airflow increases dramatically as the throttle opens a little bit and then airflow increase with more throttle angle diminishes severely as you open the plate further. It is not a linear behavior.

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