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Electronic Throttle Control

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Hey Andre,

Do you have any input on how Torque Based-ETC Systems are tuned. What is the relationship between Requested Torque, Accelerator Position and RPM and what does this mean to you as a tuner? I understand that Requested Torque is used as an input in the Target Throttle Angles Table and is used to determine Target Throttle Position, i.e. engine acceleration response. Does this type of system allow the user to define the "nature" or "personality" of the Engine Response as a whole? If so, what parameters are most important to you as a tuner to modify or adjust to achieve a desirable result? Thanks for any input!

For the most part a torque based throttle request is a technique a manufacturer uses to control the throttle opening in response to the driver's torque demand rather than directly via driver throttle position. You can affect the feel and throttle response of the engine by altering the requested torque table and raising the requested torque vs driver throttle position value will result in more throttle opening and a crisper, more aggressive throttle response. Particularly if you are modifying the engine and achieving more power/torque, it's usually essential to raise the requested torque values to match the engine's actual power torque delivery otherwise you may not reach full throttle in certain areas of operation.

When you're making changes to these tables I suggest making changes of 10% at a time before testing. This should be large enough for you to feel the effect without being too large. It's also worthwhile to log the actual throttle opening to confirm what is really happening.

Since you have to adjust the values to match the engines actual output capabilities, it's safe to assume that this is a table left for the end of the tune? Would you just use your dyno output values to fill in this table directly? Thanks for the info!

The answer is that it depends (not useful I know, but read on).

In most cases the requested torque table can simply be used to adjust the 'feel' of the throttle. in this case you can leave this until the end of the tune. If the ECU is smart enough though and you're increasing the power significantly, not raising the requested torque values at WOT will result in the ECU closing the throttle slightly and obviously messing with the tune. That's why it's important to watch what is happening on a logger.