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Looking for inputs. Please see 9:18 of the Top gear video where the throttle position is fed from a computer program to make the engine revs play a tune. I know our cars have fly by wire throttle control. I've thought about using a linear servo to simulate the throttle press but that might be too slow.

What is the best way to accomplish this by hacking into the throttle potentiometer control? I am going to be using an Arduino or something similar to do the programming. With a heavy flywheel, it the engine going to be able to respond quick enough?

 

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i was thinking that the F1 demonstration works because of the crazy large rev range and fast throttle response. the large range is needed in order to access all of the song's notes.

in order to do this, one could overwrite target engine idle speed RAM values in the ecu via a custom program or an obd cable. i don't think that this route is trivial on the evora, though.

an alternative would be to use a digital to analog converter microchip with the arduino in place of the pedal position sensor. i expect the sensor to be a simple 0-5V output, so a DtoA chip could work directly off of the Arduino power supply.

if you're really lucky, throttle position might be sent from the pedal to the ecu over CAN or LIN (instead of as an analog sensor input)- overwriting command this would be as simple as injecting rogue packets. i guess i don't really know how the evora pedal sensor works in this regard.
 

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Yeah, the engine won't have nearly the response you need.

If you listen in the engine bay with the engine off though, you can hear a hum coming from the throttle body. This frequency can be altered to play a song, and in most cases won't change the operation (so it can be done when the engine is idling).

I've done it :) Well, I didn't program the full song, but I could play different notes. And this was with an aftermarket standalone that gave me the full access to the PWM frequency. I have heard brushless motors program startup songs though in their firmware using the same concept.
 
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