Mazda 6 Forums banner
1 - 3 of 3 Posts

·
Registered
Joined
·
4,202 Posts
Discussion Starter · #1 ·
@RandR10 said
Seriously though; TalonTsi90, I'm genuinely curious about the technical aspects of this. What is it about a stepper motor that makes it impossible for a short coming from the throttle signal to cause it to lock open? Honestly, I was worried about the same thing when I started thinking about it and an internet search has devolved into a series of how-it-works primers that give no useful information about how a stepper motor works. I'm quite green when it comes to electronics and I'd like to learn more. Stepper motors are of particular interest because I'd like to get into CNC at some point.
So, the reason throttle controllers are even a thing is, since some time in the 2000's they went to electronic throttles (ET's) instead of a physical cable that connects the pedal and throttle plate. I didnt know this till i got my 3 and started reading to learn and realized about throttle lag. My 2006 6 didnt have this 'effect' or it was so minimal that i never noticed it.

Im guessing due to emissions laws, the ECU made the ET seem or feel dumber and number over time. So, when you stomp on the gas pedal, the ECU analyzes a lot of info like RPM, load, gear and im sure a lot of other sensor data, and then tells the ET how far to open the butterfly. The issue is, its not always (or possible ever, i dont know) a 1:1 ratio. If you give 100% throttle in 6th gear at 2000rpm, you dont get 100% opening of the butterfly. Try this is 2nd at 4000rpm and youll most likely get full throttle opening.

What a throttle controller does is, allow us to enhance this operation without the expense of a tune. For me, it was about 1/10th the cost vs a tune. It tells the ECU that either you arent pushing the pedal as hard, or the opposite and increases the ratio of gas pedal, so a cut or boost.

From what i understand and have experienced, the ECU still maintains 100% control over the ET, the controller just fools it into thinking the gas pedal is acting differently. So, in a bad situation, the ECU can still cut (to keep from over accel) or boost (to keep from stalling the motor) the ET regardless of the input from the pedal circuit.

To answer the CNC bit, this guy has good explanations and i love his channel.

Ok, discuss, but nicely, i will as well :)
 

·
Registered
Joined
·
38 Posts
Love This Old Tony. Dude cracks me up. I actually had done some research and was going to post my findings, but alas the discussion got shut down before I could. Anyway, I think I answered my own question by watching the following video.


The stepper motor works by energizing specific coils within the motor stator that lock the motor rotor into a specific position. When you move the throttle, the ECU reads that data and sends a corresponding signal to the stepper motor in the throttle body about what position it wants, which actually ends up being converted into a series of of steps (thus the stepper motor moniker), that will move the throttle from one position to the next and then the next, over and over again until you get to the position that's being called for by the ECU. I think if something shorted, it would not send the proper signal and that's it, allowing the return spring to slap the throttle shut. Worst case it burns up the ECU electronics and the engine shuts off. The throttle pedal doesn't have a direct interface with the throttle body as far as I can tell (much to my chagrin). Either way, not exactly ideal, but also not a runaway acceleration event which was originally feared.

Something else you mentioned above I'm still a little confused on. You said it changes the ratio of the pedal, kind of like those throttle body cam mods back in the day which would get you to WOT with less pedal travel. I hope that's not what it does because this will just annoy me. What I want is a more linear relationship between my foot pedal and the actual throttle plate. When I call for a given throttle position with my foot, I want it to do so instantly (or at least quick enough that I can't perceive the delay). In other words, I want complete control of what the engine is doing. If all it does is open the throttle more requiring less pedal travel, it's going to be harder to control, which is the opposite of what I'm going for.
 

·
Registered
Joined
·
4,202 Posts
Discussion Starter · #3 ·
Something else you mentioned above I'm still a little confused on. You said it changes the ratio of the pedal, kind of like those throttle body cam mods back in the day which would get you to WOT with less pedal travel. I hope that's not what it does because this will just annoy me. What I want is a more linear relationship between my foot pedal and the actual throttle plate. When I call for a given throttle position with my foot, I want it to do so instantly (or at least quick enough that I can't perceive the delay). In other words, I want complete control of what the engine is doing. If all it does is open the throttle more requiring less pedal travel, it's going to be harder to control, which is the opposite of what I'm going for.
Well, there are 9 settings of "effectiveness" and other than being really sensitive on higher settings (i have a manual so it can make low speeds look like you cant drive a clutch). I use #2 and its a decent balance for everyday driving. If i were needing to downshift a lot and rev match, #3 is better. Im not 100% sure its 1:1 linear, but it completely transforms the car and how it feels.
 
1 - 3 of 3 Posts
Top