Discussing Throttle-by-wire, throttle response, and Pedal Commander 'improvements'

[Isopedella]

I put a PedalBox on my F3.

Its amazing how it woke it up.

Quote Originally Posted by BajaRon View Post
If this is true. Why such a huge difference regardless of how you treat the throttle before and after? I put a Pedalbox on my F3 and it has been amazing.

Snake oil maybeView attachment 206170:banghead:

Snake Oil. Big call - please expand on that.
I'm interested in your reply.

 

[DickB]

If this is true. Why such a huge difference regardless of how you treat the throttle before and after? I put a Pedalbox on my F3 and it has been amazing.

A small twist with Pedal Commander is translated into a large twist. That's all it does, and all it can do. This is interpreted by many as an increase in throttle response. If it makes you happy, cheers.

 

[DickB]

As Ron said, the Ryker and Spyder have different curves and the Ryker dose not a box.
All your tests have been on your Ryker.
a lot of the replies have been from Spyder owners.
Would it be possible for you to run the same tests on a Spyder.
Maybe it will show a different result which would benefit them.

Yes, of course it would be possible, but I don't have a Spyder. I did have a Mercedes SLK, and did extensive testing on it decades ago with a Sprint Booster. Same result. I don't have to test every throttle-by-wire vehicle on earth to know what the result will be. You say the Ryker and Spyder have "different curves" without any evidence (what is a "different curve" anyway?) When I fully twist the Ryker, the butterfly opens fully, rapidly. When I pushed the SLK pedal to the floor, the butterfly opened fully and rapidly. With and without the Sprint Booster. Why would a Spyder be any different?

If Pedal Commander makes such a difference, I challenge anyone to explain how it does so. I have explained exactly what it does and does not do. Explain to me please anything that I have stated that is not factual.

 

[DickB]

If the snake oil lives up to its claims and has 100% customer satisfaction, is it still snake oil?

Pedal Commander makes several claims that are not factual.

"The Pedal Commander throttle response controller gives drivers full control of their gas pedal sensitivity."

In Normal mode and Eco mode, butterfly opening is limited by the ECM, so Pedal Commander cannot override this, and give "full control".

"For example, you can press the gas pedal all the way, but the ECM will open only 80%."

True, but only in Eco mode.

"Second, the program decides how fast the throttle body will open. In other words, it doesn’t really matter how fast you are flooring the gas pedal. The ECM controls the speed of the signal so your foot can not make the throttle body faster."

As my data shows, the Ryker ECM does not do this, but rather opens the butterfly as fast as is physically possible.

"By sending the information to the computer this way, a couple of checks that the engine computer will make can be bypassed before sending the signal to open the throttle plate."

This is plainly false, as the ECM is not altered in any way. I asked a Pedal Commander representative several times about how Pedal Commander does this, and got no answer.

"It gives you the response of an "old school" throttle cable, with a 1:1 pedal-to-throttle acceleration ratio."

In any throttle-by-wire system, there is going to be a very small delay as I have explained and shown. Pedal Commander cannot change that. Without Pedal Commander in Sport mode, you do have a 1:1 ratio between twist and butterfly opening. Pedal Commander actually changes the ratio between twist and butterfly opening, as their own charts illustrate. I haven't measured an "old school" throttle cable, but with that system you still must overcome inertia in the system, so I doubt that you could open the butterfly any faster.

 

[BamaJohn]

:bdh: Let's go riding.......

 

[EdMat]

If you want to add something that really makes a difference, get something that doesn't change the exponential of the throttle, spend a few bucks more and get the dang thing flashed.

 

[BLUEKNIGHT911]

Dick :agree: ...... but you are :bdh: .....JMHO ....Mike :thumbup:

 

[Valkrocket]

IMHO. It's more the time it takes a human to twist the throttle wide open vs an immediate electronic response to wide open throttle with a slight twist of the wrist. All I know is that my Spyder really came to life when I added the Peddle Commander, so much so, that I had to dial it back from the Sport+ mode 3 numbers down as it made the throttle a little too twitchy in city traffic. I will not be removing my Pedal Commander anytime soon. I feel I have awoken a sleeping giant. hyea:

 

[DickB]

IMHO. It's more the time it takes a human to twist the throttle wide open vs an immediate electronic response to wide open throttle with a slight twist of the wrist. All I know is that my Spyder really came to life when I added the Peddle Commander, so much so, that I had to dial it back from the Sport+ mode 3 numbers down as it made the throttle a little too twitchy in city traffic. I will not be removing my Pedal Commander anytime soon. I feel I have awoken a sleeping giant. hyea:

As I pointed out, the time it took this human to fully twist the grip on a Ryker is 76 ms, or .076 seconds. Pedal Commander can accelerate partial twist signal by 35 ms, or .035 seconds. A blink of an eye is .1 seconds. So the "improvement" is a third of a blink of an eye. Keep in mind, this is an acceleration in the signal to the ECM, not an acceleration in actual butterfly opening. As I stated and measured, butterfly opening speed is limited by the throttle body slew rate. If the twist grip were replaced with a toggle switch, providing instant 100% signal to the ECM, the butterfly would not open instantly, but only as fast as the throttle body slew rate.

Pedal Commander does not emulate a toggle switch to provide an "immediate electronic response to wide open throttle with a slight twist of the wrist", per their own chart. In both cases, with and without Pedal Commander, you must twist fully to get wide open butterfly. Pedal Commander does not improve wide open butterfly response at all.

Making the twist grip "twitchy" is exactly what Pedal Commander does. If that makes you feel as if you have woken a sleeping giant, peace.

 

[nightfalcon]

As I pointed out, the time it took this human to fully twist the grip on a Ryker is 76 ms, or .076 seconds. Pedal Commander can accelerate partial twist signal by 35 ms, or .035 seconds. A blink of an eye is .1 seconds. So the "improvement" is a third of a blink of an eye. Keep in mind, this is an acceleration in the signal to the ECM, not an acceleration in actual butterfly opening. As I stated and measured, butterfly opening speed is limited by the throttle body slew rate. If the twist grip were replaced with a toggle switch, providing instant 100% signal to the ECM, the butterfly would not open instantly, but only as fast as the throttle body slew rate.

Pedal Commander does not emulate a toggle switch to provide an "immediate electronic response to wide open throttle with a slight twist of the wrist", per their own chart. In both cases, with and without Pedal Commander, you must twist fully to get wide open butterfly. Pedal Commander does not improve wide open butterfly response at all.

Making the twist grip "twitchy" is exactly what Pedal Commander does. If that makes you feel as if you have woken a sleeping giant, peace.

so....Pedal Commander tells the butterfly to open a third of a blink of an eye earlier than would otherwise be the case. The butterfly has a fixed maximum speed at which it can open but PC allows the command to do its thing 0.035ms earlier?

That is, while the throttle is being opened (as fast as the operator is able) PC is accelerating the response time from throttle input to butterfly actuation by 0.035ms (throughout throttle opening)?

Thus, while the butterfly isn't moving faster it is activating quicker.... albeit marginally....providing earlier acceleration which appears to be interpreted by riders as faster acceleration. In actual fact it is earlier acceleration which you say is akin to a twitchy throttle.

Have I got this right?

My brain is hurting.......

 

[DickB]

so....Pedal Commander tells the butterfly to open a third of a blink of an eye earlier than would otherwise be the case.

No, it doesn't. My statement regarding .035 seconds was confusing, so just forget about it for now. Let's look instead at what is happening moment by moment.

Normally (that is, not ECO mode, not traction control, etc.), the ECM is going to try to put the butterfly where the twist grip is telling it to. In other words, it is going to try to match the yellow signal (butterfly) to the blue signal (twist grip). The speed at which things are happening is evident by the slope of the signals - the faster things are happening, the steeper the slope of the signals.

Let's look first at the case where the signals are dropping - that is, when I released the twist grip. The slope of the twist grip (light blue) is very steep - things are happening fast - because the spring in the twist grip snaps the grip back very quickly. But the slope of the butterfly (yellow) is not as steep - not moving as fast as the twist grip. Why? Because the throttle body cannot physically move as fast as the twist grip is snapping back. It is moving as fast as it can. That speed - the slope of the falling yellow line - is the slew rate.

Now look at the case where the signals are rising - twisting open. Note that the slope of the yellow line is the same as when falling - in other words, moving at the maximum slew rate of the throttle body. Since the slope of the light blue line is the same, that tells us that I just happened to be twisting at the same rate as the maximum speed of the throttle body. If I would have tried and been able to twist even faster, the butterfly would not have opened any faster. The dark blue line represents what Pedal Commander would signal the ECM if I had one installed. So yes, while the slope is steeper, telling the ECM that I was twisting faster than I actually was, it would make no difference. Once the twist signal rate of change (slope) exceeds the throttle body slew rate, the butterfly can't move any faster.

 

[nightfalcon]

My comment....

"so....Pedal Commander tells the butterfly to open a third of a blink of an eye earlier than would otherwise be the case."

would've been better written... Pedal commander tells the butterfly to open wider than would otherwise be the case?

Given your comment....

"Because Pedal Commander does make the twist grip more sensitive, a small twist of the grip with it will open the butterfly more and thus deliver more power than the same small twist without it. This increase in sensitivity is perceived as improved throttle response."

It follows that by installing PC the throttle control inputs are going to move the butterfly wider (therefore increase the expected acceleration) than would otherwise be the case for the same rotational throttle input without PC. What isn't in question is the wider the butterfly opens the more fuel is available and the faster the engine will rev/ accelerate.

"Throttle response" in the context of this debate comes down to semantics. Clearly the throttle is more responsive....'twitchy as you put it. In fact PC is designed to make the throttle over respond to an input. It's clear this over responding is very noticeable by riders...your quarter turn is now a three quarter turn (for argument sake).

While you appear (to me) to have a solid argument on how the throttle system works the fact PC makes the bike accelerate further along the slew graph with less rotational input of the throttle is essentially the same thing as the ryker owners with PC are saying...the throttle responds better.....it's a rose by another name.....surely? :riding:

 

[AndysF3S]

A couple of years ago, the trail skidoo riders (Renegade, MXZ models) didn't like doo's electronic throttle because it was tooooo twitchy for a lot of them. Sooo in 2022, Doo changed the throttle from electronic to a cable that goes to a module (variable resistor?) that sends the signal to the ECM which then sends the signal to the throttle body. Baas ackwards IMO, but it is what it is. Reverse engineering at its best.

 

[DickB]

My comment....

"so....Pedal Commander tells the butterfly to open a third of a blink of an eye earlier than would otherwise be the case."

would've been better written... Pedal commander tells the butterfly to open wider than would otherwise be the case?

Given your comment....

"Because Pedal Commander does make the twist grip more sensitive, a small twist of the grip with it will open the butterfly more and thus deliver more power than the same small twist without it. This increase in sensitivity is perceived as improved throttle response."

It follows that by installing PC the throttle control inputs are going to move the butterfly wider (therefore increase the expected acceleration) than would otherwise be the case for the same rotational throttle input without PC. What isn't in question is the wider the butterfly opens the more fuel is available and the faster the engine will rev/ accelerate.

"Throttle response" in the context of this debate comes down to semantics. Clearly the throttle is more responsive....'twitchy as you put it. In fact PC is designed to make the throttle over respond to an input. It's clear this over responding is very noticeable by riders...your quarter turn is now a three quarter turn (for argument sake).

While you appear (to me) to have a solid argument on how the throttle system works the fact PC makes the bike accelerate further along the slew graph with less rotational input of the throttle is essentially the same thing as the ryker owners with PC are saying...the throttle responds better.....it's a rose by another name.....surely? :riding:

No, it’s not a rose by another name. It is throttle response (time) versus input sensitivity (effort or distance) and they are entirely different things, not different names for the same thing. And often confused.

First, addressing semantics, I have been careful and precise in my use of my terms. Others have not.

Some use the term “throttle” to mean the twist grip, and some use “throttle” to mean the butterfly. I have used the terms “twist grip” and “butterfly” to avoid any confusion regarding the meaning of terms.

Misusage of the term “throttle response” has happened in this thread and elsewhere. At the outset I defined throttle response to mean a measure of how quickly a vehicle's engine can increase its power output in response to a driver's request for acceleration. This is the generally accepted definition (https://en.wikipedia.org/wiki/Throttle_response), and in fact is the definition used by Pedal Commander on their website:

“…throttle response is more appropriately referred to as the time speed of increase in levels of power…”​

Note that nowhere in the definition of “throttle response” is there any reference to the amount of effort or the distance required to move an input device to increase power. That is sensitivity.

So when I refer to “throttle response” I'm referring to the time to increase power.

Since the data shows that in stock condition the butterfly can be opened as fast as the throttle body slew rate allows, maximum throttle response (shortest time to increase in power) can be had in stock condition. Pedal Commander does not and can not improve throttle response; to do so would require the butterfly to move faster than it is physically able.

Pedal Commander alters input device (twist grip or pedal) sensitivity. Again, from Pedal Commander’s website:

“It lets you adjust how sensitive your gas pedal is.”​

So yes, if you twist the grip less than 100%, the more sensitive input device is going to cause the butterfly to open more. But this relationship is independent of time, and therefore is not throttle response, it is sensitivity. I have acknowledged that an increase in sensitivity is (wrongly) interpreted by many as improved throttle response.

I have consistently and clearly stated that Power Commander alters sensitivity but does not alter throttle response. I have postulated and then proved with real word Ryker data that if you twist fast, you get the maximum possible throttle response out of a Ryker.

There may be an issue with semantics, but I don’t have that issue.