Accelerator pedal/throttle position sensor output

[chrev]

Has anyone put a scanner on their car and noticed the throttle position sensor percentage when at WOT? While out enjoying a quarantine induced ride I noticed that if I floored both the accelerator pedal sensor and the throttle position sensor maxed out at 87.1. When at idle it is at 14.9ish. Can anyone confirm if the 87.1 is an expected value?

 

[NSXNEXT]

Sprint Booster for the 2015 Genesis 5.0

 

[chrev]

Thanks for the reply.

 

[chrev]

For everyone with the 1G V8 I did some testing and no matter what I do the TP% never goes above 87. If I get it the pedal just touching the kick down button the TP only goes to 82. The max accelerator pedal reading I could get was 83 and that was after the kick down button was pressed. Putting it in "sport mode" and turning off ESC makes no difference. There are posts about this on the sprint booster page but this information gets lost in the discussion. It appears that 100% throttle opening cannot happen reliably without manipulating the voltage.

 

[Suburbazine]

Why would you want the throttle plate to open to 100%? That only causes turbulence in the manifold and decreases scavenging. The 87% mark is about as wide open as you can go at WOT without decreasing performance. Also, don't let anyone BS you into believing that a pedal modifier will change the opening angle of the TPS (on a 2nd Gen, the 1st Gen is different I hear). It only alters the ratio between the TPS and APS. The video below will show you opening to 100%- but that's only with the engine off. The maximum angle is altered by manifold pressure, RPM and cam advance.s

 

[carguy75]

Why would you want the throttle plate to open to 100%? That only causes turbulence in the manifold and decreases scavenging. The 87% mark is about as wide open as you can go at WOT without decreasing performance. Also, don't let anyone BS you into believing that a pedal modifier will change the opening angle of the TPS. It only alters the ratio between the TPS and APS. The video below will show you opening to 100%- but that's only with the engine off. The maximum angle is altered by manifold pressure, RPM and cam advance.

I used my Autel Scan tool to look at the throttle position and throttle opening with the Sprint Booster activated in Sport and ECO drive mode recently; and the throttle opening was about 92 percent with me just pressing the gas pedal part way or near half in which it was read as throttle position 100%. So the Sprint Booster voltage manipulation method does causes the throttle plate to open pass 87 percent and the pedal position to be read as 100% even if it is only pressed about halfway down.

My Genesis did not have any performance issues with a 92 percent throttle opening. I will try save a log and download it on the forum when I test it again with my scan tool. It is tough using the scan tool and driving at the same time so I did not see the entire log as I tested it, but I will record and post a log.

Note: I believe that throttle body plate can physically only open to a max 96% by design.

 

[carguy75]

Has anyone put a scanner on their car and noticed the throttle position sensor percentage when at WOT? While out enjoying a quarantine induced ride I noticed that if I floored both the accelerator pedal sensor and the throttle position sensor maxed out at 87.1. When at idle it is at 14.9ish. Can anyone confirm if the 87.1 is an expected value?

I have not tested my car stock, but with the Sprint Booster I have noticed that it can go up to about 92% on my Autel scan tool live data scan. 86% is supposed to be the stock limit based on the kick down and travel range of the accelerator pedal that is limited by the kick-down switch on the pedal mechanism itself, so 87% is within tolerance. However, in theory a pedal booster can supply enough additional voltage before activating the kick-down switch to allow the throttle to open pass 86% even with 1/2 pedal travel.

The stock pedal accelerator pedal regulates the voltage that controls the throttle body controller and is tuned to increase voltage more towards the bottom of pedal travel which cause some delay. Pedal boosters just double or triple the voltage so the throttle opens much sooner on the pedal travel which just bypasses the kick-down unless the gas pedal is pressed to the max position.

Here is a diagram of how voltage and the throttle plate opening relate to each other per Hyundai. WOT kick-down occurs at a max 4.41v on the stock accelerator pedal calibration, however the throttle body can read up to 4.65v by design. Pedal boosters allows the pedal to send a 4.65v signal before activating the kick-down section of the accelerator pedal.




I will post some logs from my Autel scan tool soon.

 

[carguy75]

Tonight I did a quick generic OB2 log with my Autel scan tool which shows the basic graph for the throttle body position (TP )sensor and accelerator pedal sensors. The basic graph does not include the TP voltages.

I did not do a full throttle acceleration run due to police patrolling near by, however the graphic does show that my throttle body opened to 77.6 percent by only pressing the gas pedal about 15% with the Sprint Booster activated in ECO drive mode. Therefore, if I press the gas pedal 50% or more then the throttle will open to 90% or more. I will post log of a full throttle run when the police is not present.

TP is the throttle body opening percent. TP_R/TP_B are the accelerator voltage percentages. APP_D/APP_E are the accelerator pedal positions.

 

[Suburbazine]

You know kickdown switch/section doesn't exist, correct? It's simply a voltage output measurement of the APS with a little clicky nub to make you feel like you're hitting a kickdown switch. The fact that you're reaching over 4.41 with a pedal booster means you're hitting kickdown before you hit the kickdown clicky.

I think you're also confusing APS voltage correlation to TPS voltage. The pedal is not connected to the TPS and there is no "throttle body controller"- you're referring to the ECM. The magic happens in a software function inside the ECM- and a pedal modifier only alters the input to a software table. TPS1 and TPS2 are fail-safe equivalent measurements for each other (to verify accuracy), the same for APS1 and APS2.

 

[carguy75]

You know kickdown switch/section doesn't exist, correct? It's simply a voltage output measurement of the APS with a little clicky nub to make you feel like you're hitting a kickdown switch. The fact that you're reaching over 4.41 with a pedal booster means you're hitting kickdown before you hit the kickdown clicky.

I think you're also confusing APS voltage correlation to TPS voltage. The pedal is not connected to the TPS and there is no "throttle body controller"- you're referring to the ECM. The magic happens in a software function inside the ECM- and a pedal modifier only alters the input to a software table. TPS1 and TPS2 are fail-safe equivalent measurements for each other (to verify accuracy), the same for APS1 and APS2.

View attachment 28633
View attachment 28632

I admit that I may not know the exact function of the throttle-by wire system such as the (click) mechanism, but the outcome is the same it appears regardless of the exact operation explantation.

However, I will need to log a full test that includes voltages to establish if the Sprint Boost really allows the throttle plate to open past 86%(stock WOT limit) due to additional voltage transmitted from the acelerator assemby. I am now very curious if the Sprint Booster really allows the throttle to open pass the stock WOT limit or it just hit the WOT limit much sooner. I test tomorrow.

Note: There is a electronic throttle body controller; the ECU which controls every aspect of the engine operation based on sensor data.

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[Suburbazine]

The ETC is just two sensors and a PWM driven motor. There's nothing else inside besides some gears:


Also, WOT maximum value is dependent on manifold air pressure, RPM and cam advance- so that 86% number on the chart is considered slightly variable. If you're testing, I would recommend logging those values (I'd recommend disabling extra values as they will decrease the polling rate of the scan tool somewhat).

 

[Kraig Wilkinson]

The ETC is just two sensors and a PWM driven motor. There's nothing else inside besides some gears:
View attachment 28635

Also, WOT maximum value is dependent on manifold air pressure, RPM and cam advance- so that 86% number on the chart is considered slightly variable. If you're testing, I would recommend logging those values (I'd recommend disabling extra values as they will decrease the polling rate of the scan tool somewhat).

A guy can learn a lot by reading your post's Suburbazine!

 

[Kraig Wilkinson]

A guy can learn a lot by reading your post's Suburbazine!

If you ever have any questions about a 15L Big Block cummins or a C15 Cat give me a shout .

 

[chrev]

I dont necessarily want it to hit 100% but I was wondering what effect sprint booster would have on it and how fast it goes from closed to "fully open". I wish someone would put this motor on a dyno and test how it responds to mods that increase air flow.

 

[Suburbazine]

I dont necessarily want it to hit 100% but I was wondering what effect sprint booster would have on it and how fast it goes from closed to "fully open". I wish someone would put this motor on a dyno and test how it responds to mods that increase air flow.

It won't increase the maximum actuation rate of the throttle blade- that's already operating at maximum speed. It will shorten whatever time it takes you to stomp the pedal by scaling the input to max at 1/4 travel on the pedal. Your greater delay will be in the TCM as it delays first downshift (and by extension torque demand via throttle angle) for a moment to verify shift strategy.

Air flow mods will slightly improve performance- but changing up the induction tract will only net differences inside the margin of error for any dyno. Your bigger gains will come from combining intake and exhaust improvements, as the exhaust is far from optimal.

 

[carguy75]

I dont necessarily want it to hit 100% but I was wondering what effect sprint booster would have on it and how fast it goes from closed to "fully open". I wish someone would put this motor on a dyno and test how it responds to mods that increase air flow.

Well, tonight on my way to work I tested how long it takes to hit full throttle(100%) per the Autel tool and logged it. I am at work now so I will review the logs when i get home.

With the Sprint Booster activated set to Race level 9 in Eco and Sport mode; the throttle opening was 100% with just a 1/4 press of the gas pedal(or slightly more). I was assuming that it needed to be press halfway with the Sprint Booster, but only just part way gave a 100 percent throttle opening.

However, the throttle read 100% even with the Sprint Booster deactivated with full throttle runs in ECO and Sport mode. Yet, it did require a longer push of the pedal for a WOT run. So based on the live data I read , the throttle opens 100% even in stock form per the tool data. I will look at TPS voltage data later to see if the Sprint Booster actually provides voltages that are more than the 4.41v needed for stock WOT. I also noticed that WOT occurs without having to activate the knockdown(clicker) on the gas pedal when the Sprint Booster is deactivated.

With that being said, I do not know if the Sprint Booster is really completely deactivated if it still connected to the pedal assembly or if the stock throttle-by-wire need to be re-calibrated to stock settings after the Sprint Booster affect on the throttle position; hence the aggressive pedal even the booster turned off.

 

[carguy75]

The ETC is just two sensors and a PWM driven motor. There's nothing else inside besides some gears:
View attachment 28635

Also, WOT maximum value is dependent on manifold air pressure, RPM and cam advance- so that 86% number on the chart is considered slightly variable. If you're testing, I would recommend logging those values (I'd recommend disabling extra values as they will decrease the polling rate of the scan tool somewhat).

Yes, throttle bodies in general are fairly simple devices. The one in our car just uses an electric motor that moves the throttle plate based off voltage as opposed to a older cable assembly throttle body that moves the throttle plate to the open and close positions based off cable tension.

I decided to just log all the values read by the ECU to get a picture how it operates overall. I am not an engineer, but I am curious about torque demand/reduction values and cam advance/retard timing as well as the throttle data.

 

[carguy75]

Well, here the log of the quick run I made to 100mph on the highway with the Sprint Booster set Race level 9 and the Genesis in Sport drive mode. The throttle did open to 100%, however the voltages were well below the Hyundai chart for WOT for the throttle body. I used the Hyundai specific module interface on the Autel scan tool which shows a lot more detailed values seen by the ECU.

I admit that I do not really understand how these numerical values actually relate to how the Sprint Booster does it job, but it does work. The throttle max out with just a slight press of the gas pedal in the highest level the Sprint Booster can set to. I am sure that the device is configured in such a way that it is probably more than a crude voltage booster and has some tuning that does not trigger any fault codes.

I am sure someone will be able to decipher my logs and maybe educate us on how the Sprint Booster does what it does. From what I get out of the log, the Sprint Booster allows the throttle to open fully at only about a 1/10 pedal travel (11.6%) and therefore increases the performance by reducing the time it takes for the engine to accelerate compared to the stock throttle programing.

 

[Suburbazine]

The Sprint booster (like most of its kind) is not a crude voltage booster. It takes the APS1 and 2 sweeps and recalculates them to a different proportional output level. But it's not just a linear amplification, it uses multiplicative boost over time formulae to generate a "surge" output signal when the input signal changes. So rather than a flat 2-5x multiplier, the initial 2 seconds may be a 5x multiplier ramping down to a 2x multiplier. This is what makes the booster feel, well, like a booster- a flat gain doesn't feel very thrilling.

As far as the logging goes, a graph-type log would be much more useful than frame logs. Can your tool do graphing? I'm not seeing useful data from those pictures, aside from the fact that you have a minor intake restriction at WOT.

 

[carguy75]

The Sprint booster (like most of its kind) is not a crude voltage booster. It takes the APS1 and 2 sweeps and recalculates them to a different proportional output level. But it's not just a linear amplification, it uses multiplicative boost over time formulae to generate a "surge" output signal when the input signal changes. So rather than a flat 2-5x multiplier, the initial 2 seconds may be a 5x multiplier ramping down to a 2x multiplier. This is what makes the booster feel, well, like a booster- a flat gain doesn't feel very thrilling.

As far as the logging goes, a graph-type log would be much more useful than frame logs. Can your tool do graphing? I'm not seeing useful data from those pictures, aside from the fact that you have a minor intake restriction at WOT.

What intake restriction are you referring to on the log? And how did you come to that conclusion? Do you have a graph/log with a TAU 5.0 V8 intake that is not restricted at 100mph so that I can compare?

Note: A typical MAP sensor will read 90-98 kPa under full load, my engine was running 94.57 kPa(945.7hPa converted). So if you are refering to the MAP sensor data then you are wrong about an restriction. However, the stock 5.0 air-boxes does have small inlet holes that feed into the bumper area so the engine could breath a bit better I suppose.