Sprint Booster for the 2015 Genesis 5.0

[kaigoss69]

By the way, looks like I'll be going for the Burger Tuning Pedal Tuner, since it is only $179 new and virtually does the same thing, minus valet mode. Good reviews on BMW forums, so what's good enough for BMW is good enough for my Genny.

 

[Jalvin Cohnson]

The way I understand it...

1.) No sprint booster - push pedal all the way down, without engaging kick-down switch = 98% throttle opening
2.) No sprint booster - push pedal all the way down, engaging kick-down switch = 86% throttle opening
3.) With sprint booster - push pedal 50%-100% down (no kick-down) = 98% throttle opening
4.) With sprint booster - push pedal 100% down (engaging kick-down) = 86% throttle opening

This helps except I thought kick-down was automatic, but you are saying there is a switch?

I am learning about kick-down on this thread and I guess I don't fully understand it lol

EDIT: I just watched a video on it and it is a physical switch on the pedal. I don't think my 2012 has that, so I am not sure what changes for me. I do wish the downshifting was a little better when you need the car to give you more power. I am trying to figure out if on a car that doesn't have a kick-down switch, if the SB makes the A/T downshift any faster.

 

[Jalvin Cohnson]

Jalvin,

I am not sure I understand your question completely, but here are my observations.

1. Case scenario before Sprint Booster:

I am driving on a highway at 50 mph in 6th gear with my ZF 6-speed transmission. Another car is driving next to me in the lane on the right. I see ramp ahead and decide that I want to exit highway and go to McDonalds. I have two options:

1. Slow down to 30 mph and get behind that car
2. Speed up (break speed limit traffic rule for several seconds) and go in front of the car.

I choose option #2. So, I press gas pedal half way, nothing happens for about second or two (ECU is thinking), then I feel like transmission shifts from 6th to 5th gear and car speeds up, but not enough to overpass car on the right. So, next I floor the pedal and transmission goes into 4th gear, RPM goes to about 4,500 and car takes off and I am in front of that car and can take exit ramp. And all this may take between 5-8 seconds.

2. Case scenario after Sprint Booster was installed.

The same situation and two options as in case #1.

I choose option #2. So, I press gas pedal half way. Transmission goes into 4th gear, RPM goes to about 4,500 - 5,000 and car takes off like on steroids. I am at 75 mph in a few seconds and I am in front of that car with about three cars length.

So you have noticed faster response and downshifting when attempting a pass? That's neat.

I am just so stuck. Half of me loves the idea, half of me is skeptical. I understand all it does is change the voltage, but changing the voltage isn't the only thing that happens with the car, so I am trying to get a full understand of the Sprint Booster before I choose to buy one or pass on it.

Right now I am leaning towards getting it because the base model 2012 Sedan I have doesn't come with driving modes like Eco, Sport, etc..., so it would add that benefit for me, on top of a quicker throttle response from 50-100% pedal down being eliminated.

Also, could you go into further detail how the downshifting feels/works with and without the SB? It seems to me in your explanation, another benefit is better downshifting for A/T.

 

[AgentSmith007]

So you have noticed faster response and downshifting when attempting a pass? That's neat.

Yes.

Also, could you go into further detail how the downshifting feels/works with and without the SB? It seems to me in your explanation, another benefit is better downshifting for A/T.

Downshifting without SB is smother. Downshifting with SB is little bit more aggressive. This how it feels to me.

 

[Jalvin Cohnson]

Yes.


Downshifting without SB is smother. Downshifting with SB is little bit more aggressive. This how it feels to me.

Thank you for confirming!

 

[carguy75]

If I am understanding you correctly, as long as you push the gas pedal to 50%+, but not all the way down, is where you get the best performance? Because this would go around the kick-down, while at the same time giving you a throttle that opens 12% more? If this is true, than you may have finally made my mind of up for me.

Correct.

 

[carguy75]

The way I understand it...

1.) No sprint booster - push pedal all the way down, without engaging kick-down switch = 98% throttle opening
2.) No sprint booster - push pedal all the way down, engaging kick-down switch = 86% throttle opening
3.) With sprint booster - push pedal 50%-100% down (no kick-down) = 98% throttle opening
4.) With sprint booster - push pedal 100% down (engaging kick-down) = 86% throttle opening

Pretty much that is the sum of it. Except that I believe that you will always activate the kickdown in stock form if you press the gas pedal all the way down, therefore you will never get a 98% throttle opening without a throttle module like the Sprint booster or Pedal Commander.

I assume that Hyundai only allows the throttle to open 86% to prevent a driver from losing control since 420hp is a lot of power for an average driver to control all at once especially on the stock grand touring allseason tires.

The Sprint Booster makes controlling the Genesis during hard acceleration a white knuckle affair without a doubt.

The kick-down restriction also explains why the 2015 Genesis posted some slow 0-60 times(5-5.2 seconds) from the auto magazines since they all floored the gas pedal in the acceleration test. This car is a 4.5 second 0-60 easy with a pedal tuner and good launch.

 

[carguy75]

Now I have a question that can only be answered from a Hyundai engineer or a chassis dyno. Is the Genesis 420hp horsepower rating based on the results of the throttle-by-wire tuning that restricts the throttle to open only 86%.

If so what would the power rating be for the engine with a full 98% throttle opening?

Current SAE guidelines requires manufacturers to publish the horsepower generated in the final consumer configured automobile including a rating for the lowest octane recommended to use. Therefore, this engine is probably making more than 420hp when the throttle is allowed to be fully opened pass 86%.

 

[edizzle89]

Now I have a question that can only be answered from a Hyundai engineer or a chassis dyno. Is the Genesis 420hp horsepower rating based on the results of the throttle-by-wire tuning that restricts the throttle to open only 86%.

If so what would the power rating be for the engine with a full 98% throttle opening?

Current SAE guidelines requires manufacturers to publish the horsepower generated in the final consumer configured automobile including a rating for the lowest octane recommended to use. Therefore, this engine is probably making more than 420hp when the throttle is allowed to be fully opened pass 86%.

you also have to remember that 420 hp number is at the crank, which means it was probably measured on an engine dyno so there was no actual 'gas pedal' being used so the kickdown switch probably wasnt a problem. I would guess that 420 hp at the crank is at full wide open

 

[carguy75]

you also have to remember that 420 hp number is at the crank, which means it was probably measured on an engine dyno so there was no actual 'gas pedal' being used so the kickdown switch probably wasnt a problem. I would guess that 420 hp at the crank is at full wide open

The old method allowed by SAE(pre-2006) let automakers publish horsepower numbers on an engine dyno without the other devices that would limit the power output in the actual vehicle such as stock exhaust, accessories, ecu control tuning, etc. Therefore, cheating customers in many cases by stating an engine provides a certain amount of power that it did not in the real world.

After 2006 per SAE, automakers had to publish the actually horsepower made by an engine with the same accessory and calibration as it would sold to the consumer. Therefore, the Genesis by law should be making 420hp with only opening the throttle to 86% like it does in the end product sold to us.

Hyundai should not dyno the engine and publish the power obtained from a 98% throttle opening that the engine will not provide in stock form due to the factory calibration that limits it to only 86% which would lower the power output.

I believe the 420hp rating is with the stock maximum 86% throttle opening. The power output should be more if the throttle is actually tricked into opening to 98% with throttle voltage tuners like Sprint booster and Pedal Commander.

The throttle tuner module results is similar to how piggyback tuner modules fool the ECU of stock turbo cars like the G80/70 3.3T to create more boost due to altering the signals to the ECU about sensor readings. Same concept. I am surprised that my Sprint Boost may actually provide more horsepower by letting my engine fully breath due to opening the actual throttle plate more that stock.

I will try to use my scan tool to log some actual data from my Genesis to see if the throttle actually opens to 98% with the Sprint Booster and if the throttle actually closes during WOT to 86%. I may have to look at the throttle voltage if my scan tool does not have the exact throttle plate opening position data and see the difference by comparing the voltage to the chart provided by Hyundai I posted.

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[kaigoss69]

I do not think that you have to do any tricks to get 98% throttle opening. Push the accelerator all the way down without engaging the kick down switch!

 

[carguy75]

My Autel Maxidiag Elite does have throttle position data including voltage. I just tested it. However, I also noticed that my 5.0 does have torque management for the transmission which does restrict torque.

I will use my scanner to do some runs with and without the Sprint Booster activated to see if it does really makes an difference to the throttle voltage and position.

My scanner tool, very useful for DIYer like myself.


Here is some throttle data and the torque management data

 

[carguy75]

I do not think that you have to do any tricks to get 98% throttle opening. Push the accelerator all the way down without engaging the kick down switch!

Refer to post#31

The kick-down happens when the pedal is fully floored at 4.41 volts which is a max 86% opening. Over 86% opening needs more than 4.41 volts to occur. Remember, the stock pedal increase voltage as you press the accelerator pedal down in linear fashion.

I do not see how you can fully open the throttle without engaging the kick down switch to achieve a higher voltage in stock form. Sprint booster does trick the system by applying over 4.41 volts before making contact with the kick-down switch, hence fooling and bypassing the 86% max limit set by Hyundai.

 

[kaigoss69]

Refer to post#31

The kick-down happens when the pedal is fully floored at 4.41 volts which is a max 86% opening. Over 86% opening needs more than 4.41 volts to occur. Remember, the stock pedal increase voltage as you press the accelerator pedal down in linear fashion.

I do not see how you can fully open the throttle without engaging the kick down switch to achieve a higher voltage in stock form. Sprint booster does trick the system by applying over 4.41 volts before making contact with the kick-down switch, hence fooling and bypassing the 86% max limit set by Hyundai.

My theory is based on logic. I could be wrong, but:

- The Sprint booster does not amplify the voltage output from the stock pedal, it only changes the delivery curve, so the voltage rises faster
- if the SB outputs a voltage that results in 98% throttle opening, it had to “learn” that voltage from the calibration procedure.
- therefore there is a position on the stock pedal that creates 98% throttle opening, and logically it would be at the position just before the kick down switch is engaged
- The kick down is normally a mechanical switch that requires extra force to engage, so if you are careful you can reach the resistance point without triggering the kick down (that’s how it worked in my previous car and I am assuming the Genesis has the same system)

 

[edizzle89]

Refer to post#31

The kick-down happens when the pedal is fully floored at 4.41 volts which is a max 86% opening. Over 86% opening needs more than 4.41 volts to occur. Remember, the stock pedal increase voltage as you press the accelerator pedal down in linear fashion.

I do not see how you can fully open the throttle without engaging the kick down switch to achieve a higher voltage in stock form. Sprint booster does trick the system by applying over 4.41 volts before making contact with the kick-down switch, hence fooling and bypassing the 86% max limit set by Hyundai.

but if you look at post #31 you'll also see that Hyundai does reference that 98% max throttle, so i'd assume it is capable of being achieved in stock formm from having the pedal as far down as possible without hitting the kickdown switch, you can see where they specify voltage at 98% which is 4.65v then reference WOT. I assume when the kickdown switch is pressed the ecm is what bumps the voltage down to cut it back to 86%/4.41v.

which makes sense since the physical pedal movement just before the kickdown is probably about 98% then the last 2% of throttle movement is what presses the kickdown. but using a scantool would verify all this.

 

[carguy75]

but if you look at post #31 you'll also see that Hyundai does reference that 98% max throttle, so i'd assume it is capable of being achieved in stock formm from having the pedal as far down as possible without hitting the kickdown switch, you can see where they specify voltage at 98% which is 4.65v then reference WOT. I assume when the kickdown switch is pressed the ecm is what bumps the voltage down to cut it back to 86%/4.41v.

which makes sense since the physical pedal movement just before the kickdown is probably about 98% then the last 2% of throttle movement is what presses the kickdown. but using a scantool would verify all this.

So you believe that the engine is allowed to go full throttle (98%) and then back down to part throttle(86%) in stock calibration when the WOT switch is pressed. Interesting theory, but I do not think that it is actually how any automaker would design a throttle system to work. I believe the kick-down switch is positioned in such a way that prevents the stock throttle to achieve the mechanical 98% opening limit.

Hence the actual operation range being 0-86% per the diagram even if the throttle can physically open to 98%.

Edit: I just check some facts about kick-down switches and you may be correct. You could probably go full throttle in stock form without pressing the kick-down. I stand corrected.

 

[carguy75]

My theory is based on logic. I could be wrong, but:

- The Sprint booster does not amplify the voltage output from the stock pedal, it only changes the delivery curve, so the voltage rises faster
- if the SB outputs a voltage that results in 98% throttle opening, it had to “learn” that voltage from the calibration procedure.
- therefore there is a position on the stock pedal that creates 98% throttle opening, and logically it would be at the position just before the kick down switch is engaged
- The kick down is normally a mechanical switch that requires extra force to engage, so if you are careful you can reach the resistance point without triggering the kick down (that’s how it worked in my previous car and I am assuming the Genesis has the same system)

The Sprint Booster module is just an adjustable voltage booster that increase the voltage of the accelerator pedal signal hence reducing the curve. The throttle-by wire system input is based on voltage to determine the throttle opening in which the Sprint Booster just modify to adjust the throttle opening. The increase in voltage is what makes the drive-by wire system respond quicker to input since it reduces the time it take to fully open the throttle body compared to stock.

The time it takes to fully floor the gas pedal and engage the kick-down in stock form requires more time than just pressing the pedal half-way to gain full throttle with the Sprint Booster hence the reduction in acceleration times. Furthermore, Hyundai system of partial open WOT throttle actually allows the Sprint booster to provide addition performance gains by fully opening the throttle with just a half press of the gas pedal.

Edit: The engine may be able to open the throttle fully to 98% without the Sprint Booster since it may be possible to go full throttle without pressing the kick-down switch.

 

[edizzle89]

yea automakers do weird stuff with electric throttles. we verified basically the same thing in my buddies ram truck, whatever year it was that they started putting the 5.7 hemi's in them. at 100% pedal the throttle was around 80-85% where having the pedal at around 85-90% it would open the throttle to around 95%, you could actually feel the difference.

 

[carguy75]

yea automakers do weird stuff with electric throttles. we verified basically the same thing in my buddies ram truck, whatever year it was that they started putting the 5.7 hemi's in them. at 100% pedal the throttle was around 80-85% where having the pedal at around 85-90% it would open the throttle to around 95%, you could actually feel the difference.

Makes sense. The kick down is actual used to tell the transmission to drop gears for passing or pulling hills, so it make sense that is also closes the throttle as well to prevent redlining the engine when going into a lower gear.

 

[Jalvin Cohnson]

Someone correct me if I am wrong, but I want to make sure I understand correctly.

To reach 98% open throttle WITHOUT Sprint Booster, you have to press the gas all the way down WITHOUT activating the kick down. This is difficult because 100% full throttle and the kick down switch are very close to each other, so you would have to get incredibly good at pressing the gas pedal all the way down, but without activating the kick down. This means you actually aren't pushing the pedal all the way down, but 99% of the way down.

To reach 98% open throttle WITH Sprint Booster, all you have to do is push the gas pedal down in the 50-99% range, since full throttle is at 50%. This is much easier to achieve with the additional room you have in the second half of the pedal. This means that the Sprint Booster makes it easier for drivers to get a wide open throttle without activating the kick down.


If the 2 paragraphs above are true, I may be ordering one myself. I have the base model 2012 3.8 sedan, which did not come standard with driver modes like Eco, Sport. etc... That benefit, along with the Valet and Lock mode, AND the easier access to the 98% open throttle, would make the purchase totally worth it.