[Dr.Naren]

Originally Posted by Whiplash7

I'm skeptical with your explanation since by simply adding an offset position you would create a dead-band near 100 percent. It would also make it tough for the driver to control the pedal, since you practically reducing the pedal travel distance which maxes out at a lower pedal position.

What I meant was you would get 100 percent throttle pedal position response at just 50 percent throttle position. This is the reason why car feels faster.

Attaching a pic of simplified driver's wish map :



Now with pedal tune box, it fools the ECU about real throttle position. In a remap these values can be changed directly. There is no fooling business. But even if you make changes, certain values get limited by other maps like torque limiter map, smoke map, boost limiter map etc and these maps are also changed during remap. Pedal tune box doesn't have control over all these maps.

Suppose pedal tune box fools the ECU to request 100 percent throttle position fuel at just 50 percent, Driver would feel very crisp throttle response and more power(Actually he gets fooled ).

Quoting the information about driver's wish map :

Changes to this map make no change to the actual fuel going into the engine. What it really does is only change how much fuel we are asking the ECU to consider injecting into the engine. So why will we change it? Changes to this map will make the car feel more responsive. You can make any changes you want to this map and it will have no potential damage causing alterations to what actually happens in the cylinder of the engine. In your very first map write to an ECU, we will only change this map, then go and drive the car and feel how it has changed. It’s very safe and will be the most apparent change you will see from any map modification.

Oddly there is 2 things we can achieve in this map without changing anything else. Firstly we can fool the car owner into thinking his car is much faster. If we make the map so that our 100% throttle settings are at 50% throttle we will have changed what is called “throttle response”. What you need to consider is not many people actually put their foot flat down on the throttle, and if they do it is for a very short period of time. Make it so that it happens at only 50% and the car will respond quicker, the brain will think the car is faster because it is used to how far we press the pedal and how much acceleration we feel. Additionally when we do accelerate in our standard car, we are used to the acceleration feeling falling away the faster we go, our driver will not be able to separate these 2 known pre-existing feelings (i.e. before we changed the throttle settings) because our brain learns over time how to alter pressure on our foot and the feedback it gets

What's explained here is about driver's wish map and how making changes only in this map actually fools the driver.

Pedal tune box fools the ECU and the driver too.

Instead of this box, press the throttle harder .

Why do you need a box to make you feel 100 percent throttle response at lesser position?? Is it worth??

Source :www.obd2equipment.com

Frank Mehta sir,

I won't say this box is useless for your Crio. But I would never go for this pedal tune box and expect more power. Actually it does the job very well by tricking the driver to believe the car is faster.

I did some research on this box (Google) and many guys abroad have expressed the same opinion.

Since you have access to dyno, please do a comparison. Dyno runs would be done with full throttle, I believe.

This box would make any driver happy. You just need to press lesser and psychological feel of more power.

[McLaren Rulez]

I'm curious why the dyno run shows a performance gain.

If it is doing what Dr.Naren says it is, then it is also creating a dead zone at the last bit of throttle travel. Any chance you can test this out Frank? Drive in normal and race modes with a lead foot and see how it's like?

[frankmehta]

Originally Posted by frankmehta

I must add. I never use 100 percent of throttle. But I know for a fact that at FULL RACING MODE on the remote, there is lesser amount of usable pedal travel. Naturally, after some amount of throttle input, the pedal must be maxing out the signal to the ecu, which means the remaining part of pedal travel (maybe the last 20 percent) is useless at full settings.

I have confirmed that. After a lead footed approach, the last 20 percent of the pedal has no bearing. The first 80 percent constitutes full load. Also, digging your foot down into the floor yields the same results as, say 60 percent throttle in Race mode.

[Dr.Naren]

Originally Posted by McLaren Rulez

I'm curious why the dyno run shows a performance gain.

If it is doing what Dr.Naren says it is, then it is also creating a dead zone at the last bit of throttle travel. Any chance you can test this out Frank? Drive in normal and race modes with a lead foot and see how it's like?

I am not sure about dead zone. I don't think it would be so. Suppose you get 100 percent throttle response much earlier, it doesn't mean there would be no response with further pressing the pedal down. It would be sustained and car will still accelerate.

I had told about 100 percent throttle response with just 50 percent throttle position just for reference. Actual value would be different but the concept is same.

Easy way to compare if there is real power gain is to drive with 100 percent throttle (WOT) and check the difference with and without box.

Originally Posted by frankmehta

I have confirmed that. After a lead footed approach, the last 20 percent of the pedal has no bearing. The first 80 percent constitutes full load. Also, digging your foot down into the floor yields the same results as, say 60 percent throttle in Race mode.

Exactly!! This is what I was trying to explain. This pedal box will make you happy with crisp throttle response but power gain is not convincing.

[McLaren Rulez]

Originally Posted by Dr.Naren

I am not sure about dead zone. I don't think it would be so. Suppose you get 100 percent throttle response much earlier, it doesn't mean there would be no response with further pressing the pedal down.

Yes, what I mean by a dead zone is a region where additional throttle input results in no additional acceleration. Moving the throttle in that region does nothing as confirmed by frankmehta.

[sandeepmohan]

On the subject of how the throttle pedal is linked to the carburettor in older cars, my 72" Fiat uses a metal linkage. I've never seen this before. I'd assume this set up allows for even sharper throttle response and there is no cable to snap. While the engine does respond well, I don't have a way to compare if it actually makes a difference.

For me, the VW GT is a car with good throttle response in Sport mode. The car is peppy and more in its element but it also makes it unsuitable to drive in bumper to bumper traffic. This mode also changes the gearbox response. I guess, a product like PedalTune will reduce or even eliminate some of the lag you experience in D mode.

[frankmehta]

Originally Posted by sandeepmohan

On the subject of how the throttle pedal is linked to the carburettor in older cars, my 72" Fiat uses a metal linkage. I've never seen this before. I'd assume this set up allows for even sharper throttle response and there is no cable to snap. While the engine does respond well, I don't have a way to compare if it actually makes a difference.

For me, the VW GT is a car with good throttle response in Sport mode. The car is peppy and more in its element but it also makes it unsuitable to drive in bumper to bumper traffic. This mode also changes the gearbox response. I guess, a product like PedalTune will reduce or even eliminate some of the lag you experience in D mode.

Bang-on
D mode is dead and tries to save a lot of fuel by shifting early.
I dont mind shifting up early, but the throttle responses in D are not snappy enough. With pedal tune, they're snappy and how! Fuel Efficiency has not taken a hit, and I daresay it may have gone up because I drive at part throttle and it shifts up to d7 much quicker than before. It's something I can't explain in words!

[Dr.Naren]

Pedal tune box will definitely help improve throttle response, no doubt about it. But gain in power is highly questionable. Most of the companies abroad sell pedal tuning box + regular tuning box as a kit. Also this pedal tune box topic has been debated a lot in various international forums.

Conclusion was good throttle response but no actual gain in power.

[Sankar]

It's like the quick throttle I used to have on my tuned RX135 5 speed. Basically when i twist the throttle grip 25% the carb slide would go up by about 50%.

https://www.youtube.com/watch?v=qEcl4ZS1Ixs

https://www.youtube.com/watch?v=kGpNxB8yeqA

Basically the same thing as above but done electronically with on the fly adjustments.

[audioholic]

Most ECUs are learning ECUs. There is no hard map relating acceleration pedal position to throttle position or fuelling. This is the case especially with petrol engines with a physical throttle, not a diesel engine. And this map in the ECU is modified based on the drivers driving habits and the history of how the accelerator has been used. An additional advantage of using this system is that the ECU can also learn how much of the Accelerator pedal is actually working and can calibrate itself now and then. Suppose your accelerator position sensor reports a max of 90% in both the main and sub circuits, the ECU learns that this is the limit your pedal can travel and will map it to the upper limit of throttle position.

If you have been having a hard foot on the throttle, the ECU automatically uses a much more aggressive pattern and this will make the car more responsive. However, if you have been driving sedate, the throttle response is made much smoother and you will feel that the car is somewhat sluggish. This happens in both my drive by wire cars. When my SX4 is driven only in the city with a light foot, and then taken onto a highway, the car accelerates slower, and sometimes requires flooring the pedal. I stop at a signal and recalibrate the throttle, and then it responds like crazy. Once I am back to city traffic, in the first few signal blocks I find it difficult to control the car since the accelerator would be too sensitive. After some time of light footed driving, the car becomes calm again.

At idle or shut off position, the throttle in my Celerio goes all the way to 60 percent with a 10 pecent acc. pedal input. When the car is in motion, this factor reduces, and at medium city speeds, the throttle position doesnt cross 40%, even if accelerator is pressed fully, instead initiating a kickdown. Now this is how they make the car more efficient compared to the non drive by wire WagonR I used to have.

Seeing all this and being an automotive SW developer myself, I dont find this add-on to be really worth it. Its just alters the ECU learning instantly and thats why the difference is felt. However though any number of maps can be customised, the ECU will still relearn the pattern and adapt the way it wants. Again when the mode is changed on Pedal tune, initially the ECU will be a little lost and then after sometime it should relearn the new input it gets from Pedaltune and get back to its usual way of functioning.

From a functional safety point of view, this device in itself is a little risky to use, but again the Accelerator pedal itself has a main and sub circuit for redundancy and any discrepancy in the signal sent between the two will lead to an error. Hence if something really goes wrong with pedal tune, it should be sending the exact wrong values on both circuits, which is a little less probable IMO. But better be safe than sorry. I would never want some unintended acceleration especially with an automatic car. With a manual I wouldnt bother, except for some extra noise and scare to people around me. In an automatic, this will be a little scary, especially if one is not used to emergency handling.

[Whiplash7]

Originally Posted by audioholic

If you have been having a hard foot on the throttle, the ECU automatically uses a much more aggressive pattern and this will make the car more responsive. However, if you have been driving sedate, the throttle response is made much smoother and you will feel that the car is somewhat sluggish. This happens in both my drive by wire cars. When my SX4 is driven only in the city with a light foot, and then taken onto a highway, the car accelerates slower, and sometimes requires flooring the pedal. I stop at a signal and recalibrate the throttle, and then it responds like crazy. Once I am back to city traffic, in the first few signal blocks I find it difficult to control the car since the accelerator would be too sensitive. After some time of light footed driving, the car becomes calm again.

The ECU automatically changing throttle response based on driving behavior sounds dangerous to me. I think that's why all cars come with an interface to manually switch between driving modes like Eco, sport, etc. so that the driver is aware how the vehicle is going to respond to his input. Also wouldn't ARAI have a problem with this since the cars throttle response varies automatically? Whereas if the car has different selectable modes that can be selected then I guess they can test the car in all the modes and check if it passes the emission norms. Somebody who knows the testing procedure at ARAI should be able to throw some light.

Originally Posted by audioholic

At idle or shut off position, the throttle in my Celerio goes all the way to 60 percent with a 10 pecent acc. pedal input. When the car is in motion, this factor reduces, and at medium city speeds, the throttle position doesnt cross 40%, even if accelerator is pressed fully, instead initiating a kickdown. Now this is how they make the car more efficient compared to the non drive by wire WagonR I used to have.

I think this is because normally at idle the ECU is ready to provide instant power since the driver could start moving the vehicle at any time even when uphill and hence the throttle is opening is more to have the air mass ready for sudden power delivery.

[audioholic]

Originally Posted by Whiplash7

The ECU automatically changing throttle response based on driving behavior sounds dangerous to me. I think that's why all cars come with an interface to manually switch between driving modes like Eco, sport, etc. so that the driver is aware how the vehicle is going to respond to his input. Also wouldn't ARAI have a problem with this since the cars throttle response varies automatically? .

What is so dangerous here? There isnt a day and night difference leading to any crash. Just a few cars come with switchable driving modes and in the rest its a normal thing for the ECU to learn the driving behaviour. Same applies for the transmission as well for the DCTs and AMTs. ARAI having a problem with this sounds absurd to me. If I were ARAI I would rather be worried about mandating airbags and ABS and a device to nullify accelerator if the seat belt is not worn rather than mandating how the throttle responds to accelerator inputs.

In a normal car, the learning process happens over a period of time. With this device, you accelerate that process which will make the driver feel an instant difference. Drive two similar cars owned and driven by different people and you will find a difference if they have a drive by wire accelerator. Especially if one is a sedate driver and the other has a hard foot. Nothing dangerous here.

[sukiwa]

Originally Posted by frankmehta

I am talking about something called a PedalTune by TTS Auto, that specialises in modifying German cars, esp Mercs, Audis and VWs in an unconventional manner, with a maturity that we are yet to see in the Indian market.
http://ttsauto.eu/index.php?route=pr...1&product_id=1

Originally Posted by frankmehta

I am extremely impressed with this product. It costs 16k.

Oddly enough, above link is showing product price & shipping cost as 0 € right now, don't know if it's due to some glitch on their website.

[Waspune]

Even racechip has a similar product:

https://www.racechip.eu/accessories/...e-control.html
Racechip recommends using it in conjunction with the Tuning box, which is like double fooling of the ECU

Actually there are several products available in the West that work on the same lines. I feel such products are good for NA cars, as remap gains are not much in them. But for turbo cars, there is nothing better than a proper remap by TOT, WolfMoto and the likes.

After installing the throttle box, I wouldnt be able using the accelerator's full travel range as the max throttle would be delivered much earlier. So, I guess this can be useful for someone who wants to have a crisper throttle response out of the accelerator that has a deep travel, like Fiat Punto/Linea?

[VeyronSuperSprt]

This trick is referred to as the best alternative to prozac.

Don't need to tell you guys why.