Throttle response improvement : Steeda throttle body spacer or BBK Throttle body ?

[5LITERV8]

OK, that's interesting. So you are saying that the factory throttle signal is good but the stock tune limits the available torque until you go WOT? I have never seen the actual signal/data behind it so I would know any different. So what's the reason behind this? Higher MPG when tested? Lower emission when tested?

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[Bluemustang]

OK, that's interesting. So you are saying that the factory throttle signal is good but the stock tune limits the available torque until you go WOT? I have never seen the actual signal/data behind it so I would know any different. So what's the reason behind this? Higher MPG when tested? Lower emission when tested?

I don't have any idea how it works. I've been told that these are torque based ECUs and that Ford has a fair amount of limiting on the torque in the stock tune. When I asked Lund about the throttle tables, they told me that they do not change the ETC tables in the tune. But the changes to the torque tables in the DBW increases the responsiveness. And you feel this in the pedal feel as well.

If any if this inaccurate I apologize. But my point is that the throttle tables don't change and don't need to be changed. Whether Lund is talking about the same thing or not, I do not know. I just know enough to know it's the tune not the throttle demand.

I've used the Bama race tunes as well and I felt a noticeable difference. I could rip the tires around the corner where I couldn't before. It wasn't traction control I'm sure of that because it was the same sensation with or without it.

 

[jonrjen]

So, did I make a big mistake? I ordered the PedalMax with the remote controller knob earlier today. I'm not really disappointed with my GT, but figured what the heck if I can bring on the power quicker, well then let's bring it on.
I ordered the PedalMax with the remote knob and got it for $245 plus change. Did I just blow $245

 

[BmacIL]

Those videos prove nothing. There's no PCM in the test setup. The lack of a representative control module in between the throttle body and pedal invalidates the test setup. Whatever they're using is simply a pass through and not a control module that interprets the signal and sends what it is calibrated to do based on input (and THAT is something your tuner can adjust). I'm expecting a witty salesman retort as usual but I'm leaving it to the smart, critical thinkers to see through the hype. I'll tag an expert and former calibration engineer for a big race team to add more, @jbird60.

So, did I make a big mistake? I ordered the PedalMax with the remote controller knob earlier today. I'm not really disappointed with my GT, but figured what the heck if I can bring on the power quicker, well then let's bring it on.
I ordered the PedalMax with the remote knob and got it for $245 plus change. Did I just blow $245

Probably, unless you like having an on off switch for a throttle pedal, then by all means you'll like it. I don't know a single person using these who competes in a road course environment where both throttle response and more importantly, modulation, are key to going fast with confidence.

 

[5LITERV8]

So, did I make a big mistake? I ordered the PedalMax with the remote controller knob earlier today. I'm not really disappointed with my GT, but figured what the heck if I can bring on the power quicker, well then let's bring it on.
I ordered the PedalMax with the remote knob and got it for $245 plus change. Did I just blow $245

I think you will like it. The issue I had with it is when you take it on to the track or if you are doing any type of high performance driving where you need to modulate the throttle. Before I got the adjustment knob the signal was 100%. Once you hit the apex in the corner it was very difficult to apply the right amount of throttle input to get the max corner exit speed as the pedal feels more like on/off. Once I got the knob I found myself turning it almost all the way down when on the track. Also I have to note that I am not the best driver in the world so maybe that played a role as well .

For the street driving pedalmax is great compared to stock. If that's where you intend to use the car I think you will be happy with it. You will learn how to drive it with the on/off pedal feel.

I would agree with that as well.

 

[Bluemustang]

What I don't understand about it is why would you let a $200-300 device be in control of your throttle response? Why risk a $35k car.

Real modifications are a different story altogether. A tune is one example of a real Performance increase you can feel and isn't a trick. An intake manifold, headers, injectors, superchargers, turbos. Those are real modifications. This is a toy in comparison to the ECU programming that goes into your $35k Mustang.

If you want to keep it stock then keep it stock. But don't mess with a cheap device that isn't going to help you. Throttle modulation isn't just for going fast but it's for safety too.

 

[Nagare]

@BmacIL have you tried one by any chance? A lot of people that haven't tried it talk down on them. I know my car is no faster than before, but it makes driving much more pleasurable for me until I get a tune. Could be similar to an "on/off switch" but that also matches my general driving style where I want to get up and going, not cruise at 35 in a 50.

I almost want to take it out and send it your way just so that you can give it a fair chance instead of only looking at the technical side (I know you're in engineering so it might be hard!) that says it amps the signal up.

@jonrjen definitely let us know what you think when you get it installed. Worst case, it was a waste of a half hour total of your time (install, test drive, uninstall) and you return or sell it. Best case, it is like me where it is a noticeable improvement and you take it for granted after awhile.

 

[BmacIL]

@BmacIL have you tried one by any chance? A lot of people that haven't tried it talk down on them. I know my car is no faster than before, but it makes driving much more pleasurable for me until I get a tune. Could be similar to an "on/off switch" but that also matches my general driving style where I want to get up and going, not cruise at 35 in a 50.

I almost want to take it out and send it your way just so that you can give it a fair chance instead of only looking at the technical side (I know you're in engineering so it might be hard!) that says it amps the signal up.

@jonrjen definitely let us know what you think when you get it installed. Worst case, it was a waste of a half hour total of your time (install, test drive, uninstall) and you return or sell it. Best case, it is like me where it is a noticeable improvement and you take it for granted after awhile.

I've had a device just like them on a previous car. I know what it does and feels like. Yeah, it makes it feel punchier and I guess that's what people want, but it also makes it so that you can't drive with precision and varying throttle all that well. I took it off and pushed the pedal down more when I wanted to get going . That car was never tuned either.

With the Mustang, I think the perception of speed (lack thereof in the S550) plays a big role in people's feelings about this. It's so refined that it feels slower than it is, despite the speedometer. I'm simply trying to help educate based on the facts. Anecdotal experience with a product like this doesn't trump knowledge of the systems controlling the engine.

 

[Nagare]

I've had a device just like them on a previous car. I know what it does and feels like. Yeah, it makes it feel punchier and I guess that's what people want, but it also makes it so that you can't drive with precision and varying throttle all that well. I took it off and pushed the pedal down more when I wanted to get going . That car was never tuned either.

With the Mustang, I think the perception of speed (lack thereof in the S550) plays a big role in people's feelings about this. It's so refined that it feels slower than it is, despite the speedometer. I'm simply trying to help educate based on the facts. Anecdotal experience with a product like this doesn't trump knowledge of the systems controlling the engine.

Nah mine's actually slow so I try to get as much fun out of it as I can ;) The feeling of being punchier is what I wanted so it met my expectations of the device and stopped me having to floor it all the time. With the learning that the car does, it has seemed to tone back after awhile so progressively going further on the pedal does bring about more response instead of being full off/on.

 

[jonrjen]

Well, I guess time will tell. Either I will be impressed, or I won't. At the moment I'm thinking positive that It (PedalMax) will deliver what I expect.

I"m a retired "Old Fart" who purchased the GT as a fun toy, nothing less, nothing more. I don't drag race, don't time race the course. I do enjoy driving the back road twisties here near the house. Also have plans to take it on a few road trips such as Route 66, Pikes Peak as well as a few others. Not to mention that my grandkids love it.

If this delivers more of a "On/Off" feel as to power delivery that is just fine with me. If I find the need to tune down the impact of pedal pressure I'll twist the knob an do so. With our other two vehicles being both boosted (2013 F350 6.7 PSD DRW 4X4, 2013 Taurus SHO) I am well aware of turbo lag and like the feel of more instantaneous results of pedal application.

I will come back and post my impressions once I receive it, install it, and give it a go.

My apologies to the Original Poster, I did not intend to side track your posting in any manner.

 

[jbird60]

Against my better judgement, I'll wade into this discussion...

Every modern production engine control unit (and most of the high-end motorsport controllers) runs on a torque model. What this means is that the driver's accelerator pedal position is taken as a demand for X% of maximum available torque at a certain engine speed (e.g. 20% pedal at 3000 RPM translates to a demand of 18% of maximum available torque, or 40% pedal at 4000 RPM translates to 50% of maximum available torque... note, not real numbers, just providing hypothetical examples). All of this is calibrated in the PCM under what's commonly referred to as Driver Demand Tables.

Pedcurve

• jbird60
• Nov 27, 2018

The blue line above is what @BmacIL referred to as a positive exponential curve (again, note... made up numbers, ignore the values and focus more on the curve shapes). This is what's calibrated as-stock in our cars and is very commonly used in race cars as well. The lower end is flattened out so that there's a bit more sensitivity at low pedal travel (safety first) and the upper end is flattened so that bumps that might make your foot bounce on the pedal don't cause sudden changes in torque. The rest of the curve is pretty much entirely above what would be a linear pedal response (red line).

It's worth noting that your pedal position isn't the only thing that affects throttle position. Other control systems (transmission control for automatics, traction control) all feed into the torque model and are compared to your pedal position to create a final torque demand output. These factors plus the non-linear pedal curve that is usually RPM-dependent means that your pedal position almost never correlates 1:1 with your throttle blade angle.

The green line is what's happening when you use a pedal signal modification device. Note, the y-values (torque demand) on the green line are the same as the stock blue curve, but they're shifted to the left (i.e. they occur with less pedal travel). So basically, whereas on a stock pedal you might press it 60% to get 80% of maximum-available torque, now with a pedal device, you're only pressing the pedal about 37% for the same amount of torque... hence, the on-off switch effect. More importantly, what this means is that the device doesn't make your pedal response linear. Rather, it does the exact opposite... it makes it more exponential.

Now, for some semantics

The term "throttle response" gets thrown around a bunch, but it we don't always attribute it to the right things. The idea of the throttle not opening quick enough when you mash the go pedal is really a thing of the past at this point. We don't use cable throttles anymore (linear, 1:1 pedal to throttle angle) and just about every electronic throttle system uses some variant of a positive exponential response. That delay you may feel/be dissatisfied with is the slow increase in air mass flow and/or fueling mass going into the engine. These can only be resolved with revised intake geometries, improved fueling technologies (direct injection), or better PCM calibration.

Finally, use cases. For many, I can still see a pedal signal modification product as being a fun add-on. Yes, it'll give a sensation of quicker pick-up, but as many have noted, it won't improve the performance of the car, and in the grand scheme of things, it really does reduce your ability to control the car. Having the full pedal travel to modulate engine torque is the safest and most precise way to get the maximum potential out of your engine in high-performance driving environments (drag strip, AutoX, road courses). Otherwise, if your car is just a fun runabout and you want it to have a bit more pep, I can understand the appeal of a pedal modification device.

Just be sure to turn the adjustment knob way down before you leave your next Cars & Coffee event. We don't need to be adding to the Mustang pedestrian body count.

Edit: I can't leave this alone without a tiny bit of trolling. My response to anyone complaining about pedal/throttle response in our cars:

 

[jonrjen]

jbird60,
Thank you for your response and presentation of the graph. It looks like the PedalMax will deliver along the lines of what I am expecting....FUN!!

While I don't drive fast or aggressively, I do, every once in a while like to "Goose" the Mustang a tad. After all, if it ain't fun to drive, it's just another car among many offered to the masses.

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