How This Little $249 Black Box Gave My 20 Year Old Volkswagen A Shot Of Adrenaline

For almost two decades I’ve watched as the people on car forums I frequent go straight from buying a new car to equipping them with a throttle controller. Back then, we called them pedal remappers. Regardless of what they were called, these devices promised quicker and sharper throttle response, like an ultra sport mode, but I just didn’t see it. I didn’t see why you couldn’t just push the pedal down a little harder and save $300 in the process.

My mind has been changed. The folks of Ultimate9 sent me their evcX throttle controller to test in a car of my choice. I was skeptical, but after using this device in my 2004 Volkswagen Phaeton for a few months I finally see why enthusiasts buy these things.

(Full Disclosure: PR for Ultimate9 reached out to us to see if we wanted to test a throttle controller. I doubted that these things worked, so I took on the test. Ultimate9 sent me a unit to test in my Phaeton. This is not a paid review.)

In my experience, the evcX unlocked attributes I never knew my 20-year-old executive car had. The device turned the oh-so-comfortable Phaeton into a sharp and responsive beast, but also gave the vehicle features it never had before like an Eco mode and a lockable throttle pedal. Yet, this device wasn’t entirely perfect. Let’s dig in.

How Throttle Controllers Work

Let’s start by explaining the device itself.

If you own a car with drive-by-wire throttle, you have probably noticed some level of delay in your throttle pedal. You hit the gas and it feels like it takes a third of a second or so for the command sent by the pedal to finally reach the vehicle’s Engine Control Unit (ECU) and execute the command. The signal actually reaches the ECU instantaneously, of course – the delay you feel is programmed in, and some cars have less delay than others. To use a personal example, my second-generation Smart Fortwos have a pedal delay that feels about a half-second long.

This delay contributes the feeling that a vehicle is sluggish to respond, regardless of the vehicle’s actual performance capability. In addition to controlling how much delay there is between pedal movement and throttle response, the ECU also affects the level of proportionality between pedal movement and throttle response. It’s only natural to assume that pressing the accelerator pedal halfway will command the ECU to deliver 50 percent of the engine’s available output. And the ECU may indeed be programmed so it feels like power is delivered linearly, with engine output increasing in direct proportion to pedal movement, when in reality the relationship between pedal movement and actual throttle application is likely a curve. Engineers spend a lot of time adjusting that curve to achieve the throttle feel the manufacturer determines is appropriate for the vehicke in question.

A throttle controller such as the evcX plugs in between the pedal and the ECU and allows you to alter that curve. Now, depending on the settings you choose, 10 percent of pedal input may output as 35 percent of throttle, thus making your car feel quicker off of the line. Or, you may set it so that 30 percent of pedal input results in 15 percent of throttle. The throttle controller may also remove the ramp-up function, resulting in a snap of the throttle when you hit the gas. Again, these systems are all about the feels and should make your old car feel more alive.

To be clear, none of this is making your car actually faster or more powerful. Nor does a throttle controller somehow make the signal from your pedal reach the ECU faster, or alter the engine’s tune. All a throttle controller does is manipulate the signals coming from your accelerator pedal. Your vehicle may complete a point-to-point run ever so slightly quicker, but that’s not extra power – it’s the delay being taken out of your vehicle’s throttle response.

In addition to making the engine feel more responsive, a throttle control can make your accelerator pedal more versatile. For example, a second-generation Smart Fortwo, like many cheap vehicles of that era, doesn’t have a Sport Mode, an Eco Mode, or any sort of selectable Drive Modes. A throttle controller can give an old car drive modes like a new car.

Or, maybe you have a nice car, but it still doesn’t have drive modes, like my Volkswagen Phaeton. Once again, a throttle controller adds a bit more modernity here. Throttle controllers may also help cars that do have drive modes. For example, the Kia Stinger is known for its programmed-in pedal “lag,” even in launch mode. A throttle controller can reduce that lag.

To repeat myself just so we’re clear here, a throttle controller is not going to add horsepower and will not make your car physically faster, but it can make the accelerator pedal feel more lively. For some people, that is worth the cost of admission.

The Ultimate9 evcX

So with all of that in mind, let’s get to what I tested.

Throttle controllers or pedal remappers are sold under perhaps a million brands. You’ve probably seen them under names like PedalCommander (by Banks — see gif below), Sprint Booster, Madness GOPedal, and countless generic units sold on a mind-boggling number of sites. All of these throttle controllers have the same basic function but may offer different features like app connectivity, Bluetooth, user customization, pedal lockers, and more. Of course, buying the cheapest throttle controller from a place like Alibaba may result in you getting a paperweight.

The throttle controller I tested is the Ultimate9 evcX. Ultimate9 was founded in 2015 by Australian 4×4 enthusiast Tim Tettamanti. He was on a mission to solve what he thought was one of the biggest problems with modern cars. As I said above, so many models are known for throttle lag regardless of how many ponies are under the hood. Tettamanti wanted to put an end to that. The company’s first product was the EVC iDrive and later, the company added the EVC and evcX product lines to its portfolio. Ultimate9 cut its teeth with Australian car enthusiasts but has since spread its wings around the world, including here in the United States.

As of writing, Ultimate9 sells OBD-II diagnostic monitors, battery monitors, heads-up displays, and flashlights, but the company’s core product remains the throttle controller.

Currently, Ultimate9 sells two different throttle controllers. There’s the standard EVC, which gives you an Eco mode, the sharp and sporty Ultimate mode, and an Adapt mode, a dynamic mode that sets a level of intervention based on how hard and fast you hit your accelerator pedal.

Then there’s the flagship evcX, which gives you the previous features but adds Bluetooth connectivity, an app, and a lot more modes to play with. We’ll get there in a moment.

I installed the evcX in my 2004 Volkswagen Phaeton V8. Installation is said to be plug-and-play. One end of the harness plugs into your accelerator pedal while the other end plugs into your factory harness. That’s it, right?

The reality of the installation procedure highly depends on your vehicle. In my case, I could not access the Phaeton’s accelerator pedal without breaking out my torx bits and pulling down a lower portion of the Phaeton’s dashboard. Once that was done, then the device was plug and play. My total installation time was about 30 minutes due to how convoluted the Phaeton’s dashboard was to work with.

From there, you have two choices. You can stick the evcX to a removable dashboard mount, or you can stick the evcX directly to the dashboard for a cleaner install. The Volkswagen Phaeton has a gorgeous interior, so I decided to go with the more permanent install. I stuck it to the parking brake release lever, threading the USB C cable through the dashboard to the throttle pedal. It looks nice and isn’t very intrusive.

Modes

I tested the Ultimate9 in each of its settings. I started with the Factory Mode, which is designed to replicate the vehicle’s stock configuration. True to the device’s word, I couldn’t tell the difference between the Phaeton in its actual stock configuration and the evcX’s Factory mode.

Next, I moved to Eco Mode, which is designed to smooth out throttle response. Now, the Volkswagen Phaeton already has a fine accelerator pedal. It’s one of the smoothest pedals I’ve ever used and that makes sense. I mean, it’s basically a Bentley with a Volkswagen badge, so coddling occupants in the lap of luxury is the goal. Well, the evcX’s Eco mode makes the pedal and throttle response even finer.

Despite the naming, Ultimate9 says Eco Mode is great for when you really need to have fine control of your throttle, such as when you’re trying to get through loose, uneven terrain. If you go off-roading, you know how accidentally stabbing your throttle can get you stuck, so Eco mode tries to prevent you from burying the throttle. For a road vehicle like the Phaeton, Eco mode makes the car even gentler than normal and makes the car feel slower, so much that someone sleeping in your vehicle won’t even wake up in heavy traffic.

Ultimate9 says Eco mode is also great for if you need to do low-speed maneuvers while towing a trailer. Again, the whole idea here is to dull pedal response to make slow driving easier. Eco mode also comes with 9 levels of sensitivity, which makes it range from making your car feel like it’s working in slow motion, to more or less the Eco mode you get with a new car.

Next, I tried the Lock Mode. This one is pretty self-explanatory: It disables your throttle pedal entirely. You can then disconnect the screen and take it with you, making the car harder to steal since the pedal isn’t going to work at all. I can confirm that it works!

Next up is Valet Mode, which is designed to stop valets from taking joyrides in your car. Throttle response is dulled below factory settings and the evcX imposes a 50 percent maximum RPM limit. In my experience, that’s just enough to make sure your car can still obey the speed limit while someone is parking your car, but makes it un-fun to drive and thus, hopefully not attractive for a joyride.

From there, I tried out the Anti-Slip Mode, and that required me to wait for some rain. Now, the Phaeton uses Torsen-based 4Motion AWD, so this sedan is already exceptionally capable when things get slippery. Using the Anti-Slip Mode dulls throttle response and there are nine sensitivity settings to choose from depending on the slipperiness of the conditions at hand. The whole idea is to help prevent loss of traction in rain, snow, ice, or mud that might otherwise occur if you apply the throttle with anything less than the utmost smoothness and precision.

This Anti-Slip mode feels just like the Rain-driving mode in any modern car. As I noted before, my Phaeton doesn’t have any driving modes, so having a more or less Rain Mode is pretty cool, even if I rarely drive the vehicle in the wet, anyway.

From here, the system has three modes remaining. I spent most of my time in the Adapt Mode, which is supposed to give you a dynamic throttle response based on how hard and fast you’re hitting the pedal. Honestly, most of the time it was hard to tell if Adapt was doing anything at all. I did notice it sometimes, but most of the time my Phaeton drove largely as normal. It’s possible here that Adapt works well enough that the changes are not really felt unless you’re looking for them.

Most people will be buying this throttle controller for the Ultimate mode. This is the mode that really cuts out the throttle lag and cranks up the intensity of your pedal inputs. Once again, there are nine levels of sensitivity here. Ultimate mode on level 1 gives my Phaeton a snappy initial tip-in but otherwise feels like stock.

On the far other end is the Ultimate9 mode, which gives the throttle pedal an immediate snap, followed immediately by a response like you just welded the pedal to the floor. If you’re driving a two-wheel-drive car, you might even get the tires to chirp because you’re going from no throttle to full throttle in just a snap. In the case of the Phaeton, my head got kicked back into the headrest and I got to watch the RPM needle race toward redline.

Again, this isn’t making the car faster, just taking out all of the factory delays. Driving the Phaeton in Ultimate9 was actually pretty weird. The Phaeton is supposed to be this easy, smooth, and gentle ride, but Ultimate9 mode was making the car try to cosplay a sports car. It was equal parts hilarious and fun because the Phaeton clearly wasn’t designed to launch off of the line quickly.

Using the Ultimate mode and its nine levels of sensitivity made the Phaeton feel more sporty in most situations. If I hit the pedal to pass, the car quickly downshifted and built speed in what felt like faster than stock. It felt similar when punching the throttle on hills and when passing slow tractors on country roads. Driving around in Ultimate mode made me realize that Volkswagen baked in a lot of lag to make the Phaeton luxurious. Now, the Phaeton had its own Sport mode.

Finally, we arrive at the last mode, which Ultimate9 calls the Launch mode. Ultimate9 says that Launch mode is based on the aforementioned Ultimate9 mode, but is optimized to reduce wheelspin. I have no idea how this is supposed to work in practice because again, my Phaeton is a full-time AWD vehicle. Launch mode felt exactly like Ultimate9 mode and if there is a real difference I did not feel it.

Limitations

Here’s where we arrive at where the Ultimate9 evcX shows some cracks.

A lot of the people who will be buying throttle controllers will have older cars and you may need to consider your vehicle’s quirks and condition. If you’re like me, your car never had drive modes and it was never designed with something like a throttle controller in mind. Your car may not be designed to account for having a massively more aggressive pedal response. This can have some unintended consequences.

For example, my Phaeton has about 255,000 miles on its odometer. Prior to installing the evcX, I made sure to drive the vehicle hard through all gears to make sure things were still good. They were. In most modes, the vehicle shifted as designed.

However, the vehicle did not always react well to Ultimate9 mode. Sometimes, and this was only in Ultimate9 mode, the engine’s RPM would shoot up near redline during gear changes. In every other mode and at lower Ultimate sensitivities, the vehicle would change gear as it should and not flare. Unfortunately, huge RPM flares during shifts can damage a VW’s transmission, so I let off of the gas between each shift in Ultimate9 mode as a precaution.

I’m not sure if this is a weird artifact of the throttle controller’s impact on the accelerator pedal or just the fact that I’m driving a high-mileage VW, but it’s worth noting. Again, it didn’t happen with lower sensitivities and in the other modes, but when the controller was set to 9, it seemed the transmission seemingly didn’t always know how to handle things. Also, this didn’t happen when doing full-throttle runs with the evcX disconnected. I think this part is important because not everyone buying a throttle controller is going to be driving a brand-new car.

The other problem I have is with compatibility. As many of our readers know, I own 15 cars, many of which are compatible with the evcX. All of my Volkswagens can use the evcX. However, I cannot easily buy the harnesses that would connect the evcX to my other Volkswagens. Instead, Ultimate9 wants you to buy an entire different evcX unit for that other car. The evcX costs $249 per unit. That gets expensive quickly if you want to use it in more than one car.

So, I would suggest that a future version of the Ultimate9 throttle controller have some sort of quick swap capability. The device already quickly disconnects from the USB cable, so just take that a step further!

Resident former auto engineer David Tracy is curious about how these devices somehow pass the legal sniff test. The companies that market these devices say they’re legal in all states, but David notes that the EPA isn’t fond of anything that might change fuel economy and emissions. I didn’t see a notable change in fuel economy during my testing.

Changed My Mind

Throughout all of this, I was shocked that I’ve been wrong for nearly two decades. I’ve long thought of pedal remappers and throttle controllers as snake oil.

However, as the Ultimate9 evcX has shown, they can be very real. My Volkswagen Phaeton now has a ton of driving modes and they’re far more customizable with those sensitivity settings than a new car. I can set the evcX to Eco mode for a gentle cruise or put it into Ultimate9 when I want to giggle between stoplights. True to the company’s advertising, the throttle controller also kicked the throttle lag right out of the door.

So, the big question then becomes if these changes are worth $249. I think it depends on the vehicle and what you’re looking to get out of it. While it’s super awesome that my Phaeton now has a Sport mode of sorts, I still largely drive the car as the luxury vehicle it was built as. So I probably wouldn’t spend that much on a throttle controller for a Phaeton. With that said, something like this does sound like it’ll make my Volkswagen Jetta SportWagen TDI a lot more responsive.

In other words, your mileage may vary. If your vehicle has horrible throttle lag, this might be $249 worth spending. If your car already has a snappy throttle and all kinds of driving modes, maybe spend your money on some other mod. One thing I can tell you is that at least with these name-brand controllers, they’re not just blowing smoke.