I've had my 2020 coupe for 1k miles. I don't do a lot of highway driving and always felt like the C43 was uninspiring on city and neighborhood streets. Different story on the highway but like I said, I spend most of time in the city.
​​​​​​I came from an ECU tuned BMW 328i that felt much more at home in my typical driving conditions. I would throw it into sport+ and always had instant torque as soon as I touched the pedal. My C43 always felt sluggish unless I was really getting into it, even in sport+ mode.

Yesterday I installed a throttle controller (Pedal Commander w/ BT) and what a difference. I always thought the C43 motor lacked torque or had serious turbo lag, but it's just *****ty Throttle mapping from the factory. To anyone who spends a majority of the time city driving, I'd highly recommend trying one out.

Also, get a unit with Bluetooth connectivity. The controllers are a little cheesy looking and do not belong in a Mercedes interior. Mount the controller somewhere accessible but out of site and make adjustments with your phone when necessary.

 

I actually got the Sprintbooster for the same reason as you. It really helps to get rid of that unresponsive/dead pedal feel. I like the Sprintbooster since it's tiny and once I found the setting that I like, I just disconnect the controller and it maintains that setting for good. I did not find the need to keep changing different throttle mapping with the controller, since that's what I use the car's drive mode for anyhow. The car definitely feels so much better now.

 

Second that.

 

Third .

 

My C450 does the same thing! I’ve almost been killed driving it in the city because going from drive/reverse and vice versa makes a serious lag that lasts a long 3 seconds before the power kicks back in. I’m gonna buy one of these for sure.

 

I doubt that an external throttle-mapping device is actually needed. If you put a (for sure, pre-facelift and likely facelift) C43 into sport mode, the throttle response is _very_ sharp, especially with low throttle-pedal percentages (and feels like 80% of pedal gets you full throttle).

For on-street driving in both our C43 and C63 S, I use an individual setting with comfort suspension and sport drivetrain (which also turns off eco/start-stop mode and uses first gear from stops). When switching between C43 and C63 S, I'm constantly surprised at how "touchy" the start-of-pedal response is on the C43, compared to the C63 S.

I've always figured that this rapid, low-pedal response is one of the reasons people complain about "bucking" in low gears on the C43 ... i.e., because you have to be _very_ precise with the throttle when in sport/sport+ mode. Given that a C63 "always wants to kill you" anyway, it's a good thing that its throttle is not as "touchy" as the C43's on the low end (in sport/sport+)! #;-)

 

The drive modes do not do enough to address the issue. I've tried. Say for instance the pedal is dead from 0-10% throttle input. Putting the car into Sport+ settings will still give you that dead pedal from 0%-10% throttle input. The only thing Sport+ does is making it so that 10% to 70% throttle input feels like 10% to 100%...so effectively the last 30% of throttle input doesn't yield much, but more importantly it still did not fix the dead 0-10% portion. The car just feels sensitive from 10% throttle input onward.

Throttle mapping devices seem to shift the entire throttle map curve over. So instead of 0%-10% dead then 10% to 100%, it shifts it to 0%-2% dead, then 2% to 70% with 70% throttle input opening the throttle body completely 100%.

Watch this video at 39 seconds, you'll see that this device actually causes the throttle body itself to open more instantaneously while still allowing you to feather the throttle if you so desire so it doesn't feel overly sensitive and jerky:

 

wow that video really opened my eyes to the throttle response. So our cars included, there's that much delay and slowness of opening the throttle body?

 

I'm sure every car is different and this video is probably showing the worse example of throttle body lag just to promote the Sprintbooster product, but nonetheless it does show what this device can do and I can confirm first hand that the throttle in my C43 feels much more responsive after installing the Sprintbooster. I also do not have it set all the way up either since that's too sensitive for me.

 

Does the throttle wear quicker or any issues with the stock tune mapping? That visual is pretty amazing, and would be nice to get a mechanical feel to the throttle more.
I'm pretty happy with the S+ right now, so I'm on the fence with this one still..

 

I don't have proof but I doubt this wears the throttle body quicker than normal. The only thing I've notice is less pedal and more sensitivity. If nothing about the stock throttle response is bothering you, then I would say don't worry about it. I only bought this because I'm sensitive and the delay in response annoyed me. It's not a cheap product though, and it does not add power to the car.

 

Coming from strictly manual cars, I have always treated the c43 the same as I did with a manual car. There will always be a lag in power if you are a high gear at a low speed. Even in Sport + the c43 will put you in a gear a few ahead of where you may want to be. When you really mash the pedal the auto tranny will switch to the lowest gear, but there is obviously a lag. The holding down of the left shift paddle will allow you to do this “manually.” Otherwise, be aware of the gear you are in if you are feeling like spirited driving. I think these “pedal tuners” are a waste of money.

 

"Obviously" that's your opinion and if you constantly want to be aware of what gear your in, that's your perogotive. Being that it's a 9 speed auto that likes to be in 6th gear at 35mph, it's a stretch to "treat it like a manual transmission". The whole point of this thread is that I'm comparing it other auto transmissions in the same market space that perform significantly better from the factory, and that a throttle tuner helps close this gap. I have a feeling if you actually tried one, your opinion may change.

 

I love having a slow pedal though...

Feels more linear rather than an on-off switch. I want to be able to drive like a grandpa when I want to but know that I can press harder for more power without kick down.

Sport mode is necessary for that though. Comfort and eco may be a bit slow for quick response.

 

This is actually not the problem that these throttle controllers are trying to solve. Of course, if you are in 7th gear at 1700 rpm and mash on the throttle, it's not going to go anywhere, but this is purely due to the car not giving you power...NOT because of throttle input. What I'm talking about is say you're in 2nd gear at 4,000 rpm and you depress the pedal 10% of the way, you don't even notice the car getting much power until you depress the pedal a little further. The throttle controller helps in this scenario so that in 2nd gear at 4,000 rpm, depressing the pedal just 5% actually opens up the throttle body QUICKER and WIDER so that you're actually experiencing some sort of feedback.

 

Unless your car is materially different than mine, there is absolutely no lag in acceleration if in the right gear. If I am in second gear at 4K and hit the the throttle at all, instant acceleration in line with the desire of my right foot (be it 10% or 100%). I have never once thought that the pedal needed to be more responsive in a scenario such as that you presented.

 

I agree with you on this. If I manually downshift to get the car within it's powerband, the throttle response feels pretty good. However, if you are just cruising along and happen to be in 6th gear at 2k rpm, the throttle response is basically non existent unless you mash the pedal. With the pedal tuner, the car seems to respond with much more torque in the same situation and gets you into the power much sooner. The throttle does in fact open sooner and the added responsiveness is noticeable.

 

I'm with @C43HeartBoost on this one. What you are experiencing is largely a gearing issue. 10% throttle input in a high gear and low rpm isn't gonna do much. That doesn't nominally increase wheel torque enough to accelerate you in any meaningful way. Unfortunately, you'll have to give it some more throttle to persuade it to downshift if you insist on tooling around in D. The alternative is to give the downshift paddle two quick pulls in rapid succession while on the throttle to instantly downshift 2 gears and you will start moving. For example with my C63 I pretty much stay in M on the highway and cruise along in 9th gear and when I need to pass somebody or need to get over to make my exit or something I simultaneously get on the throttle moderately and do the aforementioned 2 gear instant downshift and off I go w/o any need of stabbing the throttle and overreact with a kickdown. It is largely why I keep it in M on the highway, I don't like how automatic transmissions quickly resort to kickdown and then the car responds with way more acceleration and power than I really wanted. As good as automatic transmissions are nowadays, they still can't read my mind. I also think these throttle controllers solve a problem that is only a problem in some people's mind, and I get the impression it's largely a problem for those who haven't driven manual transmission cars most of their lives. Anticipating the right gear for an upcoming maneuver or manually downshift in advance is just kinda second nature.

 

What about when you’re at a stop and you’re already in first gear? What about the lag then? or the lag when you’re backing up and then need to go to drive in a hurry and there’s no power? And every car has it. I know this because a friend of mine works for Mercedes Benz.
These cars need the pedal response fixed in them all the way around unless you’re one of those people that are never in a hurry. That video at the top of this thread proves it. I can’t wait for mine to get here. It’s the one of few things I hate about my C450.

 

Its a different mentality for sure. I learned to drive in a manual car and had manuals until I lived in a major city with a lot of stop and go traffic, and that's where I think a throttle controller really shines. I'm not here to convince any one as it is merely a preference, but saying it's a waste of money because people don't understand how gearing works is annoying at best. Don't knock it till you try it is all I'm saying. At a minimum, hop on YouTube and watch some unbiased reviews on throttle controllers from anything to C63s, McLarens, and even diesel trucks. There are videos where throttle controllers make the car "quicker" from 0-60 in identical conditions based in the fact they convince the throttle to open sooner. I was skeptical too until I actually tried one.

 

I was in the same camp 10 years ago ... until I've tried it. Have it installed in almost all (quite a few) MBs I had ever since.

 

At least with my C63 I don't have lags that you describe. From a stop the car moves in accordance to how much throttle I give it. The only slight lag is turbo lag obviously, but at least in the C63 a 4 liter V8 has plenty of torque to move from a stop. The throttle responds instantly. Sometimes actually I even have to let off again if I have a slow poke ahead of me, who is taking off like a grandma. Also not sure about the lag when backing up and then going forward. There's some inherent delay in the transmission as it needs to change gears and it protects itself if you don't come to a full stop before changing direction, so if you get on the throttle before the transmission has actually engaged the forward gear, then yes there is a lag, but once the gear is in, all the power is there. Are you perhaps running into Drive Away Assist which temporarily limits the vehicle's speed to 1 mph if a critical situation is detected. I definitely have that occasionally if I'm close to an obstacle, but you can tell by the LIM symbol on the camera image.

That video above is purely a sales pitch for sprint booster and how supposedly all the knockoffs are inferior. OP apparently bought one of those inferior knockoffs. He spends like half the video ripping the knockoff like that sprint booster is somehow a work of art. I would certainly not want this anywhere visible in my car. It also proves nothing. That throttle contraption is what? What car is this supposedly from? It's obviously made for effects. Yes, there are delays in the throttle opening. They are by design and that's the whole point of the throttle maps, and the different drive modes that we have in these cars affect how fast and how direct the throttle opens. It's more delayed in comfort to make the car more comfortable to drive at low speeds and it's faster more direct in S+ and Race in case of the C63S. I can see how these throttle controllers can be useful in cars that only have one throttle map, but honestly they only solve a problem if you believe there is one.

Here in case you are not aware of the Drive Away Assist.

 

The issue to me isn't the delayed response in Comfort. It's the fact that the first 10% of pedal travel doesn't do much, and then all of a sudden the power comes rushing in, causing the car to lunge. The problem for me was dead pedal for the first couple inches of travel AND ALSO the lack of linearity. I can only speak for the Sprintbooster, since that's what I have, and it seems to help me better control my car's throttle as well as "feeling" like the car is faster because a bit of input opens up the throttle body a lot more.

The video does look like a sales pitch. As I mentioned when I posted the video, just take that with a grain of salt. However, if the product is doing what is actually shown there, then that would help a lot. Nonetheless, end of the day, if your driving experience is improved with a throttle controller then that's the deciding factor. We can go back and forth about the legitimacy of what these throttle controllers do, but a lot of people, including myself now, have tried it and it does "feel" like it's doing what it's suppose to do. Even if all it's actually doing is increasing sensitivity, it really does make acceleration feel a lot better. I guess you end up with a "short throttle" depending on how high you set these things, but it feels good to depress 10% and feel 30% throttle response.

I don't think it's valid to say that a product doesn't work if you have not tried it yourself yet though. It is a bit strange to me to not have heard of anyone trying these products and then saying that they don't like it. I have heard of issues such as throwing CEL and such, but nothing in regards to the performance of the product.

 

Agreed, like a placebo, if it makes you feel better that's all it counts. It's not so much that I question the legitimacy of it or dispute that it does something, but to that throttle response point, many, including myself, believe the throttle should be largely linear. 10% throttle input should result in 10% power output. It gives you more and finer control over the engine. Turbo charged engines already mess with this formula where the power delivery is often non-linear once the boost kicks in. AMG does a good job at least with the V8TT to make it more or less feel like a naturally aspirated engine. Ferrari also does torque management in their turbo V8 for the same reason, so you don't get this hockey stick response or non-linear throttle response.

 

What you are describing sounds great, but with the C43 it's just not my experience. The power delivery is not linear and often feels like a SEVERE hesitation. Unless you're manually shifting and into the powerband, the first inch of the pedal feels like a dead zone.

To add, my buddy has an early 2000's E55 AMG which is a N/A V8. His sprintbooster drastically changes the aggressiveness of the car - Absolutely no placebo there. He basically uses it as a make shift drive select for when he wants to get sideways.