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I have a amg GTS and I notice when I put my foot down I get a solid 1 second delay before the car starts to pull hard. It’s especially evident from a standstill so I’m trying to understand why that is. I imagine it’s lag from the turbos trying to build boost? The only way I can avoid the delay is easing into the acceleration but that takes away the wonderful “oh ****” feeling when you plant your foot. Perhaps it’s the ECU cutting traction? Limiting the traction (sport) mode helps a bit but there’s still a delay.
I have a amg GTS and I notice when I put my foot down I get a solid 1 second delay before the car starts to pull hard. It’s especially evident from a standstill so I’m trying to understand why that is. I imagine it’s lag from the turbos trying to build boost? The only way I can avoid the delay is easing into the acceleration but that takes away the wonderful “oh ****” feeling when you plant your foot. Perhaps it’s the ECU cutting traction? Limiting the traction (sport) mode helps a bit but there’s still a delay.
NOPE. You need to get the car diagnosed and possibly tuned at the MB dealer.
NOPE. You need to get the car diagnosed and possibly tuned at the MB dealer.
Jerry
why do you say that? Should the throttle response be instantaneous? I thought most turbo cars have slight lag. I will say however in race mode I don’t feel much lag at all.
Well, pretty much all turbocharged engines have some turbo lag, unless they have an electric turbo or a hybrid system that can do torque fill. Having said that, though, the AMG V8 feels as close to a naturally aspirated engine that you can get with a turbocharged engine. It's a very responsive engine and turbo lag is virtually non-existent. What mode are you in? The throttle map in Comfort is deliberately feathered, but in S+ and Race this engine just responds and goes, and Race mode has a very linear throttle response that if I didn't know it had turbochargers I could swear it was a naturally aspirated engine. AMGs stated goal with this engine was to make it feel and respond like a naturally aspirated engine. Traction control/ESP can and does limit the engine torque w/o necessarily any indication in the instrument cluster. With my 2019 C63S coupe in Comfort mode it definitely limits torque if I step on the throttle while turning. It does this proactively to avoid a spinout, but with ESP in Sport and AMG DYNAMICS in Pro or Master it doesn't do that and just goes and slides around the turn. Your GTS doesn't have the new AMG DYNAMICS system, nor the 9 stage traction control system that the GT R and above have as well as the 2019+ C63S, so the only way you can make ESP less intrusive is by putting it in Sport Handling mode or turn it off completely.
Last edited by superswiss; 06-11-2022 at 05:38 PM.
Well, pretty much all turbocharged engines have some turbo lag, unless they have an electric turbo or a hybrid system that can do torque fill. Having said that, though, the AMG V8 feels as close to a naturally aspirated engine that you can get with a turbocharged engine. It's a very responsive engine and turbo lag is virtually non-existent. What mode are you in? The throttle map in Comfort is deliberately feathered, but in S+ and Race this engine just responds and goes, and Race mode has a very linear throttle response that if I didn't know it had turbochargers I could swear it was a naturally aspirated engine. AMGs stated goal with this engine was to make it feel and respond like a naturally aspirated engine. Traction control/ESP can and does limit the engine torque w/o necessarily any indication in the instrument cluster. With my 2019 C63S coupe in Comfort mode it definitely limits torque if I step on the throttle while turning. It does this proactively to avoid a spinout, but with ESP in Sport and AMG DYNAMICS in Pro or Master it doesn't do that and just goes and slides around the turn. Your GTS doesn't have the new AMG DYNAMICS system, nor the 9 stage traction control system that the GT R and above have as well as the 2019+ C63S, so the only way you can make ESP less intrusive is by putting it in Sport Handling mode or turn it off completely.
Yup I try it in all settings and in comfort mode there’s definitely a delay and in sport, sport + it’s less and less. In race mode it feels non existent but I tend not to use race mode on the street as you run out of run very quickly. For example when I’m on the highway and I put my foot down there’s a slight delay like the car thinks for a second and then goes…but, it almost feels normal for what I’m asking the car to do. I was just curious if there was a slight lag when accelerating or if it was normal
Yup I try it in all settings and in comfort mode there’s definitely a delay and in sport, sport + it’s less and less. In race mode it feels non existent but I tend not to use race mode on the street as you run out of run very quickly. For example when I’m on the highway and I put my foot down there’s a slight delay like the car thinks for a second and then goes…but, it almost feels normal for what I’m asking the car to do. I was just curious if there was a slight lag when accelerating or if it was normal
Ok, I think what you feel is actually the transmission delay. The GT has a dual clutch transmission, and the problem with dual clutch transmissions is that they only shift fast if they can shift sequentially and the next gear has already been preselected. If you just stump it on the highway, though, it has to downshift multiple gears to give you the desired acceleration. This is a slow shift with a DCT and is referred to as gear hunting. It's particularly slow if the next gear is on the same shaft as the current gear. For example you are cruising along in 7th and then it wants to downshift to 5th or 3rd, which are both on the same shaft. In this case you get a very slow downshift as it first has to declutch, then change the shift forks and synchronize the gears for the required ratio and then engaged the clutch again. During this time you get an interruption of tractive force and a very noticeable delay.
This issue doesn't exist with the MCT transmission in other AMGs like my C63S. The MCT, because it uses a planetary gearbox and multiple clutches, it can skip gears in an instant. A downshift from 9th gear to 4th for example on the highway with kickdown happens in an instant. There's pretty much zero delay and zero interruption in tractive force. This particular situation is really the Achilles heel of a DCT. DCTs are great on the track when shifting sequentially, or if you are primarily shifting manually and select the proper gear in advance before stepping on the throttle, but they fall flat on their face if they end up having to shift out of sequence.
Last edited by superswiss; 06-11-2022 at 06:21 PM.
I'm with the others, this car really has no lag to me. But I have nearly lost my car due to the delay type thing you are talking about but that to me was just where I was in the wrong gear and the car is too powerful. I'm more careful now if I'm slogging around in C and decide to take off, instead of waiting on the car, I'll manually downshift a gear or two.
The other funny thing to me is the bump you get as the transmission downshifts coming to stops. I have another car that does that, but no where near as noticeably. Actually I enjoy it, but it is pretty wild.
Yeah, I can really only encourage folks to drive more in manual mode. Personally, I drive in manual mode at least 90% of the time. I have my Individual mode configured to put the transmission in M. Particularly on the highway, unless I'm just cruising along with DISTRONIC, I'm permanently in manual mode and control the gears myself. After 20+ years of driving manual transmissions, making sure I'm always in the right gear is second nature. As good as the automatic modes are, they still can't read your mind. These cars are simply more fun in manual mode, and if you know what you are doing, you get the response you want.
Last edited by superswiss; 06-11-2022 at 08:47 PM.
Yeah, I can really only encourage folks to drive more in manual mode. Personally, I drive in manual mode at least 90% of the time. I have my Individual mode configured to put the transmission in M. Particularly on the highway, unless I'm just cruising along with DISTRONIC, I'm permanently in manual mode and control the gears myself. After 20+ years of driving manual transmissions, making sure I'm always in the right gear is second nature. As good as the automatic modes are, they still can't read your mind. These cars are simply more fun in manual mode, and if you know what you are doing, you get the response you want.
Ah, thanks for the insight here. I’m gonna start driving it more in manual mode. It sounds like keeping it in manual mode would help avoid acceleration lag. Any tips for using the paddle shifters on the AMG?
Ah, thanks for the insight here. I’m gonna start driving it more in manual mode. It sounds like keeping it in manual mode would help avoid acceleration lag. Any tips for using the paddle shifters on the AMG?
A couple of tricks that come in handy:
If you press and hold the downshift paddle for a second or so it drops to the lowest possible gear. Basically a manual kickdown.
You can press the downshift paddle multiple times in quick succession to drop multiple gears in one shot. For example pull it twice quickly and it downshifts 2 gears in one blip.
Last edited by superswiss; 06-11-2022 at 11:37 PM.
If you press and hold the downshift paddle for a second or so it drops to the lowest possible gear. Basically a manual kickdown.
You can press the downshift paddle multiple times in quick succession to drop multiple gears in one shot. For example pull it twice quickly and it downshifts 2 gears in one blip.
Ahh that’s awesome! Thanks for the tips! Silly question, do you notice the throttle is ‘heavier’ in manual mode? When I played with it before I almost felt like I need to push the accelerator slightly down more to start moving the car
Ahh that’s awesome! Thanks for the tips! Silly question, do you notice the throttle is ‘heavier’ in manual mode? When I played with it before I almost felt like I need to push the accelerator slightly down more to start moving the car
Nope, never felt anything like that. It's a drive-by-wire system and the throttle pedal always feels the same. It just has a different map based on the Drive mode you are in. In Comfort the map is progressive, in S and S+ it's aggressive and in Race it's linear. So a given amount of pedal travel results in a different response depending on the mode, but it doesn't change any weighting in the physical pedal travel.
I have a amg GTS and I notice when I put my foot down I get a solid 1 second delay before the car starts to pull hard. It’s especially evident from a standstill so I’m trying to understand why that is. I imagine it’s lag from the turbos trying to build boost? The only way I can avoid the delay is easing into the acceleration but that takes away the wonderful “oh ****” feeling when you plant your foot. Perhaps it’s the ECU cutting traction? Limiting the traction (sport) mode helps a bit but there’s still a delay.
I've never felt anything like this in my car, it was always near instant power/acceleration.
Nope, never felt anything like that. It's a drive-by-wire system and the throttle pedal always feels the same. It just has a different map based on the Drive mode you are in. In Comfort the map is progressive, in S and S+ it's aggressive and in Race it's linear. So a given amount of pedal travel results in a different response depending on the mode, but it doesn't change any weighting in the physical pedal travel.
Agree with Superswiss including the drive selections. I think I've only had my car in comfort mode twice since I've owned it and I am always in manual mode, but for other reasons too. I don't like the factory throttle maps as they are all geared towards fuel economy, even in the sports modes. For example, if I let the car shift itself and I am leaving a typical traffic light, I'll be in 5th gear in several hundred feet. This type of throttle map contributes to carbon buildups on the backs of the intake valves on direct inject engines. I always wind out shifts to at least 3K or 4K RPMs.
On the "Drive by Wire" and throttle maps, this is a complex subject and can be difficult to understand. MFGRS use different throttle maps to complement different selectable "mode" settings as illustrated in SS' diagram above. I can illustrate it a little further using a scan I did on a recent tune doing a third gear pull.
On the left, you can see 4 different rows of "throttle" (3 throttle and 1 accelerator)
COMMANDED throttle - comes from the driver. In this case I was commanding 100% throttle.
RELATIVE throttle - is what I got 71%, at the moment of the white vertical line when I commanded 100%, and what the fueling and timing was responding to
THROTTLE POSITION or better known as "actual" or "physical" throttle position (based on what the TPS sees) 83.9%
The ECU was using a Position D map
As I select different driving modes, and based on what (how) I COMMAND throttle, the combinations/patterns of these 4 throttle positions change based on the architecture built into the EMS.
I'm guessing here, but I think what Poutab1 was referring to about a "heavier" throttle feel when he stated
Silly question, do you notice the throttle is ‘heavier’ in manual mode? When I played with it before I almost felt like I need to push the accelerator slightly down more to start moving the car
sounds more like the DCT clutches engaging to get the car rolling from a standstill. Sometimes that can feel like more pedal is being pushed to actually get the car rolling and is really happening.
18 AMG GTC and 22 F150 Limited. Past owner 16 Maybach, 17 Brabus Smartcar, 06 Ford E150, and 22 G70
If I have the GTC in comfort mode there is a small amount of lag but it is probably a combination of computer telling car to be in highest gear possible (and then having to downshift when I give gas) and turbo lag because engine is in really high gear and turning very low rpm.
Now if I put car in any other mode especially s+ or race mode then there is no turbo lag because computer keeps trans is gears that leave the engine turning high rpms.
Agree with Superswiss including the drive selections. I think I've only had my car in comfort mode twice since I've owned it and I am always in manual mode, but for other reasons too. I don't like the factory throttle maps as they are all geared towards fuel economy, even in the sports modes. For example, if I let the car shift itself and I am leaving a typical traffic light, I'll be in 5th gear in several hundred feet. This type of throttle map contributes to carbon buildups on the backs of the intake valves on direct inject engines. I always wind out shifts to at least 3K or 4K RPMs.
On the "Drive by Wire" and throttle maps, this is a complex subject and can be difficult to understand. MFGRS use different throttle maps to complement different selectable "mode" settings as illustrated in SS' diagram above. I can illustrate it a little further using a scan I did on a recent tune doing a third gear pull.
On the left, you can see 4 different rows of "throttle" (3 throttle and 1 accelerator)
COMMANDED throttle - comes from the driver. In this case I was commanding 100% throttle.
RELATIVE throttle - is what I got 71%, at the moment of the white vertical line when I commanded 100%, and what the fueling and timing was responding to
THROTTLE POSITION or better known as "actual" or "physical" throttle position (based on what the TPS sees) 83.9%
The ECU was using a Position D map
As I select different driving modes, and based on what (how) I COMMAND throttle, the combinations/patterns of these 4 throttle positions change based on the architecture built into the EMS.
I'm guessing here, but I think what Poutab1 was referring to about a "heavier" throttle feel when he stated
Silly question, do you notice the throttle is ‘heavier’ in manual mode? When I played with it before I almost felt like I need to push the accelerator slightly down more to start moving the car
sounds more like the DCT clutches engaging to get the car rolling from a standstill. Sometimes that can feel like more pedal is being pushed to actually get the car rolling and is really happening.
Very interesting. Thanks for sharing the details here. Looks like the biggest takeaway for me is to get the most fun and responsiveness out of the car, keep it in manual mode!
WRT throttle mapping/response, there are 2 things to consider:
- the mapping for the pedal position
- the mapping the ECU does in response to your "pedal-based request" ... which can be _very_ different from what you've requested via the pedal as the ECU takes into account such things as traction-control and (if you have it) the dynamics mode
Many of these videos show the throttle pedal position as well as the ECU throttle information for both a GTR (which has dynamics) and an older C63 (without dynamics). It's quite instructive if you want to see how these work under various conditions: https://www.youtube.com/playlist?lis...XDlOogyMcpvvbW
why do you say that? Should the throttle response be instantaneous? I thought most turbo cars have slight lag. I will say however in race mode I don’t feel much lag at all.
There is no discernible lag. You do need to ensure the transmission is in the right gear though. If you're in 4th in Comfort doing ~20mph, then yeah, it will take a second or so to downshift.
06-11-2022, 04:11 PM
