Speedshift - Mercedes Benz SLK Forum

AMGs For those high performance Mercedes-Benz R170-SLK 32/R171-SLK 55/R172-SLK 55 cars tuned by AMG -

 1Likes
  • 1 Post By Deafy
 
LinkBack Thread Tools
#1 Old 10-24-2013
Banned
 
Deafy's Avatar
 
Join Date: Jul 2013
Posts: 992
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 26
Thanked 100 Times in 95 Posts
(Thread Starter)
Speedshift

Before the 'MCT' was introduced, what's the difference between the 7G transmission with 'AMG Speedshift' and all the other 7G units fitted to 171s?

Wikigoogle couldn't really satisfy my curiosity.
Deafy is offline  
Sponsored Links
Advertisement
 
#2 Old 10-28-2013
Banned
 
Deafy's Avatar
 
Join Date: Jul 2013
Posts: 992
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 26
Thanked 100 Times in 95 Posts
(Thread Starter)
Tough question eh guys?
Deafy is offline  
#3 Old 10-28-2013
Administrator/Founding Member

 
jbanks15's Avatar
 
Join Date: Jun 2006
Location: Tampa, Florida
Vehicle: 2009 SLK 55 AMG Kleemann Supercharger, ECU tune, Headers and LSD, CF Diffuser
Posts: 91,239
Country:
Chats: 38
Mentioned: 459 Post(s)
Tagged: 5 Thread(s)
Quoted: 6498 Post(s)
Thanks: 3,232
Thanked 11,035 Times in 8,392 Posts
wiki didn't satisfy?

AMG SpeedShift MCT[edit]

Mercedes-AMG developed the 7-speed MCT "Multi Clutch Technology" planetary semi-automatic transmission.
The MCT transmission is essentially the 7G-Tronic automatic transmission without a torque converter. Instead of a torque converter, it uses a compact wet startup clutch to launch the car from a stop, and also supports computer-controlled double declutching. The MCT (Multi-Clutch Technology) acronym refers to a planetary (automatic) transmission’s multiple clutches and bands for each gear.[4]
The MCT is fitted with four drive modes: “C” (Comfort), “S” (Sport), “S+” (Sport plus) and “M” (Manual) and boasts 100 millisecond shifts in "M" and "S+" modes. MCT-equipped cars are also fitted with the new AMG DRIVE UNIT with innovative Race Start function. The AMG DRIVE UNIT is the central control unit for the AMG SPEEDSHIFT MCT 7-speed sports transmission and all driving dynamics functions. The driver can change gears either using the selector lever, or by nudging the steering-wheel shift paddles. The new Race start Function is a launch control system which enables the driver to call on maximum acceleration, while ensuring optimum traction of the driven wheels.

Maybe you need new Burger King's Satisfries!



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Jeff, US Army Master Sergeant Retired
Administrator/Founding Member
2009 SLK 55 AMG Black/Black
Kleemann Supercharger thread here:

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Kleemann ECU Tune, headers and downpipes thread here:

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Albums:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

ClearBra
OEM MB Plexiglass Draught Stop
Smarttop version 3.22
Previous - 02 SLK 320, 05 SLK 350
jbanks15 is online now  
 
#4 Old 10-28-2013
Banned
 
Deafy's Avatar
 
Join Date: Jul 2013
Posts: 992
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 26
Thanked 100 Times in 95 Posts
(Thread Starter)
^^^^^^^^^^^^^^


Quote:
Originally Posted by Deafy View Post
Before the 'MCT' was introduced, what's the difference between the 7G transmission with 'AMG Speedshift' and all the other 7G units fitted to 171s?

Wikigoogle couldn't really satisfy my curiosity.
Deafy is offline  
#5 Old 10-28-2013
Registered Users
 
BarrySLK280's Avatar
 
Join Date: Aug 2013
Location: Kent, UK
Vehicle: 2009 MB SLK 280 Auto
Other Toys: Ford Fiesta 1.5Tdci Econetic Titanium
Posts: 790
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 13 Post(s)
Thanks: 26
Thanked 89 Times in 72 Posts
Garage
Smile

Quote:
Originally Posted by Deafy View Post
Tough question eh guys?
Ha ha....it appears you have us all completely stumped there Deafy!
BarrySLK280 is offline  
#6 Old 10-28-2013
Premium Member
 
randombloke's Avatar
 
Join Date: Mar 2013
Location: West Wales, UK
Vehicle: Gone: 2013 SLK 55 AMG
Posts: 771
Country:
Chats: 0
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Thanks: 72
Thanked 117 Times in 77 Posts
Garage
Quote:
Before the 'MCT' was introduced, what's the difference between the 7G transmission with 'AMG Speedshift' and all the other 7G units fitted to 171s?
Not sure if this helps your quest:

http://www.roadandtrack.com/car-revi...benz-slk55-amg

Quote:
AMG's V-8 develops 355 bhp and a hefty 376 lb.-ft. of torque and drives the rear wheels through M-B's new 7-speed automatic transmission, modified with AMG's SpeedShift fully adaptive program. Not only does it include Comfort and Sport modes, but also a Manual mode that can be operated sequentially either by moving the gear selector to the right or left, or by fingertip paddles behind the steering wheel (right for upshifts, left for downshifts).

AMG modifications to the transmission program include torque-converter lockup from 1st gear on, so that, once the car is running with no converter "cushion," throttle response is as quick throughout the range as with a manual transmission. Switching from Comfort to Sport not only raises the shift-up and shift-down speeds, but quickens the shift itself by up to 35 percent at the cost of only a slight loss of smoothness. A fairly hard application of the brakes also makes the transmission shift down into the appropriate gear, just as a driver would do with a manual transmission before negotiating a corner. Even in the automatic mode, the driver can manually select the gear of his choice.

The third mode is Manual, without any electronically governed intervention. There is no automatic downshift at low speed or an automatic upshift when the engine reaches its redline, and the kick-down remains inoperative.
Fwiw, the R172 slk 55 amg doesn't have MCT either:

http://www.mercedes-amg.com/slk55.php

Quote:
AMG SPEEDSHIFT PLUS 7G-TRONIC

Power is transferred to the rear wheels by means of the AMG SPEEDSHIFT PLUS 7G-TRONIC automatic transmission which features three transmission modes: "Controlled Efficiency" (C), Sport (S) and Manual (M). The automatic double-declutching function when downshifting as well as the brief, precisely defined interruption of ignition and injection when upshifting under full load shorten shifting times and increase emotional appeal when adopting a sporty driving style. A double turbine torsional damper with centrifugal pendulum which adapts to engine speed helps to minimise vibrations in four-cylinder operation and enhances the impression of comfort experienced by the vehicle occupants.

Gone: SLK 55 AMG (2013) Iridium Silver / Bengal Red / Black Ash
randombloke is offline  
#7 Old 10-28-2013
Banned
 
Deafy's Avatar
 
Join Date: Jul 2013
Posts: 992
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 26
Thanked 100 Times in 95 Posts
(Thread Starter)
^^^

Thanks random, best explanation I've seen so far.

The third mode is Manual, without any electronically governed intervention. There is no automatic downshift at low speed or an automatic upshift when the engine reaches its redline, and the kick-down remains inoperative.

I'm going to have to try this out. It implies you can hold a high gear and use the engine's torque, but I'm pretty sure that's not the case. That's my only real criticism of the 7G - it's desire to downshift at anything more than very light throttle. The improved shift times explains why I haven't found the transmission slow enough to warrant even considering a manual.

BTW, I've always wanted a 'double turbine torsional damper with centrifugal pendulum', so now I'm jealous.
randombloke likes this.
Deafy is offline  
#8 Old 10-28-2013
Premium Member
 
randombloke's Avatar
 
Join Date: Mar 2013
Location: West Wales, UK
Vehicle: Gone: 2013 SLK 55 AMG
Posts: 771
Country:
Chats: 0
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Thanks: 72
Thanked 117 Times in 77 Posts
Garage
Quote:
There is no automatic downshift at low speed
that doesn't sound right to me either as it would lead to stalling. It's certainly not the case with the R172 version as that downshifts automatically in manual mode when the rpm gets into stall territory.

Quote:
it's desire to downshift at anything more than very light throttle
same in the r172 too - neither manual nor sport auto fully hit the spot for me, but limiting the high gear in sport auto is the mode I've settled on. At least using that stops it hunting to 6th/7th on light throttle and then dropping down to 4th when the mere thought of pressing the throttle flashes across my mind.

In essence, I pretty much use the range limiting as a manual control over the way it works - at least it stops it hitting redline as much as it was in manual due to the slow reaction to paddle pulls.

In sport auto mode, it knows I've allowed it to go to a higher gear, but it still seems to hold onto the current gear for long enough to mean it isn't short shifting.

Quote:
BTW, I've always wanted a 'double turbine torsional damper with centrifugal pendulum', so now I'm jealous.

Gone: SLK 55 AMG (2013) Iridium Silver / Bengal Red / Black Ash
randombloke is offline  
#9 Old 10-29-2013
Banned
 
Deafy's Avatar
 
Join Date: Jul 2013
Posts: 992
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 26
Thanked 100 Times in 95 Posts
(Thread Starter)
So I played around with 'M' for a while today. Basically, it won't change up automatically (obviously), but it will progressively change down as the revs drop to abt 1200 rpm. In effect, it's quite a nice driving technique just changing up tapping the shifter or the button to get to the highest gear possible, as soon as possible, and then giving it a lot of foot to feel the torque of the engine. The only downside to this is that you 'might' ahem, find yourself doing 80 in a 40 due to the quiet, effortless tug from the V8. Also (I had read this), it starts in first in both forward and reverse, while in 'M'or 'S' which means there's a lot more creep at tickover than when in 'C'.
Deafy is offline  
Sponsored Links
Advertisement
 
Reply

  Lower Navigation
Go Back   Mercedes Benz SLK Forum > General Discussion about Mercedes Benz SLKs > AMGs

Bookmarks

Quick Reply
Message:
Options
Upload your files to MEGAUPLOAD
Upload your images to ImageShack

Register Now



In order to be able to post messages on the Mercedes Benz SLK Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
55 AMG, Dual clutch or not dual clutch? davidkn SLK R172 General Discussion 16 09-24-2015 11:14 PM
Explain S, C M shift modes nmslk SLK R171 General Discussion 16 12-23-2011 08:43 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome
 

Clubs, Garage Plus vBulletin Plugins by Drive Thru Online, Inc.