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Its an exciting time for mercedes. The w205 c class is really the first car mercedes has produced that you can easily "mod" and tune to get some serious gains. I am not talking about putting a 10 grand supercharger on my handbuilt engine here. I am talking about minimal investment for insane gains.
With great power, comes great wear and tear on the engine and components. I work for an automotive supplier to Daimler among others and we supply gearboxes, diffs, ptu,transmissions etc. Unfortunately the 9g tronic is a mercedes masterpiece and it was designed in house thus I have no info on it or tech specs from the engineering side.
These tunes (especially the v3 eurocharged tune) is really starting to make some power. On the engine side I believe I read we have forged internals and also it is used on other setups with more power and larger turbos. I am not sure we should be worried about engine issues. If someone has other information please chime in.
What I am concerned about is the transmission. Luckily I have found a few articles that spec the max input torque of the 9g. the only problem is that there are 2 published ratings. One is 700Nm (516 ft lbs) and one is 1000Nm (737 ft lbs). Links to articles below.
Keep in mind this is at the crank. So the wheel numbers are less by around 15% generally due to losses in the gearing. So with the v3 eurocharged tune at the crank it is most likely in the 560-580 ft lbs of torque.
My worry is because this exceeds one of the published ratings. If this rating is correct, these tunes are exceeding the capability of the gearbox and a failure is more likely.
So does anyone know the actual input torque rating to our 9g trannys in the c43? is it 700Nm or 1000Nm. If its 1000Nm we will be fine. But if its 700NM these tunes are over the limit.
. Tuners,, can anyone chime in? Do you have any actual fact? Or are you relying on the good customers you have to hopefully not have a problem and if they do hopefully they will let you know?
Have the 9g been updated to handle more power? The 9g was introduced in 2013. It is possible improvements have been made since then and now it is rated for 1000Nm compared to 700Nm when it came out.
If anyone has knowledge i would be interested to hear! I want to tune but dont want to put my car in a losing situation.
and for the 7g it shows 700/1000 Nm downstream fo torque converter. So it seems it may be possible to have more input torque than rated technically at crank. given they state the efficiency of the 9g torque converter is 93% or maybe 91%, this may put the rating of the v3 tune below spec just barely.
Its also possible there is a high performance and lower performance 9g as well. One with 700 input and one with 1000 input. Hopefully they put the better one in our cars. I wonder if there is a way to know.
2017 C43 AMG (W205), 2012 AM Vantage V12, 1989 964
Originally Posted by Star4life
in EPC my car shows W9Y500, maybe the american version is rated in ft lbs? or maybe thats the transfer unit rating. the tranny is 725.048
I believe it is 1000 NM.
"TRANSMISSION GEAR SYSTEM The gear layout of the 9G-Tronic, ➋, consists of four single planetary gear sets, six shift elements, three clutches and three brakes. With these elements, the 9G-Tronic has nine forward speeds and one reverse speed. The 9G-Tronic is designed for torques up to 1000 Nm. Compared with predecessor transmissions the 9G-Tronic is a complete new development and design. For a comfortable drive, harmonic gear steps and the high ratio of 9.15 are important. The ratio of the reverse gear was set between first and second gear. Thus smooth launches are possible, forward as well as backwards."
"Despite the two additional gears and a maximum transferable torque of 1000 Nm, the new transmission does not take more space than the 7 gears one and, furthermore, it is lighter than the previous one, with a weight of less than 100 kg."
"With the change in generation from the 7G-TRONIC to the 9G-TRONIC, the development engineers placed further emphasis on the area of “compact lightweight design”. Despite two additional gears and a maximum transferable torque of up to 1000 Nm, the new automatic transmission requires the same installation space as its predecessor, the 7G-TRONIC PLUS, and is also one kilogram lighter."
The 9G-TRONIC gearbox is lighter than the 7G-TRONIC seven-speed automatic unit and can work with RWD and 4MATIC layouts as well as in plug-in hybrid and full hybrid cars. Even though it has two more gears, it has just about the same size as the seven-speed transmission and can handle up to 1,000 Nm of torque. The 9G-Tronic is also capable of skipping “several gears” when needed."
"TRANSMISSION GEAR SYSTEM The gear layout of the 9G-Tronic, ➋, consists of four single planetary gear sets, six shift elements, three clutches and three brakes. With these elements, the 9G-Tronic has nine forward speeds and one reverse speed. The 9G-Tronic is designed for torques up to 1000 Nm. Compared with predecessor transmissions the 9G-Tronic is a complete new development and design. For a comfortable drive, harmonic gear steps and the high ratio of 9.15 are important. The ratio of the reverse gear was set between first and second gear. Thus smooth launches are possible, forward as well as backwards."
"Despite the two additional gears and a maximum transferable torque of 1000 Nm, the new transmission does not take more space than the 7 gears one and, furthermore, it is lighter than the previous one, with a weight of less than 100 kg."
"With the change in generation from the 7G-TRONIC to the 9G-TRONIC, the development engineers placed further emphasis on the area of “compact lightweight design”. Despite two additional gears and a maximum transferable torque of up to 1000 Nm, the new automatic transmission requires the same installation space as its predecessor, the 7G-TRONIC PLUS, and is also one kilogram lighter."
The 9G-TRONIC gearbox is lighter than the 7G-TRONIC seven-speed automatic unit and can work with RWD and 4MATIC layouts as well as in plug-in hybrid and full hybrid cars. Even though it has two more gears, it has just about the same size as the seven-speed transmission and can handle up to 1,000 Nm of torque. The 9G-Tronic is also capable of skipping “several gears” when needed."
Mercedes have always have various rated versions of their gearboxes. That is the max rating for that family of boxes.
in EPC my car shows W9Y500, maybe the american version is rated in ft lbs? or maybe thats the transfer unit rating. the tranny is 725.048
yes that is the 500nm version of the box.
Stock your car makes 384 lb-ft - 520nm.
520nm peak torque, with a 500nm continuous torque rated box. That's how mb have always done it.
For example, S65 AMG - 900nm rated 5g box - 1000nm peak torque.
You will wear the box more at higher torque outputs, but also keep in mind that there is torque management in the gearbox and power by gear so the gearbox will protect itself to a certain degree. Its a simple matter of more power/more tuning - more wear on the box.
Just got my Stage1 tune by AMR .. peak torque was 450ft-lb only between 2800-3200rpm, that equates to 610nm. If these trannys are only rated for 700nm thats still perfectly fine.
I find it hard to believe the gearbox is not rated for at least 1.5x the peak torque as most other stuff Daimler and other oems do.
MB never has boxes rated at 1.5x the peak torque output of their engines, its why they have 5+ versions of the boxes, unlike VAG etc who just have one box that can deal with all versions of their engines.
It is what it is, and your box is rated at what its rated for.
On the engine side I believe I read we have forged internals and also it is used on other setups with more power and larger turbos. I am not sure we should be worried about engine issues. If someone has other information please chime in.
This is not true. The connecting rod and piston assembly for the E43 engine has a different part number than the C43 engine. I can bet you an arm and leg that they beefed it up.
Just got my Stage1 tune by AMR .. peak torque was 450ft-lb only between 2800-3200rpm, that equates to 610nm. If these trannys are only rated for 700nm thats still perfectly fine.
Whats this dealer update on the dyno? First time seeing this.
This is a good thread. I have always wondered about the transmission on our cars.
Originally Posted by SkitsversuS
Just got my Stage1 tune by AMR .. peak torque was 450ft-lb only between 2800-3200rpm, that equates to 610nm. If these trannys are only rated for 700nm thats still perfectly fine.
Dammnnnnnnn that torque stays above 425tq for over 2200rpm span!
Honestly, you seem more like a fake account made by AMR haha. Wouldn't be hard to prove, the forum tracks all your posts.
Lol how do you even get that from this? All he did was compliment the dyno sheet (which was worth a comment, great power!). I have seen you troll in other posts, so the same could be said with favoritism. Everyone is partial to a brand or product, so it is a waste of time to try and call someone out on it.
Yeah I am the troll. Just compare your contribution in mbworld with mine to keep it simple. Before I thought you guys just sucked at tuning, now it appears you guys are idiots too. The forum tracks everything haha. One click and I can see all your previous posts. Anyhoo, moving on.
New 9G Tronic Transmission Has Maximum Input Torque of 700 Nm or 516 lb ft
The New 9G Tronic Transmission apparently has a maximum input torque of 700 Nm or 516 lb ft, which is not by coincidence the maximum engine torque of Mercedes M278 twin turbo 4.6 liter V8,
which is probably the strongest torque application this new 9G Tronic Transmission will be paired to.
Refer to the pdf document below, Technical Data, Max Input Torque 700 Nm http://assets.mbusa.com/vcm/CAC_RAPM...heworkshop.pdf
What OC43AMG found referring to maximum transferable torque of 1000 Nm (752 lb ft) may imply that the 9G tronic Transmission is capable of the higher torque transfer in higher gears
where torque multiplication from gearing is far less than in first gear, where gear ratio and thus torque multiplication is highest, and the transmission clutches and bands can simply not handle such high torque in first gear.
Note that in the attached document for the old 7G Tronic Transmission, "the maximum sustainable transfer capacity of transmission input coupling downstream of converter:"
is similarly 700/1000 Nm as the new 9G Tronic.
The 9G tronic is most likely limited by first gear where torque multiplication is massive because of its 5.5:1 First Gear Ratio.
If 700 Nm (516 lb ft) of torque input from the engine were to be exceeded in first gear, 1st gear transmission clutches and bands would start slipping and wearing, eventually destroying the transmission.
Mercedes relies on Engine Torque Management from the computer to never deliver more torque from the engine than the transmission can handle in any gear. If a tuner is unaware of the transmission torque limitations in every gear of the transmission, and exceeds max torque any gear can handle, transmission damage and failure can occur.
Thus it is vital to use a reputable and knowledgeable tuner even if it means you cant do a smokey 4matic burnout in 1st gear with your S550 Benz.
Multiplying 1st Gear Ratio By Maximum Input Torque in the 9G Tronic, we have 5.502 X 516 lb ft = 2839 lb ft of output torque from transmission (minus some losses)
Multiplying 1st Gear Ratio By Maximum Input Torque in the 7G Tronic we have 4.377 X 516 lb ft = 2,258 lb ft of output torque from the transmission
Thus we have an additional 581 lb ft of Transmission Output Torque in 1st Gear (approx 25% more) with the new 9G versus the old 7G tronic that will be used for faster acceleration from the line. (given equal final drive (axle) ratios)
Even though both the old 7G and new 9G transmissions have a maximum input torque limit of 700 Nm (516 lb ft), the new 9G Tronic Mercedes Transmission Gives cars equipped with it a solid and measurable acceleration performance advantage
because of the approximately 25% greater torque multiplication the 9G has over the 7G, due to its superior first gear ratio. 2nd and 3rd ratios are also higher and better for acceleration performance
Therefore, the new Mercedes 9G Tronic Transmission is Superior in Acceleration Performance to the 7G Tronic Transmission
Its like I am invisible here. There are different versions with different ratings. Stop reading marketing blurbs that refer to the design as a whole and not the specific version in your cars. Rating is as the input shaft downstream of the converter.
01-25-2018, 11:47 AM
