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-   -   Whats SMG exactly? (http://www.bimmerfest.com/forums/showthread.php?t=201747)

B_RASHED 04-22-2007 02:36 PM

Whats SMG exactly?
 
Hey guys i have a 98 528i but am looking to be getting a 2001-2003 m3 smg. but my question is whats smg. i have heard that its automatic with the manuel. when i say automatic i mean like driving my 528, no shifting required. can anybody fill me in. i wanted to know if smg is kinda equal to automatic but u also get the manuel with it. thanks guys.

04SMGM3 04-22-2007 04:07 PM

Not trying to sound rude, but before someone flames you for your question do a search here for SMG. Also you can google it and come up with some pretty in depth info on how it works. SMG is not an Automatic, it's a manual trans without a clutch pedal in the cab. clutching is controlled by the computer, you have different settings you can pick from to suit your driving pleasures. It does have a "D" drivelogic mode that allows the OBC to control the shifts, however it does get a little goofy at times. If not careful, it'll make you look like a total NOOb:mad: trying to drive a stick. In "S" mode(or "A". I'm going to start something here.) you control the shift either by the paddles on the steering wheel or by the stick on the console. There are different settings for both modes 1 thru 5 attainable in both or a S6 mode (manual shift only) with the DSC turned off. The difference being in 1 it shifts very smooth, almost to the point of boring(but it's an M, never boring.) and in 6 it will shift so fast gear to gear that you can pin your passangers head to the headrest. :D
I know I didn't go into full detail on the SMG but I hope this will help clear some stuff up for you. Happy hunting.
Jeff

mjames 04-22-2007 04:49 PM

Definitely not a manual. I came from steptronic and it's a whole different beast.

Boile 04-22-2007 05:12 PM

Quote:

Originally Posted by mjames (Post 2325227)
Definitely not a manual. I came from steptronic and it's a whole different beast.

Wrong.

It is a manual (that's the M in SMG), only without a clutch pedal.
The difference is that you use the paddles behind the steering wheel to shift. And you can only shift sequentially (from 2 to 3, 3 to 4, etc. No 2 to 4. That's the S in SMG).
Once the computer detects that you pushed the paddle, the clutch is activated hydraulically and the gear is shifted automatically for you. Because a computer serves as the "middle man", it's very natural to also offer a fully automated mode, where the computer takes over the entire operation and determines where and when to shift (much like how the Steptronic works). Perhaps this is what causes the misunderstanding. SMG is not an automatic transmission. There's no torque converter, like in the steptronic, so shifts are not as smooth. There is, however, a real clutch, like in the manual, but shifts happen faster and smoother than when operated by a typical human driver (the computer mimics an expert shifter, complete with rev matching and all).

razzy530 04-22-2007 05:22 PM

its a TRUE CLUTCHLESS Manual transmission. there are no other words to describe it OH? CAn you say FORMULA 1?

gbelton 04-22-2007 05:23 PM

Okay, One More Time...
 
Electrohydraulic manual transmission or clutchless manual gear system is a manual transmission system that works similar to a manual transmission but operates the clutch automatically. To change gears, the driver selects the desired gear, and the system automatically operates the clutch and throttle to match revs and engage the clutch again. Depending on the implementation, some transmissions will automatically shift gears at the right points and others require the driver to manually select the gear even when the engine is at the redline. Also, many such transmissions operate in sequential mode where the driver can only upshift or downshift by one gear at a time. Despite superficial similarity, clutchless manual transmission differ significantly in internal operation and driver's 'feel' from manumatics, which are automatic transmissions (using torque converter instead of clutch to manage the link between the transmission and the wheels) with ability to signal shifts manually.

Mercedes-Benz have named their system Sequentronic and BMW refer to their system SMG (Sequential Manual Gearbox; as used in the M3). The BMW SMG transmission has both automatic and manual shift modes. Inside the different modes there are different programs. The automatic programs range from A1 through A5, with the lower numbers representing slower and less agressive shifts. The manual shift mode ranges from S1 through S6, again with S1 for slower shifts and S6 for the quickest and most agressive shifts possible. Toyota also had a similar transmission on the MR2 Spyder, which is known as the Sequential Manual Transmission (SMT).

AzNMpower32 04-22-2007 05:52 PM

Think of it as a manual transmission, except there's a mechanism that takes care of the clutch for you. Don't expect it to drive like an AT.

An automatic doesn't qualify in the above statement because, well, there's a torque converter, which isn't the case with SMG.

cwsqbm 04-22-2007 07:48 PM

Quote:

Originally Posted by razzy530 (Post 2325284)
its a TRUE CLUTCHLESS Manual transmission. there are no other words to describe it OH? CAn you say FORMULA 1?

Incorrect. It has a clutch, and the clutch is disengaged for every shift up and down. A true clutchless transmission only needs the clutch for the launch from a standstill. The SMG transmission in the M3 is essentially the same transmission as the manual, just with computer controlling the shift forks and clutch.

SilverX3 04-22-2007 07:54 PM

so we know what S for, what M for .... so what G is for then ????

Cowboy Bebop 04-22-2007 11:16 PM

Jesus, Pay attention... S equential M anual G earbox!

This is the exact GETRAG 6 gearbox that is in the 3 pedal car.
This transmition is manual with a Hydraulically controled clutch.
It has a clutch, it has no clutch pedal.

04SMGM3 04-23-2007 04:58 AM

Quote:

Originally Posted by gbelton (Post 2325289)
Electrohydraulic manual transmission or clutchless manual gear system is a manual transmission system that works similar to a manual transmission but operates the clutch automatically. To change gears, the driver selects the desired gear, and the system automatically operates the clutch and throttle to match revs and engage the clutch again. Depending on the implementation, some transmissions will automatically shift gears at the right points and others require the driver to manually select the gear even when the engine is at the redline. Also, many such transmissions operate in sequential mode where the driver can only upshift or downshift by one gear at a time. Despite superficial similarity, clutchless manual transmission differ significantly in internal operation and driver's 'feel' from manumatics, which are automatic transmissions (using torque converter instead of clutch to manage the link between the transmission and the wheels) with ability to signal shifts manually.

Mercedes-Benz have named their system Sequentronic and BMW refer to their system SMG (Sequential Manual Gearbox; as used in the M3). The BMW SMG transmission has both automatic and manual shift modes. Inside the different modes there are different programs. The automatic programs range from A1 through A5, with the lower numbers representing slower and less agressive shifts. The manual shift mode ranges from S1 through S6, again with S1 for slower shifts and S6 for the quickest and most agressive shifts possible. Toyota also had a similar transmission on the MR2 Spyder, which is known as the Sequential Manual Transmission (SMT).



:bow:
Had I had more time yesturday, I would have gone into more detail. But I wouldn't have been able to put it like you did. Great info, I feel like a school kid again.

Bruce 04-23-2007 05:03 AM

The M stands for.....M. It does NOT stand for manual.

IIRC...the M stood for manual only on the original SMG on the E36 M3.

plien69 04-23-2007 07:31 AM

Quote:

Originally Posted by Bruce (Post 2325946)
The M stands for.....M. It does NOT stand for manual.

IIRC...the M stood for manual only on the original SMG on the E36 M3.

BMW is still calling it a Sequential Manual Gearbox:
http://www.bmwusa.com/vehicles/M/m6coupe/features.htm

Bruce 04-23-2007 11:48 AM

Well then, they keep changing their mind. Lots of naming convention stuff when they tried to do a lesser sequential gearbox for non M cars a few years ago. They offered them in the US for a year or two then stopped. Not sure if they still sell them in the ROW or not? That gearbox was supposed to be called the SMG, then they changed it to the SSG (Sequential sport gearbox) to not confuse it with the SMG 2 on the E46 M3.

plien69 04-23-2007 12:34 PM

Yeah, I wish they had kept on calling the units in the non-Ms "SSG." When they decided to call those "SMG" also, you had lots of confusion on SMG I, SMG II, SMG in the Ms, SMG in the non-Ms, etc.

mjames 04-23-2007 05:12 PM

I just want to clarify I MEANT it is definitely not an automatic. Doh! It is a whole different beast than an auto, which I came from. Don't expect it to drive like an auto, it doesn't. However, I have no regrets leaving the world of auto transmissions.

hackbagger 08-30-2012 08:43 PM

my SMG shifts all by itself when the indicator says "S" and must be manually shifted when it says "A" . this appears to be backwards...drives great but what gives?

OBS3SSION 08-31-2012 01:24 PM

Quote:

Originally Posted by Cowboy Bebop (Post 2325763)
Jesus, Pay attention... S equential M anual G earbox!

This is the exact GETRAG 6 gearbox that is in the 3 pedal car.
This transmition is manual with a Hydraulically controled clutch.
It has a clutch, it has no clutch pedal.

This!

Think of SMG as the same manual transmission as the 6-speed manual M3, except a robot will do the clutch and actuate the gear for you when you tap a paddle. A lot faster than you could ever do.

Quote:

Originally Posted by hackbagger (Post 7044693)
my SMG shifts all by itself when the indicator says "S" and must be manually shifted when it says "A" . this appears to be backwards...drives great but what gives?

See my answer on your other thread with the same question.


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