SMG vs DSG
- Thread starter joshdway
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KT
Well-Known Member
Re: SMG vs DSG
Here is my layman explanation. For DSG, it uses 2 sets of clutch plates. Gear 1,3, 5 on one and 2,4,6 on the other.
When you are on 1st gear, for example, 2nd gear is already pre-selected, so when it shifts, it just drop in, and cog shift is achieved. The entire shift process is said to complete in 3 to 4 hundredths of a second. The whole assembly is sealed in oil to keep it cool, it was hence sometimes called wet-clutches.
VW claimed that DSG shifts better than manual and the 0-100 timing for DSG is 0.3 sec faster as well. I timed mine on G-tech, it clocked 6.3 sec consistently on a hot Sunday afternoon after about 4 continuous runs.
Here is my layman explanation. For DSG, it uses 2 sets of clutch plates. Gear 1,3, 5 on one and 2,4,6 on the other.
When you are on 1st gear, for example, 2nd gear is already pre-selected, so when it shifts, it just drop in, and cog shift is achieved. The entire shift process is said to complete in 3 to 4 hundredths of a second. The whole assembly is sealed in oil to keep it cool, it was hence sometimes called wet-clutches.
VW claimed that DSG shifts better than manual and the 0-100 timing for DSG is 0.3 sec faster as well. I timed mine on G-tech, it clocked 6.3 sec consistently on a hot Sunday afternoon after about 4 continuous runs.
Physicist
Well-Known Member
Re: SMG vs DSG
DSG shifts faster than SMG II. Theoretically, you don't need to release the accelerator pedal when up-shifting for SMG II but I found that the shift process is more smooth if you do that.
You don't need to release accelerator pedal when up-shifting for DSG.
DSG shifts faster than SMG II. Theoretically, you don't need to release the accelerator pedal when up-shifting for SMG II but I found that the shift process is more smooth if you do that.
You don't need to release accelerator pedal when up-shifting for DSG.
piggyboyz
Core Group Members
Re: SMG vs DSG
So much said for the DSG, maybe i just explain a little on SMG just in case the thread initiator still unaware how SMG function.
SMG is effectively a manual gearbox but the clutch when upshifting / downshifting is controlled hydraulically via the paddles on the wheel.
Theoretically, both DSG and SMG needs initialisation or adaptation since the control unit will need to measure the gap for complete clutch contact and off-contact. this test is done when there is a clutch replacement.
Unlike the DSG, which is a twin clutch, completely submerged in oil for cooling, the SMG is really just a conventional manual clutch system that uses only single clutch.
DSG is supposingly the improved version of the SMG. Correct me if i am wrong but from what i know, the current Golf GTi changes gear at 0.3sec ? which is slightly faster than the BMW SMG system but the M3 SMGII changes gear at a lightning speed of 0.07sec, so the M3 is still faster in terms of shifting.
The SMG changes gear with a tuck but the DSG is as good as a automatic, changing seamslessly. Both r fun and somehow, i enjoy the tuck and the knock on the gearbox whenever i pedal the car to the metal and see the car lurge forward. The GTi creeps forward when u engage gears and I associates that with automatic but i supposed they have to do it that way to get rid of the jerk when moving off..
BMW is supposingly coming with their version of the DSG as well and it's definitely going to take over the current automatic transmission someday.. Enticing i must say..
So much said for the DSG, maybe i just explain a little on SMG just in case the thread initiator still unaware how SMG function.
SMG is effectively a manual gearbox but the clutch when upshifting / downshifting is controlled hydraulically via the paddles on the wheel.
Theoretically, both DSG and SMG needs initialisation or adaptation since the control unit will need to measure the gap for complete clutch contact and off-contact. this test is done when there is a clutch replacement.
Unlike the DSG, which is a twin clutch, completely submerged in oil for cooling, the SMG is really just a conventional manual clutch system that uses only single clutch.
DSG is supposingly the improved version of the SMG. Correct me if i am wrong but from what i know, the current Golf GTi changes gear at 0.3sec ? which is slightly faster than the BMW SMG system but the M3 SMGII changes gear at a lightning speed of 0.07sec, so the M3 is still faster in terms of shifting.
The SMG changes gear with a tuck but the DSG is as good as a automatic, changing seamslessly. Both r fun and somehow, i enjoy the tuck and the knock on the gearbox whenever i pedal the car to the metal and see the car lurge forward. The GTi creeps forward when u engage gears and I associates that with automatic but i supposed they have to do it that way to get rid of the jerk when moving off..
BMW is supposingly coming with their version of the DSG as well and it's definitely going to take over the current automatic transmission someday.. Enticing i must say..
T6
Well-Known Member
Re: SMG vs DSG
Piggy,
I think the DSG gear change is faster than that. More like 3 or 4 hundredths of a second. See the following from an online article:
Transmission: DSG (Direct Shift Gearbox)
DSG is a manual gearbox in which the gearshifts are controlled electronically. What makes the DSG unique is that it has 2 separate gear sets operated by 2 wet multi-plate clutches (1st, 3rd, 5th on one gear set, plus 2nd, 4th, 6th on the other).
The benefit of 2 gear sets and 2 multi-plate wet clutches is that one gear set and clutch is engaged driving the vehicle with the second clutch having already pre-selected the next gear awaiting for power to be transferred.
As the next gear has already been preselected prior to power being applied, the gear change only takes 3 to 4 hundredths of a second. There is virtually no interruption to power, traction or acceleration.
piggyboyz said:
Piggy,
I think the DSG gear change is faster than that. More like 3 or 4 hundredths of a second. See the following from an online article:
Transmission: DSG (Direct Shift Gearbox)
DSG is a manual gearbox in which the gearshifts are controlled electronically. What makes the DSG unique is that it has 2 separate gear sets operated by 2 wet multi-plate clutches (1st, 3rd, 5th on one gear set, plus 2nd, 4th, 6th on the other).
The benefit of 2 gear sets and 2 multi-plate wet clutches is that one gear set and clutch is engaged driving the vehicle with the second clutch having already pre-selected the next gear awaiting for power to be transferred.
As the next gear has already been preselected prior to power being applied, the gear change only takes 3 to 4 hundredths of a second. There is virtually no interruption to power, traction or acceleration.
KT
Well-Known Member
Re: SMG vs DSG
For me, it would the exhaust burpping at me when you floor the fellow, to me that is what you pay a GTi for. You can hardly feel the gear change but in normal drive mode, it just go. In 'S', it is a different story though. I do not enjoy driving in S but I have buddy who is always in that mode for filtering lane .. he likes to say he could "jump" in front of otheres in that mode.
piggyboyz said:
For me, it would the exhaust burpping at me when you floor the fellow, to me that is what you pay a GTi for. You can hardly feel the gear change but in normal drive mode, it just go. In 'S', it is a different story though. I do not enjoy driving in S but I have buddy who is always in that mode for filtering lane .. he likes to say he could "jump" in front of otheres in that mode.
Re: SMG vs DSG
do you need to manually shift gear (1-2-3) when doing launch control on the GTi?
on the M3, you need, clutch drop at about 4krpm!!
from verious magazines and reviews, most agree that DSG is a better overall implementation than the SMG.
Also rumor that Porsche will be implementing DSG in some of their models in '07.
do you need to manually shift gear (1-2-3) when doing launch control on the GTi?
on the M3, you need, clutch drop at about 4krpm!!
from verious magazines and reviews, most agree that DSG is a better overall implementation than the SMG.
Also rumor that Porsche will be implementing DSG in some of their models in '07.
