DCT - BMW 3-Series (E90 E92) Forum

ChubbsBmth · 03-14-2012, 02:28 PM

In reasonably simplistic terms could anyone explain the difference/benefits of DCT over the normal Auto box.

Anyone with experience of the DCT box care to share their experiences of driving with it?

Thanks

The_Bear_Yid · 03-14-2012, 03:31 PM

Dual clutches are better than one.

That simple enough?

Bungle009 · 03-14-2012, 03:37 PM

Immediate changes, gear pre-selection, no torque converter so much more dynamic.

seanblee · 03-14-2012, 03:48 PM

DCT is like having two gearboxes - one has the odd gears and the other has the even. When it changes gear, it effectively disengages the clutch on one and engages it on the other at the same time, so the shifts are practically instant. Normal autos have to disengage one gear then engage the next, so they shift slower.

Advantages are better fuel economy (as it's not slipping the clutch except when pulling away) and better performance. The only real disadvantages are that some are badly behaved when manuevering (though I haven't heard any complaints about the box that BMW use) and they're even more complicated than a conventional automatic.

RagingKileak · 03-14-2012, 04:04 PM

The technical side seems to be covered so all I can add is the way it feels vs the standard BMW auto.

It's quicker, it's similarly smooth and it's actually got a decent sport mode. Having 7 gears is also a good conversation piece down the pub!

I'm expecting a big bill if it breaks...

Matt

rickyjones1209 · 03-14-2012, 04:05 PM

I really wish I could afford a DCT 335i it sounds like a mint bit of kit. I don't really even want to drive one coz I know it'll piss me off knowing I'll have to 'make do' with the step tronic. I only hope that the step box is as good as I hope it will be. I'm not expecting miracles but just smooth, fairly fast changes.

How much do decent spec DCT 335i's go for now? Must still be over 20k.

rickyjones1209 · 03-14-2012, 04:08 PM

Quote:

Originally Posted by rickyjones1209

I really wish I could afford a DCT 335i it sounds like a mint bit of kit. I don't really even want to drive one coz I know it'll piss me off knowing I'll have to 'make do' with the step tronic. I only hope that the step box is as good as I hope it will be. I'm not expecting miracles but just smooth, fairly fast changes.

How much do decent spec DCT 335i's go for now? Must still be over 20k.

Quick search suggests more like 25k

ChubbsBmth · 03-14-2012, 04:12 PM

Sounds like an amazing bit of kit.

Quite glad they seem to go for so much though as would of been out of my price bracket.

RagingKileak · 03-14-2012, 06:11 PM

Sorry for the shameless plug, but it sounds to me like you guys should check out my new car thread here...

http://www.e90post.com/forums/showthread.php?t=653416

I've recently bought a mint, DCT, twin turbo 335i with the HDD based Nav and in a great colour combo for around 24k. I'll be doing a lot of write ups including about the DCT box so check it out.

Matt

uke92dude · 03-14-2012, 06:17 PM

Interestingly though, the new 335i saloon has the new 8 speeder NOT DCT fitted. Don't think it's an option either...?

ss134 · 03-14-2012, 06:50 PM

Quote:

Originally Posted by uke92dude

Interestingly though, the new 335i saloon has the new 8 speeder NOT DCT fitted. Don't think it's an option either...?

DCT was never an option on E90 generation 335i saloon either - was only available on the coupe so it looks like BMW may stick to the same formula when the F32 is available.

Jon D · 03-14-2012, 09:36 PM

Basic operation and schematic here:
http://auto.howstuffworks.com/dual-c...ansmission.htm

Dannyrado · 03-15-2012, 03:02 AM

I've missed the boat on this one. Anyone know when they started fitting them?

Did they just go in the 335i and M3, or is there the opertunity to buy a used, say 330d with DCT? I'm guessing since they aint in the E90, they won't be in the E91 either??

uke92dude · 03-15-2012, 03:04 AM

Quote:

Originally Posted by ss134

DCT was never an option on E90 generation 335i saloon either - was only available on the coupe so it looks like BMW may stick to the same formula when the F32 is available.

Ahhh yes of course - it was late - doh!

creepy coupe · 03-15-2012, 03:12 AM

Quote:

Originally Posted by Dannyrado

I've missed the boat on this one. Anyone know when they started fitting them?

Did they just go in the 335i and M3, or is there the opertunity to buy a used, say 330d with DCT? I'm guessing since they aint in the E90, they won't be in the E91 either??

Around mid to late 2008. 335i and M3 at the time

chedixon · 03-15-2012, 03:38 AM

I had a DSG box in my last car and it was brilliant. If they did a dct in the engine I went fori would have gone for it for sure. I test drove a normal auto in the 2.0d and it was ok although not nearly as good as a twin clutch. Saying that though the manual box is pretty crap so if I had the choice again I'd have gone for the auto. Sure the dct would be superb though

Guvernator · 03-15-2012, 07:32 AM

Quote:

Originally Posted by rickyjones1209

I really wish I could afford a DCT 335i it sounds like a mint bit of kit. I don't really even want to drive one coz I know it'll piss me off knowing I'll have to 'make do' with the step tronic. I only hope that the step box is as good as I hope it will be. I'm not expecting miracles but just smooth, fairly fast changes.

How much do decent spec DCT 335i's go for now? Must still be over 20k.

If it's smooth and fast you want the normal step auto is more than adequate, I'd say it's probably one of the best auto boxes I have tried in that respect. In fact it's probably too good in that even in manual mode, it smoothes out the gear changes to such an extend that it actually detracts from the dynamism and feeling of being fully in control of the car. That is the only complaint I could level against the auto.

rickyjones1209 · 03-15-2012, 09:35 AM

Quote:

Originally Posted by Guvernator

If it's smooth and fast you want the normal step auto is more than adequate, I'd say it's probably one of the best auto boxes I have tried in that respect. In fact it's probably too good in that even in manual mode, it smoothes out the gear changes to such an extend that it actually detracts from the dynamism and feeling of being fully in control of the car. That is the only complaint I could level against the auto.

Thats good to hear. I'm driving one on Sunday so looking forward to putting it to the test.

Can anyone tell me how the step tronic compares to the smg box in the old m3? I understand the mechanics around it but in practice how does the step feel against the smg when driving quickly though the gears? Faster, slower, smoother, jerkier?

RagingKileak · 03-15-2012, 10:39 AM

The SMG is more alike to the DCT than the standard Auto mate. It's far more aggressive, jerky and aggressive than the one you will drive, but also quicker.

BMW autos are VERY good, they are just not especially sporty. Expect smoothness but little excitement.

Matt

creepy coupe · 03-15-2012, 11:02 AM

And clunky and nasty

AlanQS · 03-15-2012, 11:15 AM

The DCT came out on M3 and E92 (plus convertible versions) from March 2009.

takumichinoku · 03-15-2012, 09:25 PM

With reference to the OP question. DCT is amazing! Super quick shifts that aren't even noticeable. I actually don't think I could go back to anything else! Amazing gearbox!

03-14-2012, 02:28 PM	#1
ChubbsBmth Second Lieutenant Drives: 335i M-Sport Join Date: Oct 2011 Location: Bournemouth Posts: 246 iTrader: (0)	DCT In reasonably simplistic terms could anyone explain the difference/benefits of DCT over the normal Auto box. Anyone with experience of the DCT box care to share their experiences of driving with it? Thanks __________________ E92 May 07' 335i M-Sport - Sapphire Black - Manual - Black Leather Interior - Heated Seats - Bluetooth Handsfree - BMW Performance Black Grill - 19's - Saying No to the Diesel Revolution!
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03-14-2012, 03:48 PM	#4
seanblee Captain Drives: E92 335i SE Join Date: Dec 2008 Location: Enfield, UK Posts: 658 iTrader: (1)	DCT is like having two gearboxes - one has the odd gears and the other has the even. When it changes gear, it effectively disengages the clutch on one and engages it on the other at the same time, so the shifts are practically instant. Normal autos have to disengage one gear then engage the next, so they shift slower. Advantages are better fuel economy (as it's not slipping the clutch except when pulling away) and better performance. The only real disadvantages are that some are badly behaved when manuevering (though I haven't heard any complaints about the box that BMW use) and they're even more complicated than a conventional automatic. __________________ 2007 E92 335i SE auto \| Monaco Blue \| Cream Beige \| Quaife LSD \| Birds B3 ARBs \| Evolve Stage 1 \| CIC retrofit

03-14-2012, 04:12 PM	#8
ChubbsBmth Second Lieutenant Drives: 335i M-Sport Join Date: Oct 2011 Location: Bournemouth Posts: 246 iTrader: (0)	Sounds like an amazing bit of kit. Quite glad they seem to go for so much though as would of been out of my price bracket. __________________ E92 May 07' 335i M-Sport - Sapphire Black - Manual - Black Leather Interior - Heated Seats - Bluetooth Handsfree - BMW Performance Black Grill - 19's - Saying No to the Diesel Revolution!

03-15-2012, 03:02 AM	#13
Dannyrado First Lieutenant Drives: 335d m sport coupe Join Date: May 2009 Location: N Wales Posts: 372 iTrader: (0)	I've missed the boat on this one. Anyone know when they started fitting them? Did they just go in the 335i and M3, or is there the opertunity to buy a used, say 330d with DCT? I'm guessing since they aint in the E90, they won't be in the E91 either?? __________________ E46 M3 SMG titanium silver, with grey leather. 335d now gone. 2010 Golf estate bluemotion, spec'd up and not nearly as bad as it sounds. & 2011 Citroen C4 e-hdi airdream, Missus's car.

03-15-2012, 03:38 AM	#16
chedixon Second Lieutenant Drives: E93 320d Msport Join Date: Aug 2011 Location: Nottingham Posts: 252 iTrader: (1)	I had a DSG box in my last car and it was brilliant. If they did a dct in the engine I went fori would have gone for it for sure. I test drove a normal auto in the 2.0d and it was ok although not nearly as good as a twin clutch. Saying that though the manual box is pretty crap so if I had the choice again I'd have gone for the auto. Sure the dct would be superb though __________________ E93 320d Msport If it ain't raining, the roof is down

03-14-2012, 03:31 PM	#2
The_Bear_Yid BM Noob Drives: E92 325i Join Date: Mar 2011 Location: Kent Posts: 743 iTrader: (0)	Dual clutches are better than one. That simple enough?

03-14-2012, 03:37 PM	#3
Bungle009 Lieutenant Drives: E92 M3 Join Date: Nov 2009 Location: Alton Posts: 579 iTrader: (0)	Immediate changes, gear pre-selection, no torque converter so much more dynamic.

03-14-2012, 04:04 PM	#5
RagingKileak Brigadier General Drives: Modified Alpine White E92 335i Join Date: Jan 2009 Location: Yorkshire Posts: 4,308 iTrader: (1)	The technical side seems to be covered so all I can add is the way it feels vs the standard BMW auto. It's quicker, it's similarly smooth and it's actually got a decent sport mode. Having 7 gears is also a good conversation piece down the pub! I'm expecting a big bill if it breaks... Matt

03-14-2012, 04:05 PM	#6
rickyjones1209 First Lieutenant Drives: 2008 e92 335i Join Date: Jan 2012 Location: Cheshire Posts: 330 iTrader: (1)	I really wish I could afford a DCT 335i it sounds like a mint bit of kit. I don't really even want to drive one coz I know it'll piss me off knowing I'll have to 'make do' with the step tronic. I only hope that the step box is as good as I hope it will be. I'm not expecting miracles but just smooth, fairly fast changes. How much do decent spec DCT 335i's go for now? Must still be over 20k.

03-14-2012, 06:11 PM	#9
RagingKileak Brigadier General Drives: Modified Alpine White E92 335i Join Date: Jan 2009 Location: Yorkshire Posts: 4,308 iTrader: (1)	Sorry for the shameless plug, but it sounds to me like you guys should check out my new car thread here... http://www.e90post.com/forums/showthread.php?t=653416 I've recently bought a mint, DCT, twin turbo 335i with the HDD based Nav and in a great colour combo for around 24k. I'll be doing a lot of write ups including about the DCT box so check it out. Matt

03-14-2012, 06:17 PM	#10
uke92dude - Drives: E92 Join Date: Dec 2008 Location: UK Posts: 802 iTrader: (0)	Interestingly though, the new 335i saloon has the new 8 speeder NOT DCT fitted. Don't think it's an option either...?

03-14-2012, 09:36 PM	#12
Jon D Colonel Drives: F12 640i Join Date: Sep 2009 Location: Scotland Posts: 2,516 iTrader: (0)	Basic operation and schematic here: http://auto.howstuffworks.com/dual-c...ansmission.htm

03-15-2012, 10:39 AM	#19
RagingKileak Brigadier General Drives: Modified Alpine White E92 335i Join Date: Jan 2009 Location: Yorkshire Posts: 4,308 iTrader: (1)	The SMG is more alike to the DCT than the standard Auto mate. It's far more aggressive, jerky and aggressive than the one you will drive, but also quicker. BMW autos are VERY good, they are just not especially sporty. Expect smoothness but little excitement. Matt

03-15-2012, 11:02 AM	#20
creepy coupe Major General Drives: 635d Join Date: Aug 2007 Location: UK Posts: 7,564 iTrader: (2) Garage List 2009 335i [0.00]	And clunky and nasty

03-15-2012, 11:15 AM	#21
AlanQS Colonel Drives: 320d SE Coupe Join Date: Jan 2008 Location: Glasgow Posts: 2,447 iTrader: (0) Garage List 2008 320d SE Coupe [0.00]	The DCT came out on M3 and E92 (plus convertible versions) from March 2009. __________________

03-15-2012, 09:25 PM	#22
takumichinoku Private Drives: 335i Join Date: Feb 2012 Location: UK Posts: 64 iTrader: (0)	With reference to the OP question. DCT is amazing! Super quick shifts that aren't even noticeable. I actually don't think I could go back to anything else! Amazing gearbox!

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