M-DCT question!

sehrgut · 11-30-2009, 03:15 PM

My dad has a 2008 E60 M5 SMG and on that one whenever its driven you have to let of a little gas when shifting in manual mode. When I bought my E92 M3 the salesguy told me that these trannys can handle paddleshifting without letting of the gas (beauty with DCT or something) and that these trannys can take pretty much abuse. Only downside apparently was the lag, unless sportmode or updated software.

I'm just concered considering my dad had to change change the SMG clutch after only 16k miles. But its been driven hard.

Thanks

URBAN LEGEND · 11-30-2009, 03:35 PM

No lift shift for 15000 miles and counting. DCT FTW again.

M3ltdown · 11-30-2009, 03:40 PM

yup... full throttle shifting.

waremark · 11-30-2009, 05:00 PM

DCT is completely different from SMG. DCT is quite certainly designed for full throttle upshifts without lifting.

The comparison between different shift modes is interesting. I did acceleration runs in my car with a logger, and compared S1 to S6. You might be surprised to know that the acceleration times were the same - in S1 you get continuous acceleration, in S4 and above you get a slight gap in the acceleration, then a surge which catches up. Following this, I have always used my car in S1 because I do not like the feel of the surge on upshifts. Ideally I would like S4 downshifts with a blip, combined with S1/S2 smooth upshifts, but sadly that is not possible.

Finnegan · 11-30-2009, 05:18 PM

Quote:

Originally Posted by waremark

DCT is completely different from SMG. DCT is quite certainly designed for full throttle upshifts without lifting.

The comparison between different shift modes is interesting. I did acceleration runs in my car with a logger, and compared S1 to S6. You might be surprised to know that the acceleration times were the same - in S1 you get continuous acceleration, in S4 and above you get a slight gap in the acceleration, then a surge which catches up. Following this, I have always used my car in S1 because I do not like the feel of the surge on upshifts. Ideally I would like S4 downshifts with a blip, combined with S1/S2 smooth upshifts, but sadly that is not possible.

S4 downshifts with S1/S2 upshifts....that would be very nice. Seems they ought to be able to code that. I'd give up S3 or S5 to have that mix of upshift/downshift programs.

Vic55 · 11-30-2009, 05:37 PM

Owned an M6 for 2 years, no lift needed ever under any map...check out the M5Board.com for tons of info on this subject regarding SMG.

As for the DCT- no lifting also.

chrisburns · 11-30-2009, 05:39 PM

Quote:

Originally Posted by Vic55

Owned an M6 for 2 years, no lift needed ever under any map...check out the M5Board.com for tons of info on this subject regarding SMG.

As for the DCT- no lifting also.

Having owned an M5 for slightly longer, this man speaks the truth.

sehrgut · 12-01-2009, 04:04 AM

Really good input guys, I guess I can drive it shifting at full throttle without me being worried

And for Vic55, hands down you got one amazing car collection.

jamie · 12-01-2009, 05:02 AM

Quote:

Originally Posted by Vic55

Owned an M6 for 2 years, no lift needed ever under any map...check out the M5Board.com for tons of info on this subject regarding SMG.

As for the DCT- no lifting also.

Had an M5 and two M6's. Never lifted when shifting.

Toodeep · 12-01-2009, 05:35 AM

DCT has two clutches, one for the even gears and another for the odd ones so the clutch for the gear up or down from where you are can be engaged at almost the exact moment the previous gear disengages. It even makes a guess as to which gear to get ready. SMG has just one clutch so the need to lift off is the same as the need to do so with a manual transmission which is all it is. The difference is that the electronics can disengage and engage the SMG clutch much more quickly than a human could deploy a clutch pedal so you end up needing to lift off nowhere near as long.

waremark · 12-01-2009, 01:06 PM

Quote:

Originally Posted by Vic55

Owned an M6 for 2 years.....

How do you decide which car to take out?

ISF and M3 - how do they compare in your opinion? What about DCT vs the ISF 8 speed auto?

Cabinetman · 12-01-2009, 02:10 PM

Quote:

Originally Posted by waremark

How do you decide which car to take out?

ISF and M3 - how do they compare in your opinion? What about DCT vs the ISF 8 speed auto?

I used to own an IS-F and posted my comparison of the two cars on clublexus. You can read it here: http://www.clublexus.com/forums/is-f...vs-f-long.html

bknight · 12-01-2009, 02:20 PM

Quote:

Originally Posted by Cabinetman

I used to own an IS-F and posted my comparison of the two cars on clublexus. You can read it here: http://www.clublexus.com/forums/is-f...vs-f-long.html

that was a really informative read, good write-up.

waremark · 12-01-2009, 05:32 PM

Quote:

Originally Posted by Cabinetman

I used to own an IS-F and posted my comparison of the two cars on clublexus. You can read it here: http://www.clublexus.com/forums/is-f...vs-f-long.html

Excellent comparison, thanks.

sehrgut · 12-02-2009, 02:17 AM

Nicely done writeup, the IS-F is definitely lexus pride and joy

.

BPMSport · 12-02-2009, 03:24 AM

No lifting with M5 or M6. You could make the shifts much smoother by lifting in less spirited driving situations.

DCT has less of a *bang* and is slightly quicker due to the dual clutch. Our software makes the M5/M6 shift much better.

11-30-2009, 03:15 PM	#1
sehrgut Major 33 Rep 1,033 Posts Drives: emthree Join Date: Oct 2009 Location: socal iTrader: (1)	M-DCT question! My dad has a 2008 E60 M5 SMG and on that one whenever its driven you have to let of a little gas when shifting in manual mode. When I bought my E92 M3 the salesguy told me that these trannys can handle paddleshifting without letting of the gas (beauty with DCT or something) and that these trannys can take pretty much abuse. Only downside apparently was the lag, unless sportmode or updated software. I'm just concered considering my dad had to change change the SMG clutch after only 16k miles. But its been driven hard. Thanks Last edited by sehrgut; 12-02-2009 at 02:15 AM..
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11-30-2009, 03:35 PM	#2
URBAN LEGEND Rocky 413 Rep 3,085 Posts Drives: 16 M5, 18 ZL1 1LE, 18 M3 Join Date: Feb 2009 Location: Brenham TX iTrader: (0)	No lift shift for 15000 miles and counting. DCT FTW again. __________________ 22 Audi RS E-Tron GT 21 Model S Plaid
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11-30-2009, 03:40 PM	#3
M3ltdown Master Chief 19 Rep 641 Posts Drives: 09 e90 M3 JzB Join Date: Jul 2008 Location: NOVA iTrader: (0)	yup... full throttle shifting.
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11-30-2009, 05:00 PM	#4
waremark Private First Class 2 Rep 183 Posts Drives: 08 M3 Coupe DCT Join Date: Nov 2008 Location: UK iTrader: (0)	DCT is completely different from SMG. DCT is quite certainly designed for full throttle upshifts without lifting. The comparison between different shift modes is interesting. I did acceleration runs in my car with a logger, and compared S1 to S6. You might be surprised to know that the acceleration times were the same - in S1 you get continuous acceleration, in S4 and above you get a slight gap in the acceleration, then a surge which catches up. Following this, I have always used my car in S1 because I do not like the feel of the surge on upshifts. Ideally I would like S4 downshifts with a blip, combined with S1/S2 smooth upshifts, but sadly that is not possible.
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11-30-2009, 05:37 PM	#6
Vic55 Lieutenant General 19650 Rep 10,214 Posts Drives: 2023 BMW M8 Competition Coupe Join Date: Jul 2009 Location: THE Orange County iTrader: (9)	Owned an M6 for 2 years, no lift needed ever under any map...check out the M5Board.com for tons of info on this subject regarding SMG. As for the DCT- no lifting also. __________________ 2024 BMW M3 CS Frozen Solid White 2023 BMW M8 Coupe Competition Alpine White 2022 Porsche Carrera GTS Coupe Shark Blue 2020 Audi R8 V10 Performance Suzuka Gray 2012 Mercedes Benz C63 AMG Black Series Obsidian Black
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12-01-2009, 04:04 AM	#8
sehrgut Major 33 Rep 1,033 Posts Drives: emthree Join Date: Oct 2009 Location: socal iTrader: (1)	Really good input guys, I guess I can drive it shifting at full throttle without me being worried And for Vic55, hands down you got one amazing car collection.
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12-01-2009, 05:35 AM	#10
Toodeep Enlisted Member 0 Rep 44 Posts Drives: sDrive 35i DCT Join Date: Nov 2009 Location: London, England iTrader: (0)	DCT has two clutches, one for the even gears and another for the odd ones so the clutch for the gear up or down from where you are can be engaged at almost the exact moment the previous gear disengages. It even makes a guess as to which gear to get ready. SMG has just one clutch so the need to lift off is the same as the need to do so with a manual transmission which is all it is. The difference is that the electronics can disengage and engage the SMG clutch much more quickly than a human could deploy a clutch pedal so you end up needing to lift off nowhere near as long.
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12-02-2009, 02:17 AM	#15
sehrgut Major 33 Rep 1,033 Posts Drives: emthree Join Date: Oct 2009 Location: socal iTrader: (1)	Nicely done writeup, the IS-F is definitely lexus pride and joy .
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12-02-2009, 03:24 AM	#16
BPMSport BimmerPost Supporting Vendor 3388 Rep 7,542 Posts Drives: Harrop M3 / F10 M5 / F82 M4 Join Date: Apr 2008 Location: SoCal iTrader: (9) Garage List 2000 BMW M5 [0.00] 1990 BMW 735i Turbo [0.00] 2008 BMW M3 [7.50] 2015 BMW M3 [0.00] 2015 BMW M5 [0.00]	No lifting with M5 or M6. You could make the shifts much smoother by lifting in less spirited driving situations. DCT has less of a bang and is slightly quicker due to the dual clutch. Our software makes the M5/M6 shift much better. __________________ -----\| Like us on Facebook \| Instagram \|\| Tuning Information \| Remote Coding \|----- ----Visit us at www.BPMSport.com - Emotion. Driven. \| Toll Free: (888) 557-5133----
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