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      11-21-2008, 02:26 PM   #23
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Originally Posted by ruff View Post
Swamp and I go back a ways. I respect him and he respects me. We get along great and love heated banter and tough debates. An increased knowledge base and the enthusiastic passion we share for sports cars is the end result.
Give us a break. You made your debut here by trolling.
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      11-21-2008, 02:42 PM   #24
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Give us a break. You made your debut here by trolling.
Yes I did. My Lemond Zurich and I searching for a F1 like motor and an increase in knowledge base about the venerable M3. Boy was I lucky to run into you. M3 enthusiast to a core with an avalanche of preconception and but a sliver of credibility outside of an M3 powwow.
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      11-21-2008, 03:28 PM   #25
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Quote:
Originally Posted by ihyln View Post
Give us a break. You made your debut here by trolling.
I would not go quite that far. Some like to call ruff a troll. I really disagree. He is an enthusiast with very big soft spots for great cars including Ms and P cars. He loves to challenge the fan boys and status quo and is always on the skeptical side. We have had our fierce debates but his description of our relationship is accurate.

Dig a bit deeper if you bothered to keep up loosely with his posts and you want to see what really makes him tick!

Cheers.

Last edited by swamp2; 11-21-2008 at 04:02 PM.
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      11-21-2008, 04:01 PM   #26
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Quote:
Originally Posted by ruff View Post
Good to talk to you Swamp.

Not to say the C&D testing of DCT vs 6MT is scientifically valid but it is a real world test in less than perfect conditions, which is where real cars operate in the real world. You remember these results:

"But Is It Quicker?

After scouring the test results for some useful conclusion, the answer is “not really.” The M DCT car hit 60 mph in 4.3 seconds, cleared the quarter-mile in 12.7 at 113 mph, and achieved 150 mph in 26 seconds flat. Compare that to the six-speed manual’s numbers of 4.3, 12.8 at 113, and 24.3, respectively. If you zoom in even closer and look at each 10-mph increment, the two cars trade off which is quicker until 120 mph, when the manual starts pulling away."
Good point but the devil is in the details as they say.

1. 0-60 is a traction and uncertainty game not a good test of raw acceleration. I think most folks will consistently put down a better 0-60 with LC and the M-DCT as opposed to the 6MT.

2. Apples vs. apples. There is a belief that "testing" is always superior to simulation. The problem with this is that obtaining true apples to apples testing is very difficult. In this particular instance one effect surely present is break in. The 6MT was sure much more broken in in June compared to the M-DCT. We have seen the differences in the E46 (and just about any other car) that a good break in can make.

3. Single point of evidence. One test showing marginal difference surely does not make the case that "on average" the same findings will apply.

4. Time to speed is not the same as distance between speeds as Bruce always points out. Simulations of the MT vs. M-DCT show this. There are generally larger time gaps for contests from speed x to speed y than for times from 0-z mph.

More real world apples to apples testing is needed to see if these predicted advantages are realized in the real world.
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      11-21-2008, 04:31 PM   #27
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What I don't understand is how the MT is able to make up the speed it loses to the DCT at every shift, by the time it is necessary to shift again? Like between 300ft and 1000ft it seems to essentially be the same again. [~65-108mph range]


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      11-21-2008, 05:02 PM   #28
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Quote:
Originally Posted by swamp2 View Post
Thought you might know better by now. It seems you are the one who doesn't get it. CarTest will plot distance vs. speed and I have shown such plots in the past. Here are two ways to calculate this, one much less accuarate and one much more accurate.

1. d=rate x time. 130 mph x 0.6 seconds, which equals 7-8 car lengths. I know this is not exact; the relative point in the curve vs. shift points makes a large difference as well cars with drastically different shaped power curves can make this approximation worse, but in this case it is a pretty good approximation.
2. Graph from CarTest. Offset the curves to compensate for the fact that they represent a 0-X run. Distance required for DCT = ~1741 ft, MT =~1837 ft. This equates to 6-7 car lengths.

Anyone want to place a friendly wager on <5 car lengths or <0.4 seconds difference?

P.S. Reading from the graphs involves some inaccuracy but when actually using the software there is a cursor with a real time readout of the actual x and y values in proper units. This makes the error way less than what you would see trying to use paper or a ruler on the graph.
Apparently we're again talking apples and oranges here, or at least that's what seems to be the case.

When you said "The 60-130 figure will run about 0.6 seconds in favor or the DCT which is about 7-8 car lengths.", to me that means you think the auto will be ahead of the stick by seven or eight car lengths at that point.

Now you fire up that graph, which shows something entirely different.

What I get is that the auto will be ahead of the stick car by under two car lengths at the end of a 60-130 mph run. My logic is that when the auto gets to 130 mph six tenths of a second quicker than the manual, the manual is doing around 128 mph or so at that point, and it takes about six tenths of a second to make up that two mph. With both cars beginning the run with a zero difference in speed and ending with a two mph difference in speed, the average difference will be around one mph. Then assuming the cars are accelerating for something in the vicinity of 15 seconds to get from 60 to 130, that means a one mph difference for that period of time. With one mph equaling about 1.5 feet per second, that's 22.5 feet, which is a car and a half.

What I get from your chart plus explanation is that the stick car will take about 96 more feet down the road to get to 130 mph than the auto, which is of course an entirely different thing.

I'll take your proposed bet on "under four car lengths" between the cars at 130 mph. How about $100?

Bruce
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      11-21-2008, 06:09 PM   #29
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I made it a 4mph difference and that is why I said 3-4 car lengths. Though it does seem that you and I are on the same wavelength in our estimations of the gap.

I believe the devil is in the detail but you have to read the findings correctly.
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      11-21-2008, 07:00 PM   #30
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Quote:
Originally Posted by bruce.augenstein@comcast. View Post
Apparently we're again talking apples and oranges here, or at least that's what seems to be the case.

When you said "The 60-130 figure will run about 0.6 seconds in favor or the DCT which is about 7-8 car lengths.", to me that means you think the auto will be ahead of the stick by seven or eight car lengths at that point.

Now you fire up that graph, which shows something entirely different.

What I get is that the auto will be ahead of the stick car by under two car lengths at the end of a 60-130 mph run. My logic is that when the auto gets to 130 mph six tenths of a second quicker than the manual, the manual is doing around 128 mph or so at that point, and it takes about six tenths of a second to make up that two mph. With both cars beginning the run with a zero difference in speed and ending with a two mph difference in speed, the average difference will be around one mph. Then assuming the cars are accelerating for something in the vicinity of 15 seconds to get from 60 to 130, that means a one mph difference for that period of time. With one mph equaling about 1.5 feet per second, that's 22.5 feet, which is a car and a half.

What I get from your chart plus explanation is that the stick car will take about 96 more feet down the road to get to 130 mph than the auto, which is of course an entirely different thing.

I'll take your proposed bet on "under four car lengths" between the cars at 130 mph. How about $100?

Bruce
Well we are not far off but I was not using a proper metric on the car length and it shows up.

CarTest specifically records the simulation output for time from between any two speeds. Noticing I still had 420 hp (PS) instead of 414 in my inputs and after adjusting this the 60-130 times come out at:

6MT: 12.47 s
M-DCT: 11.84 s
delta = 0.63 s

The MT has a bit of difficulty getting the best time between begining in 2nd or begining in 3rd. 2nd has more torque to the ground but requires that pesky shift time penalty.

What is cool in CarTest is you can use the speed vs. distance and speed vs. time graphs together. The M-DCT will take about 1750 feet to go from 60-130. When it reaches 130 the 6MT car will have got up to 127.4 and will have covered 1709 feet making it 41 feet or 2.7 car lengths ahead. Rounding up I would put my best estimate at 3 car lengths. So given the interpolation accuracy you have with the graph I provided it shows your calculation as certainly correct in methodolgy. Foot: Your guess here was very solid as well IMO and I should have seen that my calculation was not at all correct - it was simply too large a figure.

I was calculating the difference in distance required for both to get to 130 mph which is not how you judge who is ahead of whom and by how much at a given speed . Thanks for helping me catch this silly error. I am happy that folks good guesstimates and the calculation is now quite consistent.

Note the 6 hp error makes very little difference here.
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      11-21-2008, 07:09 PM   #31
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Quote:
Originally Posted by ///Metak View Post
What I don't understand is how the MT is able to make up the speed it loses to the DCT at every shift, by the time it is necessary to shift again? Like between 300ft and 1000ft it seems to essentially be the same again. [~65-108mph range]


Attachment 205172
Pretty easy to see what is happening here and it is important. You are choosing a single gear for the 6MT but two gears for the M-DCT. Gear by gear the M-DCT has a distinct torque to the wheels advantage in 3rd through 6th (12-15%!) and in 1st and 2nd they are about a wash. Since the DCT gears are shorter for any given gear than in the MT the M-DCT will generally be in 2 gears and in this case covering about an equal distance in those different gears. It maintains the torque to the wheels advantage when the cars are in their same respective gear number (3rd in this case) but when the M-DCT goes to 4th the MT stays in 3rd accelerating harder than the M-DCT in 4th. This is typical with having the 1 extra gear. The gap closes and opens a bit based on what part of the run you are in. The disadvantage of shift times is plain to see as well (or said the same way the advantage of the really fast DCT shifts).
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      11-21-2008, 10:25 PM   #32
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Quote:
Originally Posted by swamp2 View Post
I would not go quite that far. Some like to call ruff a troll. I really disagree. He is an enthusiast with very big soft spots for great cars including Ms and P cars. He loves to challenge the fan boys and status quo and is always on the skeptical side. We have had our fierce debates but his description of our relationship is accurate.

Dig a bit deeper if you bothered to keep up loosely with his posts and you want to see what really makes him tick!

Cheers.
Sounds like you two really have something.
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      11-21-2008, 10:38 PM   #33
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Sounds like you two really have something.
No need for the sarcasm. If you hang out here long enough you will develop relationships; friends, enemies, those you respect and those you do not. Hopefully you'll even learn a thing or two from smart and interesting folks. I know I have.
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      11-21-2008, 11:51 PM   #34
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Quote:
Originally Posted by swamp2 View Post
No need for the sarcasm. If you hang out here long enough you will develop relationships; friends, enemies, those you respect and those you do not. Hopefully you'll even learn a thing or two from smart and interesting folks. I know I have.
+1

I know I have.
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      11-22-2008, 04:32 AM   #35
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Swamp,

I understood where your mistake was but couldn't put it into the right words on how to explain it. I estimated 4mph but as you had the hard data you found this to be in fact only 2.7mph of a difference which equates to 2.7 car lengths and that IS when the manual driver makes the shifts perfectly, so my estimates of 3~4 car lengths is probably spot on as an average.

I know Ruff quoted a test result which found the manual to be quicker after 120mph but I still believe this M-DCT car was not performing at it's best, the different gears and the shifts should let the dual clutch car mantain it's small margin.
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      11-22-2008, 01:36 PM   #36
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Guys.....argue all you want that the 6MT is "better" (in pure subjective terms)....when it comes to all out performance the ONLY advantage the 6MT has is the lower weight.... 1st and 2nd gear are about the same in both transmissions..... other than launch control it would be pretty even....BUT once in third gear the DCT will pull ahead.....since 3rd goes about 99mph in the DCT vs 111 in the 6MT....4th is even worse for the 6MT...148mph in the 6MT and only 125mph or so for the DCT..... & I didn't even factor the faster shifts in the DCT



If the DCT skipped 4th gear.....then the ratios would be pretty similar....
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      11-22-2008, 10:40 PM   #37
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Just yesterday I caught swamp standing on his soap box crowing the "all is well in DCT-land" on one thread, and than explaining how he "had his service manager out for a ride so that he could show him a DCT update problem" THAT THE VERY SAME DAY!

How many times does a DCT have to be back to the dealer with problems before you can have it replaced with a MT under the LEMON LAW?
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      11-22-2008, 11:13 PM   #38
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Just yesterday I caught swamp standing on his soap box crowing the "all is well in DCT-land" on one thread, and than explaining how he "had his service manager out for a ride so that he could show him a DCT update problem" THAT THE VERY SAME DAY!

How many times does a DCT have to be back to the dealer with problems before you can have it replaced with a MT under the LEMON LAW?
For one this is totally off topic and for two I have been standing up on my soap box about DCT since well before we knew any details about the unit and well before you even joined this forum. What part of my opinion can't you understand? Let me be very explicit for your benefit.

1. The transmission with the OEM software was truly brilliant, nearly perfect on the street but with a couple rare but significant glitches on the track. It has always got a 9.5/10 rating from me.
2. The first software update fixed all of the known glitches that occurred when driving at 9/10ths-10/10ths, improved the S mode shift delay but also created another new low speed delay type of problem. It is annoying but you can pretty easily slightly alter your driving style to completely avoid it. I did point this out to my service advisor because BMW has already shown to be very responsive to the need for revised DCT software and when folks complain they will do so in the future as well.

9.5/10 rating then, 9.5/10 now, and I think most owners feel about the same. I'd never have the car with a MT.

Got it champ?
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      11-22-2008, 11:56 PM   #39
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No, champ doesn't get it.

The forum is over run with DCT threads... ALL of them complaining about the shortcomings of a new high tech transmission that works wonderfully on paper and in the hypothetical world but has more issues than the United Nations on real paved roads.

You may not want to admit it, but there are very real problems with DCT, just as there was with SMG. STALLING, LURCHING, JERKING, DELAYS, RECALLS... The only way I would consider a DCT is if I was a left legged amputee, and it even rhymes!
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      11-23-2008, 05:30 AM   #40
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I can tell you that on a whole DCT works very well. The only problem I notice is the lag when braking into second gear and then starting to accelerate.

P.S.
One thing I would like to add is that DSG in the GTI never had any of these problems, so maybe it's the way the software has been wrote more so than the technology.
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      11-23-2008, 06:39 AM   #41
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No, champ doesn't get it.

The forum is over run with DCT threads... ALL of them complaining about the shortcomings of a new high tech transmission that works wonderfully on paper and in the hypothetical world but has more issues than the United Nations on real paved roads.

You may not want to admit it, but there are very real problems with DCT, just as there was with SMG. STALLING, LURCHING, JERKING, DELAYS, RECALLS... The only way I would consider a DCT is if I was a left legged amputee, and it even rhymes!
If you don't want it BMW gave you the option to get a manual, I don't see your problem.

Fact is the DCT is faster and shifts faster than you ever could. Not to mention it a superior all around gear box. The technology is amazng, BMW just needs to refine the software. It isn't physcal limtations creating these errors.
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      11-23-2008, 10:03 AM   #42
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My only question about DCT (cause I haven't gotten to play with one) is how long does it take from the time you pull the paddle until the shift starts to happen? Why does no one take that into account when comparing shift times between DCT and MT? I'm sure DCT is faster, but I know my MT starts shifting gears exactly at the moment I tell it too.
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      11-23-2008, 11:28 AM   #43
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I would think that the DCT would be quicker than the graph would indicate, says a a lot for the efficeincy of the 6MT drivetrain, but the one thing is you have to execute perfect shifts every time, always room for human error, where as in the DCT there is none.
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      11-23-2008, 12:06 PM   #44
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Quote:
Originally Posted by NewM3driver View Post
No, champ doesn't get it.

The forum is over run with DCT threads... ALL of them complaining about the shortcomings of a new high tech transmission that works wonderfully on paper and in the hypothetical world but has more issues than the United Nations on real paved roads.

You may not want to admit it, but there are very real problems with DCT, just as there was with SMG. STALLING, LURCHING, JERKING, DELAYS, RECALLS... The only way I would consider a DCT is if I was a left legged amputee, and it even rhymes!
Lewis Hamilton uses an automated manual,similar to a smg (no clutch pedal) and He's not a left legged amputee.
I'm not a big fan of i-drive and the likes but technologies that improve performance can't be a bad thing.I have a MT but wouldn't mind a DCT,I'm sure BMW will have all the bugs worked out.
I find it rather amusing when some members here think they're special or hardcore because they have a MT.HA
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