Which is quicker, 6MT or DCT?

[footie]

I know it the sort of debate which could spark a heated argument but I got to drive an M3 manual this morning which was totally run in and though in gear it felt every bit as quick as my DCT car the gear shifts are quite slow, slower in fact than my S5's were.

I am dieing to see that race because I think by judgement was/is correct and the DCT will have a narrow victory, solely from the shifts themselves.

[M-Maika]

Originally Posted by footie

I know it the sort of debate which could spark a heated argument but I got to drive an M3 manual this morning which was totally run in and though in gear it felt every bit as quick as my DCT car the gear shifts are quite slow, slower in fact than my S5's were.

I am dieing to see that race because I think by judgement was/is correct and the DCT will have a narrow victory, solely from the shifts themselves.

According to BMW, DCT is faster.

Best Regrds, Maika

[Deda]

dct is faster.

[MDCTFTW]

I think it would be a decent sized victory in the quarter. Visible.

[!Xoible]

Originally Posted by footie

I know it the sort of debate which could spark a heated argument but I got to drive an M3 manual this morning which was totally run in and though in gear it felt every bit as quick as my DCT car the gear shifts are quite slow, slower in fact than my S5's were.

I am dieing to see that race because I think by judgement was/is correct and the DCT will have a narrow victory, solely from the shifts themselves.

footie u been on here for along time to see all the threads about this. i like ur posts and i respect them but seeing this thread i cannot but ask you: ARE YOU FUCKING NUTS?????

[oneginee]

Insecurity of not having chosen the 6MT and lacking the fun of manual clutch engagements ?
The 6MT is the quickest for driver's satisfaction my opinion of course.

The DCT did not receive the unreserved approval of the car press that it could have: downshifting lags in the DCT (maybe not with the sw update or 09 DCT ? ).

The higher gear ratios in the 6MT are reducing the gap between human shifting/clutching versus machine shifting/double clutching

But here is a test results comparison from fastestlaps showing the manual is faster from 0-160 km/h and quicker at the quarter mile time. And yeah the DCT is faster from 0-100km/h. But to me these results do not matter that much what counts is the smile and undescriptible satisfaction I get from releasing that clutch pedal and intimately feeling the tranfer of power.

You can hate me now DCT guys


Contidrom Track
Track M3 (E92) M3 (E92) DKG
1:35.41 1:35.11

Specs
Discipline M3 (E92) M3 (E92) DKG
Max speed 155 m/h (250 km/h) 155 m/h (250 (restricted) km/h)
0-100 km/h acceleration 4.6 4.3
0-160 km/h acceleration 9.4 9.7
0-200 km/h acceleration 15.2 15.2
0-300 km/h acceleration - -
Quarter mile time 12.5 @ 114.8mph 12.6 sec @ 113.2 mph
Power/weight ratio 0.19 0.19

Summary
Discipline M3 (E92) M3 (E92) DKG
Track Performance 0 points 2 points
Straight line speed 237 points 235 points
Total 237 237

The Answer
Both cars are equally fast.

[icemang17]

The DCT does shift faster & has the benefit of an extra gear that should help around 80-100mph....but is about 45lbs heavier.....

In theory the DCT should win a drag race......

[McLuVan]

speed
dct>6mt
fun
6mt>dct
it all depends on what you bought the car for
if you buy it for fun get the 6mt
if you buy it for speed then the dct is better
for instance the loaded m3 is a smg

so I'm sure the dtc is faster
but I'll ever buy a dtc

becauseeeeeeeeee
1. can't afford it
2. I want a 6mt

[masmole]

If you were a highly skilled race car driver consistently adept at heel-toe shifting and are able to extract every last second off a lap time from a given car, then I'd say the advantages of DCT around a track are minimized, if not neutralized.

The truth of the matter is that the majority of us aren't, and that includes even the few who have considerable track experience. For the average M3 track-day enthusiast, the benefits of DCT becomes more significant. It allows you to have more consistent laps and to focus more on your line and braking by greatly reducing the possibility of botching a downshift (although it's still possible to forget to downshift entirely). Some may say that this takes away from some of the involvement in driving around the track, but in my humble opinion, I believe it opens up new avenues towards honing other aspects of the average enthusiast's driving skills. After all, I doubt any of us are actually wheel-to-wheel racing against other cars in our $60k+ daily drivers. And after all, there's a reason why the modern F1 car are quipped with sequential paddle-shifters minus a foot-operated clutch pedal (yes I know there's a clutch lever on the steering wheel).

Lastly, M-DCT FTMFW!

[torredresen]

Yeps,on the record the DCT is faster:
6MT : 0-100 km/h : 5.3
DCT : 0-100 km/h : 5.1

It's just a question of preference, one isnt better than the other
DCTFTW joke

[swamp2]

A few key issues have been missed (or minimized)

1. The DCTs advantage is BOTH from fast shifts but also the gear ratios and close spacing enabling more engine operation time near peak power.
2. oneginee has compiled a nice list of comparisons above but we can not forget the effects of the various minor DCT software bugs (many already verified as corrected), especially the two that mostly only show up while at the track.
3. Some of the races on m5board.com have shown a strong advantage for DCT
4. But dynos are not very accurate when comparing how close these cars actually are.
5. Consistency is as important in launching/dragging as track work (as masmole pointed out). Here the clear advantage goes to DCT.
6. In most all cases, street, strip, track, etc it will mostly be a drivers race between the cars and drivers.

Lastly as a long time MT owner driver I strongly disagree than for fun MT>DCT.

And really lastly... footie:

[footie]

///Mantis,

I hope I'm not nuts but I do have a screw lose.

Swamp,

In my opinion it's not a report. Previously the other thread was a debate with no prior knowledge or experience of DCT.

Now we all are fully aware of DCT with it's plus and minus points. Like I said I got the chance to try both back to back and my opinion based on a hunch was that all of that small gain was coming from the gear change, but without hard data I can't say how much of a benefit the shifts were making.

One thing I noticed was that I found it easier to pick my shift points with DCT and I know I was struggling to complete the shift in less than 0.4s in the manual. Of course more experience in the manual would possibly improve this but I know I couldn't get close to the DCT in this.

Whether the manual is quicker as the speed shifts over the 100mph mark I don't know but up to then I felt the advantage was with the DCT.

Also this debate/discussion is not on which is the most involving because we all know which one that is but purely which is quicker in acceleration.

P.S.
I also feel that non-launch control yields the quickest acceleration.

[Sticky]

DCT is significantly faster in the 1/4, tighter gearing, faster shifts, ridiculous launch, no shift at the end (manual 3rd ends at 113).

[JPH]

I am pretty old school on this. Clearly the DCT is faster for 9.9 out of 10 drivers but, learning to upshift appropriately (at right RPM) and downshift/match RPM is a lot of fun and, in the end, makes one a better overall driver. Before long, there will be many young driving enthusiasts who have never drive an MT. I think they will lack an extra driving sense that those who have driven an MT will have. It may not make one much (if any) faster to have that experience but, it would make one a more well rounded driver.

[swamp2]

Originally Posted by Laszlo

How can the DCT be faster when every lap test has shown it failing big time and laps having to be completed in "automatic" mode? Making the M3 "slowest" in its class?

The DCT IMO has ruined all benchmark tests (that'll live on the net forever) because of its lag and downshifting problems.

They should have been done the lap tests with both a DCT and 6MT and published the fastest number...

But instead, they've only done DCT which ruined the M3 reputation.

Just to be clear no lag issues whether you are talking about the time between paddle pull and begining of clutch operations nor the low throttle sensitivity on slow to medium starts affects track performance nor times.

Of course, I do agree they screwed things up and that the bad numbers will live on as "the" numbers for the M-DCT. Hopefully someone from a rag, maybe someone reading here, will re-test.

[White Shark]

I might be wrong, but it sounds like some members have never driven M3 DCT or Audi/VW DSG before...

[TLud]

How is this really a debate still? Don't we all already know that DCT accelerates faster thanks to the speed of the shifting (and possibly also the slightly different gearing)? I'm not trying to be a smarta$$, I just thought that this was settled?

Around a track, I would think the difference would be extremely minimal for a relatively experienced driver, even now that the downshifting issue with DCT has been fixed. Many of the shifts on a track are not under acceleration, so the speed of the shifts isn't really a factor.