M3/M4 Preview of BMW M-DCT (new M3 gearbox)

[Zafiro]

Rear Wheel Drive, 7-speed, dual clutch transmission, wet

KEY BENEFITS

* Optimized efficiency
* Shifting without interruption of traction
* Excellent comfort
* Very quick and sportive shiftings possible

Max. Torque Capacity 600 Nm
Weight (dry) 79 kg


GETRAG Corporate Group - 7DCI600 TRANSMISSION

 

[martinbo]

How do you really know that this is the new M3 gearbox? Or is it an educated guess?

With 7 speeds and 600 Nm torque capacity, it's actually more closely suited to the C63 AMG...

I still think that the M3 will be a 6 speed box. Of course, I'm often wrong...

 

[Zafiro]

How do you really know that this is the new M3 gearbox? Or is it an educated guess?

With 7 speeds and 600 Nm torque capacity, it's actually more closely suited to the C63 AMG...

I still think that the M3 will be a 6 speed box. Of course, I'm often wrong...

They are talking about it on Rennteam and the M3 is getting a manual + DCT (DSG) in march/april 2008. I even know a guy having the M3 on order and he is waiting for the new gearbox , he also got a confirmation from bmw that a seqventiell gearbox is coming before the summer.

Wake up Martin , that M3 is getting DCT is old news are you really sincere that you didnt know this?

also SMG is being replaced with DCT(DSG) in all cars in the future.

 

[Zafiro]

I think this is a leaked document

 

[klier]

Thanks J_M. This is the gearbox I would want in my new M3.

 

[martinbo]

Wake up Martin , that M3 is getting DCT is old news are you really sincere that you didnt know this?

also SMG is being replaced with DCT(DSG) in all cars in the future.

Please man.

Read my post.

I ask how do you know that THIS (i.e. the 7DCI600 TRANSMISSION) is THE new M3 DCT gearbox? Everybody's talking about it... yes, there was information given sometime back as to the M3 getting a DCT gearbox. I know - really I do.

But, is this that you're showing us, the new gearbox?

a) How do we know that the next DCT gearbox for the M3 will be a seven speed? Why can't it be a six speed?

b) This gearbox is over-engineered by a capacity of 200 Nm for the application in the M3. I find this odd.

Hence my comment, that this transmission appears to be more applicable to the 7 speed, 600 Nm C63.

I'm not disputing that the M3 will get a new DCT transmission.

 

[vabboud]

maybe because this same gearbox with a bit of tweaking will be fitted to the V10 in the near future? it isn't over engineering, it is economies of scale
it is cheaper to design and manufacture a gearbox that will function on several models with different margins, then to build and design independent gearboxes
especially since these will be comparatively low volume boxes anyway

 

[DeDe]

I think this is a leaked document

It isn't IMO, as you can see there's no 7th gear ( - )

 

[vabboud]

no 7th gear but the place for one, so why leave a blan for something inexistent? there will be a 7 gear box later on

 

[Centurion]

b) This gearbox is over-engineered by a capacity of 200 Nm for the application in the M3. I find this odd.

Perhaps it is also going to be used in the future torque monster aka the rumored M5 with a turbo charged V10.

 

[warot]

Perhaps it is also going to be used in the future torque monster aka the rumored M5 with a turbo charged V10.

Bingo. THis gear box will be used across the range.

 

[bmer]

I think the link to that Getrag transmission has been posted at least two times in different threads. And so has that blurry picture of M3 Sedan specs... Nothing new really.

 

[vabboud]

but ocnfirmation nonetheless
if anything we can be sure that this box will be used with the uprated 3.0 turbo, and both M V8 and V10
since the torque rating allows

 

[martinbo]

I'd be surprised if we were to see one, ubiquitous gearbox across the entire range. The gear ratios and final drive ratios differ significantly between the M3 and the M5. (Duh - that's obvious one's a six-speed manual and the other's a 7 gear!)

BMW E92 M3
1st gear 2nd gear 3rd gear 4th gear 5th gear 6th gear
4.055:1, 2.369:1, 1.582:1, 1.192:1, 1.000:1, 0.872:1

BMW E60 M5
1st gear 2nd gear 3rd gear 4th gear 5th gear 6th gear 7th gear
3.990:1, 2.650:1, 1.810:1, 1.390:1, 1.160:1, 1.00:01, 0.830:1

I believe that the gearboxes for the M3 and bigger M cars will differ as the weight and torque capacities will be tailored to the cars' outputs.

Interestingly, see the current set of ratios for the 335i manual:

BMW E90 335i
1st gear 2nd gear 3rd gear 4th gear 5th gear 6th gear
4.055:1, 2.369:1, 1.582:1, 1.192:1, 1.000:1, 0.872:1

Identical to that of the M3.

So in all likelihood, the M3 and 335i will get the same DCT transmission and the M5 and M6 will get a similar but higher rated DCT transmission with different ratios I suspect. Time will tell of course...

On a final note, the increased number of gears allows for closer stacking of the gear ratios, the torque multiplying effect will essentially result in a much more vigourously accelerating M3 equipped with DCT than its manually shifted sibling. I'd be pretty peeved as an enthusiast and an owner of a manual gearbox M3 if the DCT model would be significantly faster all because of an extra gear.

Oh well, that's the price of progress I guess.

 

[Merc1]

Interesting. I'd say the extra capacity is indeed for future V10 applications, i.e. next generation M5/6.

M

 

[Zafiro]

Please man.

Read my post.

I ask how do you know that THIS (i.e. the 7DCI600 TRANSMISSION) is THE new M3 DCT gearbox? Everybody's talking about it... yes, there was information given sometime back as to the M3 getting a DCT gearbox. I know - really I do.

But, is this that you're showing us, the new gearbox?

a) How do we know that the next DCT gearbox for the M3 will be a seven speed? Why can't it be a six speed?

b) This gearbox is over-engineered by a capacity of 200 Nm for the application in the M3. I find this odd.

Hence my comment, that this transmission appears to be more applicable to the 7 speed, 600 Nm C63.

I'm not disputing that the M3 will get a new DCT transmission.

Ok sorry then if you got upset. My bad!

yes Im 100% sure the new gearbox is getting 7 gears.

If the link above is the exact gearbox for the M3 I cant say for 100% (only 90% ).

over-engineered? doest matter. Means more BMW's can use this gearbox in the future.


PS a M5 with SMG is faster than a manual M5. so yes I believe the M3 DCT is going to be faster than a manual M3.

 

[Sunny]

I'd be surprised if we were to see one, ubiquitous gearbox across the entire range. The gear ratios and final drive ratios differ significantly between the M3 and the M5. (Duh - that's obvious one's a six-speed manual and the other's a 7 gear!)

BMW E92 M3
1st gear 2nd gear 3rd gear 4th gear 5th gear 6th gear
4.055:1, 2.369:1, 1.582:1, 1.192:1, 1.000:1, 0.872:1

BMW E60 M5
1st gear 2nd gear 3rd gear 4th gear 5th gear 6th gear 7th gear
3.990:1, 2.650:1, 1.810:1, 1.390:1, 1.160:1, 1.00:01, 0.830:1

I believe that the gearboxes for the M3 and bigger M cars will differ as the weight and torque capacities will be tailored to the cars' outputs.

Interestingly, see the current set of ratios for the 335i manual:

BMW E90 335i
1st gear 2nd gear 3rd gear 4th gear 5th gear 6th gear
4.055:1, 2.369:1, 1.582:1, 1.192:1, 1.000:1, 0.872:1

Identical to that of the M3.

So in all likelihood, the M3 and 335i will get the same DCT transmission and the M5 and M6 will get a similar but higher rated DCT transmission with different ratios I suspect. Time will tell of course...

On a final note, the increased number of gears allows for closer stacking of the gear ratios, the torque multiplying effect will essentially result in a much more vigourously accelerating M3 equipped with DCT than its manually shifted sibling. I'd be pretty peeved as an enthusiast and an owner of a manual gearbox M3 if the DCT model would be significantly faster all because of an extra gear.

Oh well, that's the price of progress I guess.

The 6 speed transmission available in US spec M5 has pretty much the same ratios as the 6 speed in M3: 4.06/2.40/1.58/1.19/1.00/0.87. And I believe the 550 also uses the same transmission - it has the same ratios. So I don't think it is beyond the realm of possibility that the M5 and M3 will share a DCT.

 

[vedjo01]

Perhaps it is also going to be used in the future torque monster aka the rumored M5 with a turbo charged V10.

I wouldn´t bet on it because M5 allready has 520 Nm of torque so jump to 600 wouldn´t make an big step forward IMO..I mean,"if" updated M will get TT charging,torque should be atleast 650-700 Nm and that´s beynd limits of this gearbox to handle .