[ZPrime]

I searched through this forum a few times but wasn't really turning anything up.

In the VW world that I'm familiar with (Golf R / R32), the DSG is actually far more capable of holding torque past the rated limit than a 6MT is. 6MT you can get there by replacing pressure plate & clutch, big pain in the ass and relatively costly parts, and you're going to build up a giant left thigh working the clutch.

The DQ250 (rated for 250 Nm of torque) is capable of holding north of 600 N-m (i originally had the wrong unit here, sorry) of torque with just a software flash. However, in order to actually make any power beyond stock, you generally have to flash the transmission because otherwise it will send messages back to the ECU and cut power.

In the BMW world, what happens with the DCT is given more power than stock? Do you need to flash these as well, or do they behave more like a 6MT and just take whatever they're given? Will the M-DCT hold more torque than the 6MT with a flash? Or does it make more sense to go 6MT if you have bigger power plans?

[mrcheezle19]

The DCT will need dodson clutches around the low 600whp mark to keep putting the power down. Seen a manual car making making close to 700whp with no issues. I'd imagine an alternative material clutch would be in the mod list if you are looking for that power level. At any rate it seems like both transmissions seem to hold power well and not break. Proper driving is always a key component of that though.

[Benef1cient]

I think Robin_NL said that MT can handle up to 550-600 Nm and DCT up to 700 Nm - heard on another forum apparently from guys who were modding their cars heavily. I also see all tuners (JP Performance, Hamann, Manhart etc.) take DCT also probably due to this fact.
I think it's reasonable to take DCT if you plan to mod it above that 550 Nm. Flash for the trans is not really needed, you can flash it with M4 GTS soft if you want but there are no significant changes from what I've read.

One comment about the DQ250 (which I currently use in my GTI) it can hold 400Nm without slipping the clutch not 250. Overall it's the same case for GTI as in M2 - guys upping the HP & TQ on MT cars need to put beefier clutch while DSG can handle it quite ok (although with some recommended software tweak to limit Nm on 1-2 gears to enable smooth start from standstill).
Maybe it's due to the fact that there are in fact two clutches inside the DKG in both cases, so they can handle more?

[David1]

No need to flash the BMW DCT for mild tuning.

[ZPrime]

Originally Posted by Benef1cient

One comment about the DQ250 (which I currently use in my GTI) it can hold 400Nm without slipping the clutch not 250. Overall it's the same case for GTI as in M2 - guys upping the HP & TQ on MT cars need to put beefier clutch while DSG can handle it quite ok (although with some recommended software tweak to limit Nm on 1-2 gears to enable smooth start from standstill).
Maybe it's due to the fact that there are in fact two clutches inside the DKG in both cases, so they can handle more?

Maybe in Europe the tuners just aren't as good... I am friends with one of the owners of United Motorsport, I know for a fact they have cars over 400 ft-lbs on stock clutches with just software. That's about 540 Nm... They claim "good for 650 N-m" on their stage 2 DSG flash (no clutches). With uprated clutches on stage 3, they say 800+ N-m.

[rusky]

Any word on how the manual transmission holds up with with minor/intermediate tuning? The GS6-45BZ unit is rated for 470nm which is basically what the car puts out stock. Can the clutch/pressure plate be upgrade to boost that value or is it directly related to the gearbox internals?

[mrcheezle19]

Several M3/M4 are in the mid 600s with manuals without issue. Go read through their engine/tuning section.