What car did you the retrofit on? And was that just paddles and flash or were you actually changing boxes
6AT to DCT Converstion
- Thread starter doublespaces
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Well just pulled the trigger on a low mile dct, full shifter assembly and a mfactory lightweight flywheel. Looks like im doing the swap too. 
I'm going the M3 driveline route and have nearly everything except time to get it all done. I do have a 2.56 open diff if anyone is looking for one.
Okay. Is it possible to buy a random MSD81, lets say from a 330i, and Flash it to inaos Version? Is there something to Keep an eye on it?
First you'll need the new DME to be virginized / matched to your CAS and key. Then you'll need a custom MHD build from me to allow flashing of INA0S on a DME / car it wasn't intended for
I don't handle the first part, but I've done the second piece for a few DCT swap customers already, works wonderfully.
Hey guys,
last weekend I did the wiring for my dct swap. Iam a little bit confused because my old X6021, X6031, X6041 female connectors that came from the transmission has 2 rows with 4 big Pins. So my original male connector has it, too. The new connectors of the dct wire have 1 row 4 big Pins and one row with 8 small Pins like the wiring diagram.
Can anybody tell me if that is normal?
last weekend I did the wiring for my dct swap. Iam a little bit confused because my old X6021, X6031, X6041 female connectors that came from the transmission has 2 rows with 4 big Pins. So my original male connector has it, too. The new connectors of the dct wire have 1 row 4 big Pins and one row with 8 small Pins like the wiring diagram.
Can anybody tell me if that is normal?
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Wha
t if I buy a used z4is dct DME with CAS and keys would it work?First you'll need the new DME to be virginized / matched to your CAS and key. Then you'll need a custom MHD build from me to allow flashing of INA0S on a DME / car it wasn't intended for
Yes, its been done and you might want to read through some of what is involved in that here https://bmw.spoolstreet.com/threads...d-whilst-converting-to-m3-flash-and-gws.3011/
You are correct. The 6HP (namely the 2nd generation — 6PH21) is capable of 100% power-on overlapping shifts, depending on how it is calibrated/tuned. This can be taxing on the clutches at high loads/RPMs, however — and, thus, even xHP OTS calibrations progressively make torque reduction DME requests (at higher loads/RPMs) within the shift window (just like many DCTs are tuned to do in order to manage clutch heat/wear). Nonetheless, it is technically capable of full power-on shift overlapping (again, it all comes down to calibration) — and each clutch has it's own dedicated pressure regulation and can operate independently, with exceptional speed and precision (this is what separated this transmission from prior traditional automatic transmissions to that point). This power overlapping occurs routinely — when one can log and feel an uninterrupted, continuous flow of torque while transitioning from one ratio to the next under light to moderate loads, in "D Mode" , for example. We're not referring to perceived accelerative momentum being carried into the shifts (which is separate) — we're referring to uninterrupted torque delivery; which any Gen-2 6HP has the capacity to do, all dependent on calibration and the varied inputs being fed into said calibration (gear, load, RPM, and others and their interpolation).
As for the 200 ms and 100 ms references:
- 200 ms — you'll note that the context of the 200 ms reference is 'reaction time' (gear lever / paddle pull to shift actuation commencement).
- 100 ms — you'll find that the preceding context of the 100 ms reference is the shift time itself. While this is technically feasible (actually, for the X5M and X6M, it can occur within 80 ms), it becomes much more difficult to achieve this without compromising shift quality considerably — and can require thousands of hours of calibration to achieve both 80-100 ms shift times and seamlessness.
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That's interesting. I routinely see shifts of ~200 ms in logs, even at partial throttle. When I customize my xHP tune even more aggressively and under heavy loads and higher RPMs, I sometimes even see between 140-160 ms shift times. And, that's with more speed/aggressiveness left on the table in the xHP calibration.
Even lazy, partial throttle shifts are well under 400 ms, some closer to ~200 ms:
I think it all comes down to one's specific calibration and whether or not the TCU is seeing accurate DME torque values (which some JB4 setups or non-MHD flash tunes can muddy, resulting in slower shifts and with imprecise clutch engagement on upshifts). The ZF Gen-2 6HP is capable of a LOT. It really depends on how many hours of development one is willing to undergo to achieve both extremely fast shift speeds while also accounting for shift quality. These are often diametrically opposed, especially at the extreme end of one or the other — and it requires a LOT (and I mean a LOT) of calibration development to achieve both. But, it's possible — and there are literally thousands of tables in the TCU to manipulate to achieve that. For example, the 2010 X6 and 2010 X6M have the same ZF Gen-2 6HP transmission. However, their shift speeds and behavior could not be more different. The M division invested an untold number of development hours on the shift calibration of the X6M — resulting in shift speeds that occur within the window of a single cylinder firing event; for which ignition is cut to a single cylinder. Some automotive journalists actually thought the X6M was DCT-equipped (and they talk/write about it), before being informed otherwise by BMW. Conversely, the more 'pedestrian' X6 shifts more like a traditional automatic, even in Sport / Manual modes. Same transmission. Again, for the Gen-2 6HP (and with the 8HP), it's all about depth of calibration as opposed to capability.
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You have alot of insight on our trans so what's your take on pd clutches? Do you think I should be able to have full power shifts with the upgraded clutches and or be able to speed up shifts over a stock trans with xhp or do you think it will just increase my torque holding ability and not really allow faster shiftingThat's interesting. I routinely see shifts of ~200 ms in logs, even at partial throttle. When I customize my xHP tune even more aggressively and under heavy loads and higher RPMs, I sometimes even see between 140-160 ms shift times. And, that's with more speed/aggressiveness left on the table in the xHP calibration.
Even lazy, partial throttle shifts are well under 400 ms, some closer to ~200 ms:
I think it all comes down to one's specific calibration and whether or not the TCU is seeing accurate DME torque values (which some JB4 setups or non-MHD flash tunes can muddy, resulting in slower shifts and with imprecise clutch engagement on upshifts). The ZF Gen-2 6HP is capable of a LOT. It really depends on how many hours of development one is willing to undergo to achieve both extremely fast shift speeds while also accounting for shift quality. These are often diametrically opposed, especially at the extreme end of one or the other — and it requires a LOT (and I mean a LOT) of calibration development to achieve both. But, it's possible — and there are literally thousands of tables in the TCU to manipulate to achieve that. For example, the 2010 X6 and 2010 X6M have the same ZF Gen-2 6HP transmission. However, their shift speeds and behavior could not be more different. The M division invested an untold number of development hours on the shift calibration of the X6M — resulting in shift speeds that occur within the window of a single cylinder firing event; for which ignition is cut to a single cylinder. Some automotive journalists actually thought the X6M was DCT-equipped (and they talk/write about it), before being informed otherwise by BMW. Conversely, the more 'pedestrian' X6 shifts more like a traditional automatic, even in Sport / Manual modes. Same transmission. Again, for the Gen-2 6HP (and with the 8HP), it's all about depth of calibration as opposed to capability.
The primary benefit of the Propulsive Dynamics upgrade is to hold more torque at a given degree of clutch pressure. That being said, it is theoretically possible to reduce shift times with PD clutches, with an appropriate TCU tune — specifically, at torque levels that the stock clutches would begin to experience micro-slip. However, below these levels, the shift speeds should theoretically be the same, essentially (explained, a bit, in the next paragraph). Keep in mind, the Gen-2 6HP can snap off shifts that are so forceful that you are likely to start to damage axles and/or the drive shaft (and even transmission bearings). It can force a shift more suddenly and with greater force than with a manual transmission and popping the clutch (as with most automatics, it has multiple clutch disks per ratio, resulting in greater clutch surface area — primarily to help dissipate heat; but, with the added benefit of more bite and holding power, with an appropriate TCU tune). This (again, unlike other transmissions of its kind before it) is further aided by separate and independent pressure regulators for each clutch, each with a wide passage to generate almost any movement, slowly or near-instantaneously — and everything in-between. And, this is all carried out in closed loop and with the guidance of machine learning (the TCU monitors clutch slip, shift quality, shift speed, clutch temperatures for each of the clutches, and much much more, per shift event and over time... and adapts to all pertinent inputs), while using thousands of tables as its backbone. The limitation is literally one's comfort level and not the transmission's ability to snap off shifts — similar to a DCT. Beyond a certain shift speed, it becomes impossible to reconcile the rotational mass being exerted on the next ratio, within an extremely small time window... with the potential for very uncomfortable shifts that are more likely to upset the chassis or break traction than result in increased acceleration rates. Thankfully, xHP keeps users away from these tuning extremes (but, there is even more capability left on the table than what xHP allows in the app, left out for the obvious reasons of safety and reliability). Beyond a certain point, just as it is with a DCT, more is not more. As a matter of fact, some of the fastest M3s/M4s and 911 Turbos run their fastest times with their transmissions in their laziest settings, slurring through the ratios. Faster shifts don't matter as much when their is no torque interruption and clutch overlap, even with slower shifts — so long as the clutch slippage is not exercised to a point beyond which excessive heat is generated and clutch service life is significantly compromised.
Separately, to put it mildly, the Gen-2 6HP is a very complex unit. It will do things that no automatic transmission before it did, prior to its release. One of its many capabilities is the use of an adaptive shift strategy ZF calls ASIS — which allows the transmission to guarantee shift performance and feel, even as the clutches wear, regardless of load, clutch temperatures, and various other factors (within wide thresholds). Thus, in brief, the transmission will adapt to new clutches and eventually shift as it did before the clutches, all else being equal — but, with more holding capacity, simply due to the increased friction coefficient of the materials from which the PD clutches are made. This is where the TCU tune (or calibration) comes in — through which one can theoretically increase the ease with which a shift speed increase is achieved. A very loose analogy is when one upgrades their intercooler and/or DPs... with a stock tune, for example, the DME will simply target a certain output and, if it can achieve it with less boost than before the hardware upgrades (and/or with more aggressive timing), so be it — but, the output is essentially the same... unless it is tuned to take advantage of the hardware to achieve a higher output. The same can be said of the PD clutches and the TCU tune (oversimplified for the sake of analogy). At ~650 WTQ levels or below (generalization, however dependent on transmission health and other factors), the only palpable difference would be that the PD clutch equipped transmission might achieve ~160 ms shift times (for example) with greater ease than would be required with the original clutches. In other words, for a given shift speed, the calibration could be slightly less aggressive to achieve the same as what might have required a slightly more aggressive calibration with the original clutches.
All that said, to achieve extremely fast shift times with the Gen-2 6HP, my recommendation would be to have the DME in command of the tune, with the appropriate torque values being reported to the TCU (choosing the appropriate tune option in MHD or stock tune), and either cutomizing the shift speed or by having xHP develop a tune for you. If you do the above correctly, you'll find that you can achieve virtually any shift speed goal with or without the PD clutches (while finding a good balance between shift speed and shift quality). And, if you want to achieve the same crisp, rapid shift speeds at WTQ levels beyond ~650 WTQ (again, this may be a bit higher or lower, depending on TCU tune and transmission health) consistently and more reliably, this is the scenario in which PD clutches can be of benefit, with the appropriate calibration.
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I have inquired but haven't found anyone to do custom trans tune xhp said no longer does it. I assumed was cause of the customization module. Like you said though faster isn't best im more interested in less torque reduction . With dct and 6hp if axles and driveshaft are upgraded what's the next weak point ? The input or output shaft ? I know dct has clutch kits and I have the pd kit. I was told the converter is good for close to 1200nm which would be 885ft lb I don't know how accurate that is
