DCT software differences between E and F chassis

doublespaces

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I've heard the TCU software is much better in the N55/S55 in terms of power handling and potentially other things, does anyone know what the differences are and/or what would be required to communicate with that TCU software instead?
 

aus335iguy

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I’ve heard the same, need to be careful as some boxes like the one in the M2 have different gear ratios. That could be one of the reasons why they might be stronger. M2/m4 uses longer gearbox gearing (ratios closer to 1:1) and a shorter diff.
 

doublespaces

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My DCT transmission is from a 2012 135i, then it needs programmed to something the 335is had, which is some other ZUB number. I suppose my question, is in what way is that communication different, and how could we get our DME to speak to the same TCU software? @jyamona

I'm starting to wonder, what is the most power someone is making on an N54 DCT?
 

Sbrach

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The software versions are interchangeable, well for the E series at least. I am running 135is (N55) software on my non-is 135i that is also N55 but plenty of people run the same ZB on 335is which is N54 to get the lower Launch Control RPM.
 

doublespaces

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The software versions are interchangeable, well for the E series at least. I am running 135is (N55) software on my non-is 135i that is also N55 but plenty of people run the same ZB on 335is which is N54 to get the lower Launch Control RPM.

Interesting. Now that you mention it, I have heard about the 1 series software for the launch RPM. So, lets say the software that is on the M5 making 1000whp. What software is that and will it work with an N54?
 

doublespaces

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I've updated the thread title to be F vs E rather than N54 vs N55/S55 as I think that is where the differences are which I'm referring to.
 

Sbrach

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I think it’s really gs7d36sg vs gs7d36bg.

They both look to use the same mexhatronics unit wth different software. The gears are supposedly hardened in the bg and they have a different park mechanism. Possibly different gearing.

I’m optimistic someone will get an Damos and find a flash exploit. The work seems like it will carry over to pretty much every BMW with a DCT.
 

aus335iguy

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Yep the gearing is significantly different sg vs bg and so the software won’t carry across. 135 and 335 software can because the gearing was the same but not sure about new variants
 

doublespaces

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@BMWJunkie told me(see a trend here?) that F chassis cars use a different communication system and don't have a JBE, Board Net 2010. I've seen this on my combox while doing the retrofit, BN2000 for example on E chassis cars.
 

Blue335is

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I've always found it interesting that people claim that one is stronger than another when we have almost no records of the dcts breaking. How can we claim one is stronger than the other when I dont know of a single case of a dct equipped n54 having an actual transmission failure. Has anyone else heard of or seen a case of this?
 

doublespaces

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N54? Not off the top of my head. I'm sure they have failed but perhaps not due to excessive power but rather incorrect tuning, defects or abuse. I think the main reason, is that nobody has pushed one that hard from an N54.
 

Sbrach

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Yep the gearing is significantly different sg vs bg and so the software won’t carry across. 135 and 335 software can because the gearing was the same but not sure about new variants

If the software is unlocked then gearing changes can be accounted for. The point being that the work to unlock tuning options for one DCT will likely carry over to the other DCT variants and that large of a market should make it worth doing.
 

Blue335is

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N54? Not off the top of my head. I'm sure they have failed but perhaps not due to excessive power but rather incorrect tuning, defects or abuse. I think the main reason, is that nobody has pushed one that hard from an N54.

I'e only ever seen clutch pack failures.
 

aus335iguy

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The point being that the work to unlock tuning options for one DCT will likely carry over to the other DCT variants and that large of a market should make it worth doing.

We all think so but were all wrong. Apart from the (expensive for consumer use) Magic PRO2 TCU manager that @dyezak pointed out no one has managed it
 

dyezak

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Read a single instance on 2nd gear teeth stripping off on a DCT. They sent the trans to Dodson for them to fix. Maybe doublespaces can get us the low down on it.
 

doublespaces

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Read a single instance on 2nd gear teeth stripping off on a DCT. They sent the trans to Dodson for them to fix. Maybe doublespaces can get us the low down on it.
A little birdie told me they have a custom input shaft and gears. So I guess this may not really matter depending on your pay grade.
 
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