DCT Swap + S54

[S14]

as and SMG owner, I'd love to do the DCT swap!

[Casa de Mesa]

This was my car on the long ratio box with a 4.10 rear end.

I didn't realize you had done this before. Sick! Did you do the conversion yourself? Do you have any other details?

I'm 6MT so probably not doing this swap anytime soon (ever), but the technical feat for the pioneers who decided to make this work without a kit available or manual to go by... call me impressed.

[George Hill]

If you decide to attempt this, don't bother with the HTG junk, it's utter rubbish! Been there, done that lol.

This is the comment I came here for, haha.


What about a ZF8 speed auto swap?

[bigjae46]

This is the comment I came here for, haha.


What about a ZF8 speed auto swap?

Never thought I would see the day where there is an auto E46 M3...lol

I love my E90 M3 DCT. Its constant power with a quick jerk on the upshifts.

[George Hill]

Never thought I would see the day where there is an auto E46 M3...lol

I love my E90 M3 DCT. Its constant power with a quick jerk on the upshifts.

To be fair that is an Auto S54 touring, lol.

But really I think there is a decent market for these (same as what the DCT retrofit option was SUPPOSED to be) for people who don't want a clutch pedal but also don't want a SMG.

[Slideways]

It appears that tuning seamless downshifts for the DCT swap is no small feat. Almost every video I have seen with these DCT swaps has some issue changing gear smoothly.

[lastMleft]

The DCT is great on the s65, looks like it works well on the s54....wish I could drive it lol....

[Arith2]

It appears that tuning seamless downshifts for the DCT swap is no small feat. Almost every video I have seen with these DCT swaps has some issue changing gear smoothly.

What are some of the factors that make it difficult?

[George Hill]

What are some of the factors that make it difficult?

The factors are HTG. But really for the most part you have 3x options for DCT controllers: MaxxECU, DKGECU and HTG Tuning. HTG is the most prevalent and drivability seems to be 100% dependent on the end users definition of drivable. Some people say they are great, some people through them in the trash (metaphorically speaking) like Martyn.

[chalaka]

would love to read/hear more updates from this DCT swap experience journey~

[bigjae46]

It appears that tuning seamless downshifts for the DCT swap is no small feat. Almost every video I have seen with these DCT swaps has some issue changing gear smoothly.

I know that changing the gear ratios on the E9X M3 can sometimes screw up the shifting. Two popular gearsets were 3.45 and the 3.62. I haven't heard of anyone having an issue with the 3.45. Have heard of issues with the 3.62. Apparently there is software for the OE transmission control unit that fixes shifting in both manual and auto modes.

I want to put a 3.62 in my E90 M3...someday...when I get off my lazy ass.

From a couple of short rides on G80 M3s...the auto trans in the G8X is every bit as fast on the shifts as my E90 M3 DCT. The auto feels like a DCT. I have to wonder how much more does it weigh than a DCT?

[usdmej]

What about a ZF8 speed auto swap?

those ZF boxes > any DCT out there

[George Hill]

I'd bet my auto setup weights in about 220#, it is not light by any means.

Here are some laps at CoTA with my ZF8/S54 touring. Still some transmission tuning left to do but you can hear the shifts. I was also playing around with lifting on the shifts to see if that affected anything as well (trans temps namely).

https://youtu.be/HS-9eHkXva0?t=171

[acb.m3]

Old thread bump - Anyone done the swap in 2023 or 2024?

[George Hill]

There is still no fully integrated transmission controller for the DCT using an MSS54 DME. CANTCU is getting close. HTG is essentially vaporized. The only other option is converting the engine to run on a MaxxECU and using their DCT protocol (or any other number of standalone ECUs and a CANTCU).