DCT Swap + S54

[Martyn]

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

[Casa de Mesa]

Thank you Martyn ! That's a bigger difference than I would have expected.

[Martyn]

Gear	Stock M3	Long Ratio	Short Ratio
1	4.23	4.81	4.78
2	2.53	2.59	3.056
3	1.67	1.7	2.153
4	1.23	1.28	1.678
5	1	1	1.39
6	0.83	0.84	1.203
7		0.67	1

[Casa de Mesa]

First Gen DCT Short ratio as found in the E9x 335i, E9x M3, and E8x 135i / Z4 35i.
Second Gen DCT Long ratio as found in the F8x M2/M3/M4 and F10 M5.

Out of curiosity, do you know what those ratios are?

[Martyn]

First Gen DCT Short ratio as found in the E9x 335i, E9x M3, and E8x 135i / Z4 35i.
Second Gen DCT Long ratio as found in the F8x M2/M3/M4 and F10 M5.

[Cubieman]

A few in europe, in fact, even a honda s2000 k24 with dct box in Spain, a e36 m50 i think, with dct in germany...

These DCT swaps are indeed becoming more popular, on the "All Girls Garge" TV show they used an adapter that allowed usage of a DCT (from an F80 M3) and matted it to a 2jz Supra.

How many iterations of the DCT's are there at this point? I am not well versed at all with these.

[K-Dawg]

Concur. The only advantage of the DCT over the SMG is being able to shift in high G corner. The DCT doesnt upset the car as much as SMG.

I would think more, closer gear ratios is an advantage. The DCT gives you 5 or 6 usable track gears instead of 3 or 4. With DCT you should be able to spend more time in the powerband.

[Icecream]

It only suffers for the lazy who drive it like an automatic. SMG was perfectly smooth in my decade of ownership with it.

Absolutely pointless swap, but if you’re bored in a locked down country, I get it.

Right, drive it with the same attention as a traditional 6speed and it’s just as smooth (if you can drive stick well),

[Casa de Mesa]

Absolutely, that is the current alternative. The Drenth setup allows for a bunch of different setup options as well. Candidly, I am not as familiar with what the DCT conversion fully involves at this point. My favorite track setup for our car is in the video below (Mike Skeen-VIR w/ Drenth). It's humbling to watch him destroy my home course. The interior setup is in line with my final build plans. Clean. Functional.

https://www.youtube.com/watch?v=AIXt...nnel=MikeSkeen

I have thousands of miles at that track in the various configurations, but mostly VIR Full. The gearing in that car is almost perfect for VIR Full: 2nd gear coming out of the tight corners and the car hits max RPM just at the end of the back straight.

Great vid, good stuff.

Casa

[Fresh1179]

If it's strictly a track car, have you looked into putting in a Drenth gearbox?

Absolutely, that is the current alternative. The Drenth setup allows for a bunch of different setup options as well. Candidly, I am not as familiar with what the DCT conversion fully involves at this point. My favorite track setup for our car is in the video below (Mike Skeen-VIR w/ Drenth). It's humbling to watch him destroy my home course. The interior setup is in line with my final build plans. Clean. Functional.

https://www.youtube.com/watch?v=AIXt0ZV5cDw&ab_channel=MikeSkeen

[bjz!]

A few in europe, in fact, even a honda s2000 k24 with dct box in Spain, a e36 m50 i think, with dct in germany...

[Rkymtnrider]

It only suffers for the lazy who drive it like an automatic. SMG was perfectly smooth in my decade of ownership with it.

Absolutely pointless swap, but if you’re bored in a locked down country, I get it.

I totally agree. My m is my 5th vehicle and 1st w/o a 3rd pedal. I’ve always driven it like a manual and responds the same, just faster.

[Chas3n]

Pretty cool effort.

Amusingly, I feel like SMG isn't particularly worse than DCT on track-- it's on the street where SMG suffers in comparison.

It only suffers for the lazy who drive it like an automatic. SMG was perfectly smooth in my decade of ownership with it.

Absolutely pointless swap, but if you’re bored in a locked down country, I get it.

[shibui]

This is kind of the ultimate goal for my build. There is a thread on M3Cutters where the guy went through the build process and the parts he used/removed and exchanged. I'll edit my post when I find it here in a moment. I just love the ingenuity.

If it's strictly a track car, have you looked into putting in a Drenth gearbox?

[chalaka]

waiting for this mod to become popular and "easier" for normal DIYers to perform :P

all those wiring, coding process look extremely difficult and challenging to me .. haha ..

hate to go through all those tedious procedures to find out it's not working right .. or f up the transmission board due to bad soldering .. (@@)