[mani009]

Starting to wonder how long these DCT transmissions will hold up to higher power levels, I guess its anyone's guess at this point. I am quite nervous to add a tune for now.

[skyintothesea]

SHIV, MY VP5 was shipped on Jan.12, it that the fireware fixed on my VP5?

[enrita]

Originally Posted by skyintothesea

SHIV, MY VP5 was shipped on Jan.12, it that the fireware fixed on my VP5?

most likely not since these are beta maps. just upload the newest maps and firmware when they are released.

[secretsquirrel]

Originally Posted by enrita

most likely not since these are beta maps. just upload the newest maps and firmware when they are released.

Exactly. I wish people would stop wasting Shivs time researching mundane things. We need him to spend his tine continuing development. It takes 30 seconds to update maps as long as you run the USB cable.

[k726]

The 7DCT tranny seems to be a bit weak. I'll have a post about it later this week. Let's hope it's not as weak as it's looking. Clutch pack is highly recommended though.

[Alext]

How many DCT tranmissions have failed so far? Stock or otherwise?

[mani009]

Originally Posted by k726

The 7DCT tranny seems to be a bit weak. I'll have a post about it later this week. Let's hope it's not as weak as it's looking. Clutch pack is highly recommended though.

Thats what I was worried about...should have went with a stick.

[Carrerra RS]

Originally Posted by shiv@vishnu

Hi guys
We've been working on this for a while. One of the problems we noticed when adding more torque to a 7DCT equipped car (either n54 or n55) is that the extra midrange torque can result in clutch slipping during full-throttle automatic downshifts. Depending on clutch/trans oil temp, this slippage can last a second or two where you notice the revs just float high without any vehicle acceleration. If it gets bad enough, an overtemp warning will appear on the dash sending the transmission in to a temporary safety mode were it wont even down/upshift for a few seconds.

So we added some logic that detects automatic downshifts and triggers a low boost mode until the clutch is fully engaged. Once engaged firmly, the Procede quickly transitions to full boost. Works like a charm. Downshifts are quick, slip-free and car takes off like a rocket.

(Similarly, the Procede will trigger a low power/boost mode if it detects transmission slippage in the middle of a pull.)

Below is demo video demo on our n55 DCT. Boost (0-20psi) is represented in the gas level gauge. Car is in regular D mode. For the first two pulls, all I did was stop on the gas and let the Procede+transmission control unit do the rest. On the third run, I tried to confuse the two by going 1/2 throttle to trigger a primary downshift and then quickly full throttle to trigger a secondary downshift before the primary downsnift was complete. Didn't miss a beat.

This feature has just been ported over to the n54 firmware but we still need to do some final testing. Anyone in the SF bay area have a n54 DCT car?

Has this issue been completely resolved based on your feedback?

[Mrbig]

new maps ? better now ?

[Imperator]

Originally Posted by shiv@vishnu

I don't there there is any known weakness in the 6AT transmission itself. If it aint broke, don't fix it!

Shiv,

You've probably spent more time behind the wheel of both transmissions than any of us, but should any of us Steptronic owners feel remorse over missing the DCT option in the 3-series?

I feel like I should have waited for the 335is, had I known the DCT would be available in 2011. I haven't driven a DCT car to see how it feels in comparison to the Steptronic, but If there are concerns with the clutches on the DCT with a tune, I'll feel a bit more content with the AT.

[FoShizzle]

Originally Posted by Imperator

Shiv,

You've probably spent more time behind the wheel of both transmissions than any of us, but should any of us Steptronic owners feel remorse over missing the DCT option in the 3-series?

I feel like I should have waited for the 335is, had I known the DCT would be available in 2011. I haven't driven a DCT car to see how it feels in comparison to the Steptronic, but If there are concerns with the clutches on the DCT with a tune, I'll feel a bit more content with the AT.

Actually, I probably have more seat time in both. I had a 6AT in my last 335i and now I have the DCT....

With the DCT it's a totally different car. (I know that not what you wanted to hear) For high HP modding, you may be better off with 6AT, but that remains to be proven. When I got my IS the DCT was a no charge upgrade option.

[Imperator]

Why is it export models got the DCT in the 335 in '09 and up while we were stuck with the Steptronic? I'm not complaining yet-- the steptronic is a great transmission, especially for mods, but I would probably have gone with the DCT if it were available.

[OpenFlash]

Honestly, the DCT transmission is very good but quite a bit more fragile than the 6AT. If you do silly things with it (or make it handle a lot of power), it will slip and/or overheat. Haven't seen one fail yet. Probably because the transmission induces a transmission limp before that happens. After some time in the 7DCT, getting back into a 6AT is a little disappointing. It's rougher, slushier and slower to shift. But you can take it to the drag strip and do hours of burn outs and it will be fine. Not the case with the 7DCT.

Shv

[D.B.S]

I hope all these developments lead to some headway into the 8 Speed X5's and 535's with the N55... Keep up the good work shiv... Counting my days until I can get some Procede love in my X5...

[techlogik]

I want DCT.....and an iS.

...and LSD...and...and....

Man, maybe I need to go back to my E46 M3 with S/C.....I miss her.

[FoShizzle]

Originally Posted by shiv@vishnu

Honestly, the DCT transmission is very good but quite a bit more fragile than the 6AT. If you do silly things with it (or make it handle a lot of power), it will slip and/or overheat. Haven't seen one fail yet. Probably because the transmission induces a transmission limp before that happens. After some time in the 7DCT, getting back into a 6AT is a little disappointing. It's rougher, slushier and slower to shift. But you can take it to the drag strip and do hours of burn outs and it will be fine. Not the case with the 7DCT.

Shv

Well put. Hey, do you have any n54 DCT (Z4 or 335) customers running a meth kit or dp's?

[Zaw]

Originally Posted by secretsquirrel

Exactly. I wish people would stop wasting Shivs time researching mundane things. We need him to spend his tine continuing development. It takes 30 seconds to update maps as long as you run the USB cable.

+1

[335iPSI]

Man, that's kind of disappointing --- I test drove a 7DCT 135 and man was that tranny wonderful --- hopefully someone will figure out it's just a clutch pressure issue or something fixable with software. I love my AT, but the quickness of the DCT was amazing.

[FoShizzle]

Originally Posted by 335iPSI

Man, that's kind of disappointing --- I test drove a 7DCT 135 and man was that tranny wonderful --- hopefully someone will figure out it's just a clutch pressure issue or something fixable with software. I love my AT, but the quickness of the DCT was amazing.

It really IS awesome. Don't be turned off by the temporary kinks.
Terry@BMS is updating firmware regularly. The latest is much improved and I have virtually no slippage. I'm sure Shiv@Vishnu is doing the same.