2012 DCT

[Donbona]

Does anyone know if there would be a difference between a 2008 DCT box and a 2012 version??

[ChrisK]

As far as I know, nothing but the software (if the car hasn't been updated)

[Donbona]

Ive had the updates.... just checking.... having some issues with my car but nobody seems to be able to find out why

[phrozen06]

What are the issues?

[Donbona]

Originally Posted by phrozen06

What are the issues?

Ok... im not sure wether its the DCT box or throttle actuators.... but here goes....

When I am accellerating my car is fine but when I am slowing down to approach lets say a bend, I blip down to 2nd gear or 3rd.... take the bend than put my foot on the gas and get absolutely nothing... when connecting the computer to the car it showed that the throttles actuators are not opening at this point....... but they open fine when you are going up gears.
Does that make sense??

[phrozen06]

Originally Posted by Donbona

Ok... im not sure wether its the DCT box or throttle actuators.... but here goes....

When I am accellerating my car is fine but when I am slowing down to approach lets say a bend, I blip down to 2nd gear or 3rd.... take the bend than put my foot on the gas and get absolutely nothing... when connecting the computer to the car it showed that the throttles actuators are not opening at this point....... but they open fine when you are going up gears.
Does that make sense??

I see what you're saying......I don't know what I could be.

[THE TECH]

Was this happening before the update?

[Donbona]

Originally Posted by THE TECH

Was this happening before the update?

Yes
I have the previous from latest BMW software on my car.

[w00tw00t]

Originally Posted by Donbona

Ok... im not sure wether its the DCT box or throttle actuators.... but here goes....

When I am accellerating my car is fine but when I am slowing down to approach lets say a bend, I blip down to 2nd gear or 3rd.... take the bend than put my foot on the gas and get absolutely nothing... when connecting the computer to the car it showed that the throttles actuators are not opening at this point....... but they open fine when you are going up gears.
Does that make sense??

does your engine seem to almost die but recover when coming to a stop? I had a similar problem in my previous M3 .. where sometimes when slowing down from a moderate speed to a standstill caused my engine to almost die and then recover .. happened occasionally. It was eventually diagnosed as a faulty idle valve and was repaired under warranty.

[Donbona]

Originally Posted by w00tw00t

does your engine seem to almost die but recover when coming to a stop? I had a similar problem in my previous M3 .. where sometimes when slowing down from a moderate speed to a standstill caused my engine to almost die and then recover .. happened occasionally. It was eventually diagnosed as a faulty idle valve and was repaired under warranty.

No... idle isnt an issue at all...

[w00tw00t]

Originally Posted by Donbona

No... idle isnt an issue at all...

since you're in the UK have you considered taking it to Sal at Evolve? those guys are wizards with M3s.. (assuming you don't want to take it in to the dealer?)

[Donbona]

Originally Posted by w00tw00t

since you're in the UK have you considered taking it to Sal at Evolve? those guys are wizards with M3s.. (assuming you don't want to take it in to the dealer?)

Took it to Sal... he isnt 100% wether its the DCT or the actuators.....
He is the one who initially plugged his computer to my car and together we saw that the throttle actuators were not opening after you floor it just after slowing down. Under normal accell the actuators work fine.

[THE-FN-MAN]

Does it happen in every mode (i.e. MDM or all off such as S6) depending on your speed if you come out of a tight bend and then just hammer it with traction on there might be a delay because the computer knows that opening the throttles will cause wheel spin and it won't allow it. Try S6 and hammer it out of the corner and see if that helps. Good luck with everything

[Donbona]

Originally Posted by THE-FN-MAN

Does it happen in every mode (i.e. MDM or all off such as S6) depending on your speed if you come out of a tight bend and then just hammer it with traction on there might be a delay because the computer knows that opening the throttles will cause wheel spin and it won't allow it. Try S6 and hammer it out of the corner and see if that helps. Good luck with everything

Yep, tried all that.... same thing...
Thanks bro

[truths2k05]

I absolutely hate DCT. Never again am I buying this sort of transmission. It nevers knows what the driver is trying to do. Bmw still does not have the technology to makes these transmissions run smoothly. Since the smg days, they still haven't figured it out. I'm tired of having my car sit at the dealer for 2-3 days, only to have them give it right back with nothing changed. The bogging, lagging, and blipping the throttle when I'm trying to park the car, just plain sucks.

[rjd598]

Originally Posted by truths2k05

I absolutely hate DCT. Never again am I buying this sort of transmission. It nevers knows what the driver is trying to do. Bmw still does not have the technology to makes these transmissions run smoothly. Since the smg days, they still haven't figured it out. I'm tired of having my car sit at the dealer for 2-3 days, only to have them give it right back with nothing changed. The bogging, lagging, and blipping the throttle when I'm trying to park the car, just plain sucks.

you're in a minority. op hope everything works out for you...maybe it's dealer time?

[Donbona]

Originally Posted by truths2k05

I absolutely hate DCT. Never again am I buying this sort of transmission. It nevers knows what the driver is trying to do. Bmw still does not have the technology to makes these transmissions run smoothly. Since the smg days, they still haven't figured it out. I'm tired of having my car sit at the dealer for 2-3 days, only to have them give it right back with nothing changed. The bogging, lagging, and blipping the throttle when I'm trying to park the car, just plain sucks.

Unfortunately I don't have much choice, I shattered my left knee so I can't operate a clutch pedal.

Originally Posted by rjd598

you're in a minority. op hope everything works out for you...maybe it's dealer time?

Thanks bro, tried the dealer but my car is well out of warranty plus being supercharged they won't touch it.

[THE-FN-MAN]

Wonder what would happen if you had someone like Gintani or ESS flash your DCT for quicker shifts and all of that. Perhaps nothing since you said Sal saw that it might be the actuators. But just throwing it out there because I know how frustrating these things can be

[GrussGott]

Originally Posted by rjd598

you're in a minority. op hope everything works out for you...maybe it's dealer time?

Originally Posted by truths2k05

I absolutely hate DCT. Never again am I buying this sort of transmission. It nevers knows what the driver is trying to do. Bmw still does not have the technology to makes these transmissions run smoothly.

Do you have a DCT M3?? Says you have a 6 speed so I'm wondering if you've ever driven one. Also you wrote "it never knows what the driver is trying to do" - mine does what I tell it to do, but then I have never driven it in D so maybe that's what you're talking about?

In any event, for me the SMG/tiptronic transmissions were not any type of benefit. My S4 with tip had a fairly good sport shift program that i was happy with for sporty daily driving but I would never have tracked it.

The DCT, for me, is like nothing I've ever driven - it feels like truly new technology and I've had to learn to drive it just like when I was 13 learning to drive stick.

For me, it feels like the future - I can't imagine ever going back to a manual ... maybe for old times sake, but not for my primary car.

[Donbona]

Originally Posted by THE-FN-MAN

Wonder what would happen if you had someone like Gintani or ESS flash your DCT for quicker shifts and all of that. Perhaps nothing since you said Sal saw that it might be the actuators. But just throwing it out there because I know how frustrating these things can be

No way I would put their tunes on my car... remember I have a different charger.

And yes.... very frustrating...
I did manage to talk to Jeremy from SSP who is a really nice guy to talk to. He told me of a few possibilities that could be causing me this issue but unless I change the whole DCT box I will never know. So it could be a costly experience.

[truths2k05]

Originally Posted by GrussGott

Do you have a DCT M3?? Says you have a 6 speed so I'm wondering if you've ever driven one. Also you wrote "it never knows what the driver is trying to do" - mine does what I tell it to do, but then I have never driven it in D so maybe that's what you're talking about?

In any event, for me the SMG/tiptronic transmissions were not any type of benefit. My S4 with tip had a fairly good sport shift program that i was happy with for sporty daily driving but I would never have tracked it.

The DCT, for me, is like nothing I've ever driven - it feels like truly new technology and I've had to learn to drive it just like when I was 13 learning to drive stick.

For me, it feels like the future - I can't imagine ever going back to a manual ... maybe for old times sake, but not for my primary car.

My m3 is 6spd. And yes I have driven an m3 dct. I drove it on the track quite extensively. It never felt as fast or anywhere near as smooth as my 6spd, of course the dct is faster. In day to day the dct lags, lags, lags. Surges or lags no in between. Sport mode alters it to more surge, but there is still a lot of lag. Drive them back to back and you will see what I'm talking about.

The offensive dct is in my 135i, which uses the same dct as the m3 sans the controller box. It feels no different then the dct in the m3 that I drove on the track. Lags the same,shifts the same. Dct shines once you are going 20-30mph+. Stop and go, or making turns at low speeds is where it rears its ugly head.

The people that say they don't feel the lag or hesitation in their dct at low speeds either don't drive enough or they don't know what to look for.
There has been complaints on the smg and dct gearboxes ever since they came out. I am not alone in this, just check out the complaints at NHTSA, they will go into detail about the issues that I mentioned there.

DCT needs more work from the transmission manufacturers, or bmw needs to have better sensors feeding it the right information to do the job. Dct reminds me of early drive by wire systems, where there is a lag between the right foot and the opening of the throttle, just worse.

Can DCT outperform a 6spd in a straight line, yes. Can DCT be smooth in stop and go traffic, and when slowing down or speeding up to make a turn. SADLY we are not there yet.

[ChrisK]

Originally Posted by truths2k05

I absolutely hate DCT. Never again am I buying this sort of transmission. It nevers knows what the driver is trying to do. Bmw still does not have the technology to makes these transmissions run smoothly. Since the smg days, they still haven't figured it out. I'm tired of having my car sit at the dealer for 2-3 days, only to have them give it right back with nothing changed. The bogging, lagging, and blipping the throttle when I'm trying to park the car, just plain sucks.

Not my experience either, DCT in my car has been flawless. Sorry