ZF Press Release

[mchaskell]

I was poking around ZF's web site and came across this. Warm fuzzy for all Steptronic folks.

Rapid Response and Dynamic

Newly developed automatic 6-speed transmission responds and shifts even quicker.
Further fuel consumption reductions and an enhanced power-to-weight ratio at the same high level of comfort.
New torque converter and highly efficient software revolutionize the multi-ratio automatic transmission.

The use of a new torque converter in combination with optimized transmission control and hydraulics make the multi-ratio automatic 6-speed transmission of the second generation even more efficient than its predecessor; thus, it contributes simultaneously to the generation of significantly increased fuel savings:The gasoline-powered vehicle needs up to three, cars equipped with a diesel engine even up to six percent less fuel.Since September 2006, the new rapid shift transmission is made available in the 3 Series Coupé and the X3 by BMW.

Increased driving dynamics and efficiency
Driving dynamics and fuel consumption play a decisive role in addition to the comfort requirements for a multi-ratio automatic transmission.“The new automatic 6-speed transmission definitely represents a quantum leap in the fields of automatic transmission development." says Dr. Michael Paul, Executive Vice President Technology and Group Executive of the Car Driveline Technology division.“With the second generation of the automatic 6-speed transmission, we have succeeded in improving driving characteristics while, in parallel, enhancing the driving performance even further.It is the most agile automatic multi-ratio transmission ever.”At the same time, the new automatic 6-speed transmission does generate fuel savings; for the gasoline-powered engine, this corresponds to three, for the diesel engine even up to six percent.Moreover, response times have been reduced by up to 50 percent and, for the very first time, direct double shifts without interruption are possible.This type of power enhancement and fuel savings are primarily enabled by the new torque converter which is combined with the optimized electronic transmission control unit and the hydraulics.The rapid shift transmission is designed for an input torque of up to max. 850 Newton meters, i.e. for automobile drives featuring powerful engines with up to twelve cylinders.

The new torque converter
In order to optimize fuel consumption, ZF has developed a consistent shift strategy for the torque converter lock-up clutch with the objective of closing the clutch completely as soon as possible, namely directly after setting off.In order to master vibrations in the driveline successfully and safely, ZF uses the newly developed torque converter:For the gasoline-powered vehicle, this task is covered by a turbine torsional vibration damper; for diesel engines, a special twin torsional damper (Twin TD) was invented.In addition to fuel consumption, also driving dynamics have been significantly improved thanks to early closing of the converter clutch and the compensation of the inertia moment on the basis of the smaller sized torque converter.The thereby improved connection of the driveline to the engine leads to the fact that the driver experiences vehicle responses to accelerator pedal actuation more actively and directly.

Hydraulics and the electronic transmission control unit
What’s new? Well, the automatic 6-speed transmission performs all dual shifts directly; moreover, it downshifts of up to four stages are effected without any time losses or noticeable deceleration.This has been enabled by the further development of the hydraulic system.The respectively needed clutch is directly controlled by a separate pressure regulator so that no additional time is required for jumping a drive stage.This target gear finding mechanism, as it is called, makes the shift process extremely precise.In order to trigger that function as quickly as possible, the improved control electronics are in charge of the corresponding optimum drive stage.The control software “decides” on the basis of the data received on load conditions, the driving situation, and the speed with which the accelerator pedal is actuated, whether downshifts are effected for just one single drive stage or several.This decision depends upon the swiftness for acceleration commanded by the driver.The stronger the driver accelerates, the more dynamic is the way of vehicle speeding up.
No matter whether one gear step or several gear steps are shifted, the response time remains the same.And the latter is extremely low:If - at an approximate driving speed of 70 km/h in the sixth gear- a kickdown signal is received, then the automatic 6-speed transmission needs just 100 milliseconds in order to trigger the rapid changeover from the sixth into the second gear.All in all, ZF was capable of reducing the shift time by half in relation to its previous transmissions.

Further developed gear set
Just as in the case of the predecessor version, the planetary transmission system on the basis of the Lepelletier gear set is at the center of the new automatic ZF 6-speed transmission.Thus, six gears can be realized with significantly less components:In the past, only three gear sets and six shift elements were needed for the automatic 5-speed transmission; today, a simple planetary gear set suffices as well as a Ravigneaux gear set in combination with five shift elements.The result:Considerable weight savings of a total of approximately eleven kilograms have been attained in relation to the automatic 5-speed transmission.The increased use of plastics contributes to the reduction of weight and consequently fuel consumption.Thus, for example, the oil tray is no longer made from metal.

Prospects
Already in 2001, ZF successfully introduced the first automatic 6-speed transmission on the market.In the mean time, automatic 6-speed transmissions have more or less completely replaced the automatic 5-speed transmissions.With the new 6-speed transmission range, ZF is well equipped in order to successfully defend its benchmark position for multi-ratio automatic transmissions in the upcoming years.

Source:
http://www.zf.com/content/en/import/...jsp?dbID=23483

[SF Dede]

Unless it is of the dual clutch variety, or similar technology, I am not really interested. Torque converters? Whatever.

[murellus]

Drive a 335 with step and you'll be amazed. I was...I'm more of a manual guy myself but the technology is definitely good.

[gemini330zhp]

Well I see evoulution has been changing the autotrans great to know.

[d1ez3]

Good information, thanks

[Cuz5150]

I want my 5 minutes back!!!
It's still a bitch stick, it just has an extra gear for people to slush around

[sndprssr]

Way to show your intelligence . What are you 15? Go spend a few years in school and a few in the field then you can talk, otherwise keep your opinions to yourself if they are not contributing to the conversation. Besides, no one asked you to read it...

[JohnnyTT]

Cool to see the "Direct Double Shifts." It can jump 2 gears at once without any delay.

Groovy!!!

[SCMike]

This second generation ZF auto 6 speed definitely got my attention. And I'm an old fart, born when FDR was still alive, my first several new cars had a non-synchro 1st gear (nothing was as satisfying as double clutching and slipping the stick into 1st without a graunch, while the car was still moving). Or owning one memorable Chrysler product that kept on breaking its clutch cable, which required manipulating the manual gearbox without benefit of clutch. And I used to walk to school 5 miles every day through three feet of snow - no, wait, that's a different story.

I have never in my life bought a car for myself that did not have a clutch pedal (for the wife is a different story). But now the 135i and ZF have me considering a change of religion. I am highly amused by some of you youngsters and your gearbox identity crises.

[Cuz5150]

Originally Posted by sndprssr

Way to show your intelligence . What are you 15? Go spend a few years in school and a few in the field then you can talk, otherwise keep your opinions to yourself if they are not contributing to the conversation. Besides, no one asked you to read it...

STFU!! a way to show my intelligence to you! No one asked you to comment on my post. Dont get your panties in a twist because i dont like/can care less about slush boxes. If autos are your cup of tea, then thats great!! Buy the ultimate driving machine and get it with a slush box.
I did go to school, and guess what class/test i skipped??? Auto transmissions:w00t: was not going to waste my time!!

Now i want my 10min back :P

[sndprssr]

If you don't like it don't read the threads on it. No matter how you want to slice it the "slush box" is still faster than your manual and I seriously doubt, judging from your posts, that you have any real knowledge concerning cars, transmissions or the otherwise. So far in your 17 posts you have contributed exactly nothing to these boards, good job, and I'm done. Arguing on the net is like running for the special olympics...I'll not finish that just in case it really would offend someone here.

/hijack

[JohnnyTT]

Wow.. this was a cool post about some great information. If you're going to argue, plz take it elsewhere.

[jeremyc74]

Originally Posted by SCMike

I have never in my life bought a car for myself that did not have a clutch pedal (for the wife is a different story). But now the 135i and ZF have me considering a change of religion. I am highly amused by some of you youngsters and your gearbox identity crises.

The "slushbox" in the 135i (and 335i) makes a very strong case for the modern automatic transmission. It's the best I've ever driven, and if I had to deal with traffic every day I would have given it serious consideration as well.

[sonic0075]

I test drove a 335i sedan, since they didn't have a 135i, because I wanted to see what that that engine would do. I'm usually a manual only type of person, especially with small cars, but was really surprised with the Steptronic trans in the 335i sedan. Is it the same in the 135i? I really want to stay with a manual, but as I get older, I seem to be getting lazier, especially in my line of work. Plus, I will still have my 04 .:R32 with its 6 speed, so I can always drive that when I have an urge to row the gears :biggrin:

[professor]

that's interesting wilhelm - an r32 with stick and a 135 with auto would be an odd combination. if you had to do it again perhaps you would have gone r32 with dsg and 135 with manual - best of both worlds that way.

[sonic0075]

Originally Posted by professor

that's interesting wilhelm - an r32 with stick and a 135 with auto would be an odd combination. if you had to do it again perhaps you would have gone r32 with dsg and 135 with manual - best of both worlds that way.

No, cause I wanted a real .:R32 :biggrin:.