[nonsequitur]

Your observations need to be sorted out, which is what we are trying to do in these threads on CVT Driving Technique, CVT Objective Testing, and several others you are finding in MINII2.

I'm expecting help to better understand the major components (BMW software, Siemens EMS 2000, ZF VT1F CVT Transmission, and inputs like the throttle pedal), and how they work together. If this happens soon, then I think we can make some significant gains on understanding what is supposed to happen and how to manage the whole package (sometimes called Driving!).

There are very low speed behaviors which are internal to the ZF Transmission. I think these are called Crawler and Start-Off functionality, for very low speed movement (driveway creep into the garage as an example) or launch from a full stop respectively. These are hydraulic valving actions to manage the variator pulleys and belt, controlled by the transmission, probably with direction from the computer (EMS 2000) too. All of this relates to 1600rpm in some way I don't understand yet.

So you may be feeling the CVT, or it may be the software (which is what I had assumed all along), or both. It's apparently very complicated to get this slow speed stuff to work well, but I've separately heard that this particular CVT unit (the ZF VT1F in the MINI) and the Audi A6 do a very good job of it. Until the manual cars lose their software problems (the same ones we are seeing in the CVT), I'm focused on those software version iterations (now at 33.2) to resolve these behavior questions.

The CVT is a very capable machine, and better balanced than the others, proven on the track. It is technically forward (most cars will become increasingly digital very quickly). And it seems to be bulletproof mechanically, with lots of protection-of-the-investment benefits if you're inclined to operate near the limits.

A great car that we need to understand better - and we will.

[BartMack]

This is great!- I've finally found the thread where there is excitement about the CVT! I've been nosing around MINI2 for about a week or so, mostly in General Discussion areas.
Most everyone talks about the S, not much zeal for the "automatic". I think it's much more than just an AT!

My CVT is March 03 build, delivered 4/24/03. I'm near the end of break in (at about 1005 mi today)

I also did not know about the SD mode until I read it somewhere on this site a few days ago. I had been using D & Steptronic about 50/50, more steptonic recently as I get more accustomed to the car. It is a blast!!

Mostly I find that D delivers strong enough acceleration, except I have found that on a hot day with the ac on, D doesn't deliver the power I want, so I go manual. I mostly use 1 to start, and the 1-2 shift comes pretty quick after takeoff. I am looking forward to trying SD to feel the difference. I've been waiting until break-in is over.

I am also very interested in CVT driving technique, and will monitor posts, and hopefully contribute.

One curious difference I have to the posted comments I've read is on displayed rpm redline. My first post was kind of 'what's up with this' because I saw differences in photos of which markings were lit.

My displayed redline is 6000rpm. I called the dealer and confirmed that it is displayed correctly on my tach. This must have just been changed from the previous 5500 display.

Also a guy I work with found a really cool animated (simple) web graphic of the CVT in operation. 2 opposing conical cylinders alternately contracting & expanding with a steel belt linking them. I'll try to find it tomorrow & link or something.

[nonsequitur]

The MINI Cooper CVT is the most interesting, and least understood, car of the bunch. I love it still. Entertaining on the track too.

You will thoroughly enjoy SD, but give each of the modes your careful examination, and then SHARE your observations and questions here with us.

You'll be welcomed -- to help us figure it out, since the Owner's Manual doesn't help very much.

[Sejanus]

Quote:

Originally posted by intrigue182
One thing I'm wondering about: when I test drove a CVT Cooper in September 2002, when in slow traffic (foot off the brake, gently giving it gas, going under 5 MPH) I noticed what I can describe as a slight "back and forth" feeling in the forward movement of the MINI. Then, when I drove a new and different CVT at the dealer last month, it was still evident, but maybe just a bit less pronounced.

Is this a CVT quirk? It's almost as if something is "engaging/disengaging/engaging/disengaging" in the tranny or something, only when the car is 'coasting in traffic at around 5 MPH, giving it no or very little gas...

Yeah, it seems to be a CVT thing. Mine does it around 10 mph and we've had a number of people mention the same problem. From other folks' posts and the report from my local service department this is apparently normal operation for the CVT.

[BartMack]

On the interstate today I tried to get a good feel for the accelerator, and I found the resistance point I've read about, a a sort of click-point almost all the way to the floor. Before that the pedal seems smooth with slightly increasing resistance all the way down. After the click-point (as I call it) I guess it goes into 'kickdown' mode.

Found that animgif, its actually drawn by Honda, but makes it very easy to understand (provided it uploads)

[nonsequitur]

That's very good BartMack; it illustrates the variator pulleys and thrustbelt continuously variable positions rather well. I'll need to get my notes out, but we can describe some of what we're talking about using this illustration. Thank you.

In much of what I'm reading, your "click-point" is called a kickdown "detent" that is the actuation for that function from the tranny.

[adgrimes]

Well... Ive spent the last hour reading all your posts. My CVT Cooper is due to be delivered mid july (apparently)... I had an auto Renault Laguna recently as a hire car through work (V6, 3.0L, 24 Valve). This had the kick down point just before the accelerator is floored. My current Honda Civic auto does not have this and it took me a while to get used to. It also had the Step/Tip-tronic gear shift feature, which I found myself using more and more towards the end of having it... When I test drive the Mini One recently, I did not notice the SD feature... How is this enabled?
Please bare in mind that I am in the UK so steering wheel is on the right, accelerator on the right, and to shift the gears into steptronic you move the gear stick to the right...
Thanks for your help... PLEASE keep this thread going as its really nice to have some advice from people who drive their car a bit sporty like I do...

Adam - A very impatient soon-to-be-mini-cooper-owner... grrrr

[nonsequitur]

The transmission is the same, but the lever selection may be a mirror image in your UK car, BUT it sounds like it is exactly the same as the US. Here are the three driving modes again:

Drive ("D" in the speedo) is the Continuously Variable Transmission mode. This is the left side of the selection lever, with P, R, N, D showing.

Sport (some say SportDrive, "SD" in the speedo) provides very similar CVT functionality as D, but with a much more aggressive map, at consistently higher engine rpm to give more horsepower to the computer. This is engaged by pushing the shift lever to the right, but no push or pull.

Steptronic ("1, 2, 3 ,4 ,5 or 6" in the speedo) is engaged from the S (right) shift lever position which first displays "SD", then the virtual gear selection by a single push or pull on the shift lever.

[BartMack]

The 0-60 times I saw on the CVT (10 sec 0-60) were not as quick as I was expecting... I know it isn't a race car (least n'yet), so it's a moot point really, but it feels quicker than 10 seconds to 60 when I accel full force. And when I pass on the interstate it mmooov veess!
It could be the 0-20 range that is slowing it down to a 10 sec time. (CVT reaction/decision time or sluggish ratios designed for lateral stability of Big Gulps? Them 'mericans love their Lincolns)

And still (in theory) I think the CVT should be as quick or quicker than a conventional Cooper because of the potential for variable/optimum gear ratios and no disengagement time to shift gears.

Electric109 said he ran the revs up to 6000 and let the computer do the shifting in his track runs. I can't help but wonder is the computer still trying to save a gallon of gas even during SD track acceleration? (OH my gosh, it's not an economy car is it?!!?) Maybe it's programmed to value efficiency over power even in Sport mode.

My observations so far about acceleration in mine:
1. I am NOT a professional driver! (my track times would probably suck even in a JCW-S!)
2. There's tons of power in the 3500-4500 rpm range. Hitting the gas in this range will knock you back in your seat!
3. 0-20 mph the trans seems sluggish in D or SD, it seems punchier starting in 1st manually.
4. The 1-2 shift under hard acceleration usually bounces the car a bit as 2nd kicks in.
5. I think overall it accels faster w/ manual shifts starting in 1 and shifting around 4000-4200 rpm.
6. Forget "D"


I also wonder if the trans can be programmed for more advantageous gear ratios. I think they should bail on "D" and make the "SD" the basic and program an "SSD".

Does the CVT have a separate processor than the main engine computer? The superchip articles I've read about plugging in a laptop & increasing hp are intriguing!

I wish MINI would develop the virtual manual side of the CVT more, that would be awesome to really have a "dual" trans (lightweight & versatile) that wasn't viewed as "the AUTOMATIC". Shift when you want to, cruise when you want to. Anything should be possible with infinite gear ratios & a computer to manage them.

[ScooterMan]

Have you found that once you put it in Steptronic (shift either up or down from SD) it stays in SD until you come to a stop.

I like the SD and would like to use the Steptronic only for braking (downshifting), but the car seems to want to remain in Steptronic until I come to a stop. This means that I have to use Steptronic for the remainder of the course.

And, of course, your input is very helpful...especially the part about two throttles (normal and step down). If folks thought using a clutch was fun, the permutations of the CVT are almost endless and really require some quick thinking.

[ARitz]

I think everyone is right that the major problem is the 0-20 range where the car seems to be sluggish. On the freeway i had no trouble keeping up with my friend in his Cooper S. But when we got to the lights, he would leave me in the dust.I think this slouch in acceleration is due to the tranny trying to stay smooth, it probably keeps it in the lower rev range in case of stop and go traffic. You wouldnt want it to rev straight to 3500 in traffic .

Anyone ever wonder why the speed limiter is lower on the CVT as opposed to the 5-speed? Seems odd to me.

-Andrew

[BartMack]

I don't know, I'll have to try that. Driving in SD then downshift for braking-? ...will try tonight or tomorrow.

I have found that sometimes around corners I downshift only to discover that the computer has already downshifted, so I end up in a lower gear than I intended.
It's not convenient when watching all those shiny moving cars around me to glance over to the speedo & refocus to see what gear I'm in, so I'm hoping to develop an anticipation of what HAL does before he does it.

Also today while manually shifting I invoked the kickdown mode while passing and the computer wouldn't let me shift, it locked out my input.

About speed limiter- At what speed is it on 5spd & what on CVT? I think the manual says 135mph governer, but would have to look. The car feels like it would do 120mph, 130mph easy. I see why the speedo goes to 150! I'm trying really hard not to get tickets!(so no 120 on freeway)

About engine braking- downshifting out of SD mode worked very nice on curves with lots of go power on the other side, (lots of fun too!) and HAL would allow ds down to redline rpms I think. Once it is bumped out of SD mode there is no clean way back in except a quick left-right to re-engage the program. Doesn't matter if your moving or not.

[nfo]

you've got to listen to the engine instead of looking!
use the force!
you just haven't used steptronic enough yet!
you'll get the hang of it in no time.

[nonsequitur]

Lots of questions since I checked in last, and there are some confirmed answers to at least some of them:

The ZF Ecotronic VT1F CVT in our cars has been designed for better acceleration, reliability, and economy than camparable manual transmissions.

Functionality (of the ZF transmission part) is flexible enough to allow "customer" (read BMW) decisions on things like how many Steptronic "gears" (3, 4, 5, 6, 7 ... 12) are possible for that particular model (wouldn't a 7-speed be a wild conversation over on the Copper S CVT thread!).

Acceleration from the CVT device is intended to deliver each of the benefits mentioned on one of the posts above but this is determined by the mated engine's power band and customer inputs from their computer (Seimens EMS 2000 in the MINI).

Programmed behavior can also be customer specific, so I remain very curious about the "shifting" sensation in SD past the kickdown detent, versus the almost turbine-smooth adjustment just before the detent. This may be in software (33.2), not the transmission design. I will eventually get an answer to this one.

The transmission has a maximum input shaft speed of 6000rpm. Simply, this is the reason for the 6000rpm redline in our cars versus 7150rpm in the manuals.

The transmission does have a separate "computer" for the hydraulic control functions that control the the variator pulleys, thrust belt, and some of the pressure control stuff. But, in the MINI, I'm told nearly EVERYTHING in the car goes through the EMS 2000. Software drives this car, literally.

Now a big one: Left-foot braking does NOT lockout the throttle as it does in several other drive-by-wire cars. This will convert to very useful technique in the Cooper CVT. If you have not tried left-foot braking, pick your first time very carefully because it's weird to get used to and you don't want to pay for somebody's Ferrari at a stoplight crash. The mechanics of this are that you can apply and modulate the brakes for smooth deceleration or weight transfer in a corner, AND keep the throttle open for a "head start" on the next need for power. We'll need to work on this some more.

[adgrimes]

Very interesting reading a few more questions and findings about the CVT gearbox.
Im not sure how many of you have driven "normal" automatic gear box cars, where the car seems to shift for you rather than continuously shifting like the CVT does...
As I mentioned in my previous post, I had a Renault Laguna as a hire car recently. This didnt have a CVT, but the manual gearshift sounds very similar to the steptronic system in the Mini. Things like the Kick down point feature...
My findings in the Laguna were as follows...
When in "manual-mode" pushing the throttle all the way to the kick-down point, the car will not shift for you unless the revs go to high and you are not changing up a gear. When you floor the accelerator (beyond the kick-down point), the car then took over and dropped however many gears it needed to get maximum revs without being redlined... If you leav the throttle beyond the kick-down point, you cannot change gear manually until you ease off the throttle and go back behind the kick-down point.
I guess I will have to wait until I get the CVT to comment on how it feels to drive... I have only ever been driven in a CVT.
By the way, sorry if my post doesnt make sense... I keep reading it over and over again before posting and keep changing from talking about thing first person/second person yada yada yada...

[Paul]

Quote:

Originally posted by johnewald
Lots of questions since I checked in last, and there are some confirmed answers to at least some of them:

The ZF Ecotronic VT1F CVT in our cars has been designed for better accelleration, reliability, and economy than camparable manual transmissions.

<snip>

Acceleration from the CVT device is intended to deliver each of the benefits mentioned on one of the posts above but this is determined by the mated engine's power band and customer inputs from their computer (Seimens EMS 2000 in the MINI).

<snip>

The CVT MINI (according to MINI official figures) is slower and less fuel efficient than the manual. Not by a lot, but it is.

See this new thread for more:
http://www.mini2.com/forum/showthrea...threadid=31590

[nonsequitur]

Thanks for your attention and help.

If you're really not pleased with your own posts, there is an "edit" function in the lower right of the post screen that will permit you-only to go into your own past posts and correct wording, punctuation, or mistakes. It's somethiing like the Congressional Record process; you can end up saying exactly what you wanted to say in the first place!

I added this paragraph to this post using the edit tool, and fixed a misspelled word in the previous one after reading the posted quote just above. The website should now post an edit alert right below so you know I changed something here too.

[nonsequitur]

Paul, Thanks for stepping in with more facts; and keep them coming please.

My earlier post here was written using information from ZF Group about the Ecotronnic VT1F CVT that is used in the MINI in response to the post ahead of yours.

We are seeking objective facts so that the specifications, characteristics, and behaviors of the different components can be properly understood.

From there it should be possible to develop techniques (this Thread) to take advantage of the strengths, and to compensate for any weaknesses or programming decisions. If we can really figure this stuff out, then more informed and persuasive requests, suggestions, or complaints can be offered to MINI.

At the bottom line, I'm thoroughly enjoying this car. It's fun. It should probably be badged "CVT" or something as part of MINI marketing. I also suspect that the "shifting" behavior was not designed into the ZF unit, but was programmed in for some reason (I'm certain I read this somewhere too) by BMW. What else has been programmed in?

We have at least two threads rolling on this. Their activity drops off occasionally, but then people come back strong around some spark. As the driving season gets in high "gear", I expect progress on both Testing and Technique to improve significantly.

[ScooterMan]

You folks are too much.
This thread is great.

[n3nyongmini]

it needs to be longer, cause I still don't have my car.

Maybe it's time to induce.