[Grumbler]

Quote: Originally Posted by jazmini

Grumbler, that's an interesting idea there of your rolling start. I'll give that a try.

not saying you will get rid of the lag entirely, but it does avoid the bucking nature......so the start is a bit smoother.

[jazmini]

Grumbler, you're right, that rolling start is smoother and helps.

Actually the car performs well enough starting out, it's only occassionally that I really wish for more power.
I think I would prefer a CVT S over a regular automatic S. Too bad they won't make one. Now if that S had a Sequential Manual Transmission (SMT), then I'd probably go for that instead.
Overall, I'm very happy with this CVT.

nonsequitur, I hope you're right in that BMW/MINI is working to improve the performance, because, better is .......better! I looked at your post of the Canadian viewing of the CVT in action. Interesting. I can see why the CVT is as smooth as it is and why there are no gears....... unless you want some. You can clearly see the main drive belt, that sometimes is breaking according to another post here. I hope that doesn't happen to me or anyone else. I would like to see MINI put in a better belt, which holds up better and allows us to add performance mods to increase hp!

Vanwall, you're in San Diego. I used to live there. Great place!

[nonsequitur]

I'm not convinced that we've seen the demonstrated need for a stronger Van Doorne belt in this ZF gearbox. There have been a few dramatic stories in these threads, but overall it is a very reliable device to build, drive, and maintain.

What is not widely understood is that this machine is really not a traditional "automatic", and that it's not accurate to expect traditional performance features from the design. Some things are better: fuel economy, acceleration (once underway), and cost. And, some things are not as good: off-the-line launches (because of the clutches).

This general subject of performance discussed in the Forum recently is why I originally got sucked into trying to research nitty details. Some performance impressions just don't match the expectations (both better, and worse) built up by MINI.

This CVT, in fact all CVTs, must be "calibrated" to transmit all of the available power, but (through computer control) they must also prevent belt slippage which can destroy the components. This need for balance simply does not exist in a geared transmission, and this fact leads to many of the comments we've seen in this Forum since it was started.

That's why I've now reduced my wish list to a single item: get rid of the faked geared transmission emulation in the software called "SAT-mode" in the Functionality Map. This behavior is programmed to make the gearbox act like something it is not.

BMW: delete "AT-mode"; enable native CVT-mode for everything, with elements of the Kickdown functionality retained. This would hightlight the unique character of the CVT-equipped cars and make them more valuable long term. It's more fun in CVT-mode, acceleration is quicker, it's honest, and the confusions we've seen described by some people in these threads wouldn't be further confused by the software itself.

The MINI Cooper CVT is a very capable car. It proves that fact to me on the track several times a year. It's fun. The ZF VT1F CVT delivers the driving control of a manual, if you want or need it in a situation. It protects my investment by precisely executing over-rev limits. For that morning drive to work in traffic, wonderful. And we get to the special character of the MINI which is very well complimented by the CVT.

I wouldn't trade it for anything else in the MINI lineup today, and this statement still surprises and makes me smile each time I say it.

[jazmini]

Well said nonsequitur. I agree wholeheartedly. Let's hope MINI responds.

[nonsequitur]

I'd love to see these ideas that people have put in here carried forward by someone in one of the dealers or from MINI.

[mignon]

Quote: Originally Posted by nonsequitur

The MINI Cooper CVT is a very capable car. It proves that fact to me on the track several times a year. It's fun. The ZF VT1F CVT delivers the driving control of a manual, if you want or need it in a situation. It protects my investment by precisely executing over-rev limits. For that morning drive to work in traffic, wonderful. And we get to the special character of the MINI which is very well complimented by the CVT.

I wouldn't trade it for anything else in the MINI lineup today, and this statement still surprises and makes me smile each time I say it.

knowing how enthused i am about driving my mini, many people ask when i will "upgrade" from the cvt to a mcs but i can't even imagine having one for all the reasons you have so well outlined.
i totally 'get' how so many mini drivers appreciate their manual coopers or mcs with or without the jcw kit and all the other 'go' gadgets. but for me, the cvt is wonderful. and yes, such a statement makes me smile with delight too especially when other people talk about the car they would love to have 'cos i already have what i want.

[Grumbler]

so will you upgrade when the steptronic transmission is offered in Jan 05 on the MCS?

[nonsequitur]

I think it's now clear that the 2005 MINI Cooper S will be available with a 5-speed Steptronic (with Steering Wheel paddles) Automatic Transmission using a torque converter (to generate wheel-spin launches). We just don't know the details yet.

[mignon]

Quote: Originally Posted by Grumbler

so will you upgrade when the steptronic transmission is offered in Jan 05 on the MCS?

on that one, i might not say 'no'

[driverphil]

We have an '04 CVT and are quite happy with it. Makes our slush-box ''04 Matrix look like antiquated junk. Don't fix it 'cuz it ain't broke!

[valnmike]

Quote: Originally Posted by nonsequitur

snip... BMW: delete "AT-mode"; enable native CVT-mode for everything, with elements of the Kickdown functionality retained. This would hightlight the unique character of the CVT-equipped cars and make them more valuable long term. It's more fun in CVT-mode, acceleration is quicker, it's honest, and the confusions we've seen described by some people in these threads wouldn't be further confused by the software itself. ...snip

I couldn't agree more. Oh, wait I think that is pretty much what I wished for when this thread started

[caminifan]

Has anyone followed through on their quest for an additional 35 hp (and additional torque)? I am interested to learn if the effort to find the additional hp and torque resulted in improved performance. After reading nonsequitor's (and others as well) contributions to the CVT threads, I wonder whether there will be any benefit gained in 0-60/100 (mph/kph) time. Does the CVT pass the additional hp and torque through to the road (resulting in quicker acceleration); or does it just sop it up (and waste the effort expended in the search for the additional 35 hp)? Between ECU upgrades, cold air intakes and cat-back exhaust, there is a relatively easy source for the 35 additional hp. The real question is whether any benefit is realized.

[jazmini]

There was someone (Robert) who posted here maybe 6 months ago or so (and Robert also posted on the North American Motoring website), who had heavily modded his CVT MC. I asked him if it still was a little hesitant off the line and he answered that it was. He said that the people who drove in it including someone from the dealer all said it had the performance of an MCS. His mechanic (shop who did the work) also posted on the mods he did for Robert (post was on the North American Motoring website -- his name was Graham and his signature was: mckinneymini -- back on Jan 02 2004 -- he is in Texas). Everyone thought the car was awesome!

He did the following mods: ported and polished cylinder head, the bigger MCS valves, mild Schrick Stage 1 camshaft, BMP cold air intake, Milltek header, SuperSprint cat back exhaust, Powerchip ECU, MINI Madness big bore throttle body. He never dynoed the car, but claims they added 50 hp. Other mods were: 17 " wheels with Yokohama ES100's, H-Sport springs, H-Sport control arms, and Alta rear sway bar. [My note: hp claims are finicky, in that everyone (i.e., vendors) claim much more than is likely -- but this modded CVT MINI must be quite fast and a very big improvement! Everyone was real excited about it.]

So, improvements can and have been made. No one knows how the CVT transmission will hold up, though. The CVT transmission doesn't like too much torque, which is the limiting factor in its capability. All the above mods should have added a little/some torque, but certainly/probably added mostly hp. My opinion is that the CVT can handle this, since its off the line acceleration is programmed to be a little slow in spooling up, so as not to be as hard on it.

If you want to go slow off the line, the CVT will react promptly for that. Its when you want to go fast off the line that it will take some time to get going in that mode. Then after a short wait there is a big rush of power (i.e., torque). So, if you had the above mods, I would think you would not want to do really fast starts all the time. The weak part of the CVT just may be the drive belt (although it is steel), as we have heard of two that have broken. But that is speculation at this point in time, as we haven't heard what caused them to break. I don't think the extra mods will harm the CVT in normal driving, even shifting, but that's if you don't floorboard it all the time, or rev it too high when shifting. I personally don't drive that way, as I like to keep the revs generally between 3-4k rpm's when shifting up and down, and that is quite spirited for me (and pleasingly loud too with my intake and exhaust). However, in the SD mode, it shifts at or near redline (5500-6000 rpm's or so) so if I had the above mods, I probably would not drive in SD mode or at least not too often. But that's me. To each his own.

[jazmini]

I was just looking at my printout copies of prior posts, and I see that this CVT version can take 122 ft/lbs torque (165 nm), and MINI rates the torque on the MC at 110 ft/lbs, so that is a difference of 12, which is a lot to be able to add, as most mods add hp not torque, i.e., most power added at higher rpm's. So, that is interesting, as it allows for some modding. However, hp is a different matter. I don't have those numbers, but I think the CVT is not rated to be able to handle too much more hp. But most of the stress on a transmission is in the off the line performance, i.e., torque.

[Mini CVT 4me]

Hi jazmini,
Take a look at the comparison feature in new mini site :
http://www.mini.com/com/en/model_comparison/index.jsp
Shows torque 150 NM on Cooper, and 220 on MCS !! Thats almost 50 pct increase, might be hard to behave if challenged/tempted? They show diesel torque at 180, which I wouldn't mind. And think I read in Diesel thread that there is no CVT option there, maybe due to excess torque?
Sad part if these stats are the numbers for Convertible CVT...
cheers
:-) :-)) :-)

[jazmini]

Mini CVT 4me, I just looked on that MINI website and saw the torque output ratings of the current MINI engines, which is listed in Nm:

Model Torque in Nm

MINI One 140

MC (includes 5-speed
and CVT) 150
Cabrio MC 150

MINI One D 180

MCS 220
MCS Cabrio 220

I think the 150 Nm torque is probably equivalent to the 110 ft/lbs listed in the stated American statistics for the MC engine. Cheers.

[nonsequitur]

These appear to be the 2005 specs, which are slightly different (bigger numbers) than the 2002-2004 specifications. The Cooper was 149Nm and it's now 150Nm, as one example, raising the US measurement from 110ft-lbs to 111ft-lbs?

[Mini CVT 4me]

Hi Jazmini,
Sorry, I read your two consecutive threads ( 1 and 2) together. I thought you meant the CVT can take the kind of power that Robert's car puts out. In fact, if CVT is capped at 165 nm, that mean most we can reasonably hope for in CVT is more or less 10 pct improvement in torque.
Wonder if aftermarket chips can be tuned towards instead of HP, or are the two indirectly linked?
cheers
:-) :-) :-)

[nonsequitur]

We've got a whole new group of listers in this Forum now, and there is a need to bring some of these ideas and questions forward for them too.

Here's a link to one of the threads (there are more) where the question of adding more power to the CVT was explored:
Got a letter from ZF

165Nm is not the torque limit of the ZF ecoTronic VT1F CVT that's being installed in the MINI Cooper and MINI One. That 165Nm number is the ZF-designed tolerance for the physical unit equipped with a 24mm (versus 30mm) van Doorne steel pushbelt.

The MINI has been "calibrated" (a very careful word) for 149Nm (plus or minus a very small number, much less than "16Nm"). I'm thinking that the new 2005 torque figure of 150Nm was chosen so that it is bigger than last year (showing an increase like the Cooper S), but still within the very small tolerance available. This is not just a "warranty issue"; it's about how the device and the software actually function.

I've likened this environment to a "spec engine" series or the sealed Rotax motors in some karting classes where changes can be many things mechanical and driver-related, except absolutely no changes to the motor. That's the MINI Cooper CVT.

I've got no problem with it now that I understand, but I still wish that MINI/BMW would help us by explaining what's really going on ... and disabling the "AT-mode" confusion.

[cjgpers]

I think it's worth noting a few things about the background and history of the ZF VT1x family of CVT gearboxes.

The first car to have this gearbox fitted, in VT1V form, was the MGF. Back in 1999, this article described how "MG transmission engineers have worked with transmission supplier ZFST of Belgium to produce what is surely the most innovative gearbox......" From this it's clear that the ZF VT1x gearbox was originally designed around the performance characteristics of the MGF (and now MG TF120) engine, so it's worth looking at that engine's performance characteristics:

MG TF120
Max BHP (Ps) = 120 @ 5500rpm
Max Torque (Nm) = 165 @ 3000rpm

MINI CVT
Max BHP (Ps) = 115 @ 6000rpm
Max Torque (Nm) = 149 @ 4500rpm

ZF's own web-site states the maximum torque as 165Nm. That's with the 24mm thrust belt. It's the CFT30 gearbox that has a 30mm thrust belt, and that can handle 310Nm. It's no coincidence that the MG TF120 has exactly 165NM of torque, and is the reason why the CVT equipped MG TF is the only model to use this "de-tuned" version of the 1.8 K-series engine.

This suggest so to me that the absolute maximum for the gearbox is 165Nm, otherwise I'm sure MGR would not have used the "de-tuned" 1.8 engine. It also suggests that 120bhp is safe, but no more otherwise again, I think MGR would have increased the bhp on the TF120 by now to, for example, 135bhp as used in the TF135.

One other observation is that the MINI CVT needs a higher RPM to achieve maximum torque (4500rpm vs. 3000rpm for the MGTF), and that may explain why a MINI CVT is slower off the line that an MGTF. I've had the opportunity to compare both, since I own an MG TF120 and my son (cooper_sport) owns a MINI CVT.

It's also interesting to note that Mercedes are adopting their own CVT gearbox for the A-Class, with a 30mm thrust belt, but this will notably have a torque converter (instead of wet-plate clutches). As this article states - "This helps the A-Class to move off particularly comfortably, yet very briskly". Getting a CVT-equipped car off the line quickly either means slipping the clutches to the maximum torque figure (4500rpm for the MINI-CVT, 3000rpm for the MG TF120), or using a torque converter as a torque multiplier from stationery.