[Shep]

I wonder if CVT is getting a bum rap in road tests (Edmunds and others) for its acceleration from a standing start. When the stopwatch is started, the driver hits the gas pedal (accelerator), then slowly (at first) the CVT gets going. After that, it seems, acceleration is fine.

Surely, to be fair, this "hesitation" in a CVT should be compared to the time that has to be taken, in a manual shift, to engage the gear, to increase the revs and to release the clutch. In measuring 0 - 60 timings with a manual transmission car, I'll bet they already have engaged the gear and have revved the engine pretty high before they start the stopwatch.

If a CVT were timed against a manual that began in neutral from a standing start, I suspect the CVT would be closer to the manual in its time to 60 mph.

Any thoughts on this? My CVT is on the ocean at the moment, so in a few weeks we'll be able to test it out for ourselves.

It seems the majority of CVT drivers have little to no problem with the "hesitation" from a standing start. I know everything is relative to what you think is normal. And, "normal" automatic transmissions don't have much of a hesitation at all. However, the CVT does apparantly have one.

Our CVT MINI just got scheduled for production. We have not test driven a CVT and so have no first hand knowledge of what it's like. One might think it imprudent to buy something this major without trying it out first. Well, we bought our first MINI after a five minute test drive and though impulsive it was a very good decision.

This car will be my wife's. She is not a "lead-foot" at all so her requirements for fast get-away and bruising acceleration are not high. I'm thinking she will love this car.
I have a hard time believing that the CVT MINI is all that slow. There are just too many enthusiastic CVT drivers on the forums.

[acetonic]

I'm one of the happy CVT owners. I think you really can't appreciate it until youve driven it about a month or so. By then you will have learned how it behaves and learned to drive accordingly. No complaints here. It's the quickest auto I've driven. When I get my S next year I can have the best of both worlds.

[AprilWhine]

I think that would be cute, for you and Vanessa to have matching cars.

[nonsequitur]

You've seen the other threads in MINI2 I think, so let's focus on your question. You're more than partially correct. The question we haven't answered properly anywhere is: How does one Launch the CVT most effectively?

There is hesitation, in all cars, some much more than others.

Stopwatch times are handled as you state, which does give the manual an advantage in these competitive comparisons. Revs would be up [what do people use, 3000rpm?], clutch depressed, DSC off to get some wheelspin, ... All the car's systems and the driver are "staged" before the stopwatch is started, just as you said. Everyone wants the launch to be quick, so the typical process used is mildly cheated as you imply.

In the CVT, lots of change is going on at launch. We need to figure out the appropriate Driving Technique to minimize how many of these changes occur after the stopwatch is started, AND how to properly "stage" the car's systems and driver. See below for my basic ideas on this.

The ZF VT1F Continuously Variable Transmission (CVT) has its own computer and internal functions that "interface" with the MINI EMS2000 computer. A hydraulic function called "Fast-off" gets the whole thing going. I have no idea how this actually works. The six-disk oil-bath Forward clutch pack smoothly (progressively engaged I think) transmits power from the motor. We proved that there are important differences between the "program" for D, SD, and Steptronic, and how the e-throttle works. D has heavy management in some program like "Smooth to 50[mph]" that makes it nice to drive but slower than SD.

All of this may get back to simple technique, to take time-consuming adjustments out of the CVT's process. Here's a place to start, but we need to figure out how to incrementally improve the steps:

SD selected. Left foot on the Brake. Right foot steady on the e-throttle to detent (which sets a "Target Speed" in the computer). Revs come up, clutch pack engages, driveline gets "tight. Release the brake. The transmission still goes through the fast-off process, but once you get going, the CVT (in the CVT mode, not "shifting") really performs.

This is a wonderful car, complicated maybe, but a joy to drive in the right conditions. It outperforms many, many cars in autocross and on the track. Great fun, and the most flexible MINI in the product line.

[punkeyfunky]

Quote: Originally Posted by acetonic

I'm one of the happy CVT owners. I think you really can't appreciate it until youve driven it about a month or so. By then you will have learned how it behaves and learned to drive accordingly. No complaints here. It's the quickest auto I've driven. When I get my S next year I can have the best of both worlds.

I have to agree that the CVT is great - once you get used to it. If you can dump everything you've learned about 'boxes alltogether, and drive the CVT 'fresh', you'll appreciate that its still a reasonably quick motor.

As for fastest auto.... my MC doesn't even come close to my Supra

Lee aka PunkeyFunky

[Arnel]

To me, it's more of a delay. I have 3 other cars with the classic slush box. And they don't have this delay. But don't get me wrong. I love my CVT. This delay is *THE* only complaint I have with my MC. When the CVT gets going it's an absolute blast to drive.

And I don't think there is anything to make it faster. I tried all different launch techniques and the delay is there. I did it from 'D' and 'SD' from zero rpms. And I've done it in 'SD' with a power brake at about 2500 rpms. Same. Still the delay.

I went to the dragstrip to quantify the delay. My 60 foot times was a sky high 2.9 sec. It's just not fast. Let's just say that the CVT MC is not a drag car.

And just 2 days ago I was finally able to install my Green Twister intake. I retested my launches. Same. The delay is still there. But once the rpms get above 3000, the car pulls a little more. Throttle is more responsive. And the sound is awesome.

So again, the CVT ;aunch delay is there. But I can live with it. This is not a drag car or a street light racer. It's a fun little car that takes turns hard and still gets going pretty good when the rpms are kept over 4000 rpms.

[brave1]

Sometimes it seems I get a quick start with my CVT ..and other times it just kinda takes it's time to get moving. But once it's going, I can fly...and since I'm not a drag racer, that's just fine with me.

[nonsequitur]

The Cooper CVT is not a "fast" drag racer, but I'm still curious if it could become a VERY "consistent" drag racer??

I had a gloriously fun track today that may generate some comment on the Cooper CVT driving technique thread after a good night's rest. We got this machine to work today.

[AprilWhine]

I had a small hesitation , but it's mostly gone now that the break in period is over. I wonder if the cars tested are new, or have a few miles on them?

[Arnel]

I'm almost positive it would been a very consistent bracket racing drag car. But in stock trim it's a low 18 sec car. Sorry, but that's way too slow for me. I've got a low 12 sec bracket racing Z-car right now. And these days 18 seconds is just plain not respectable out there.

I've got the intake now. And when I get the exhaust, I'll go back to the track and prove that it'll run consistent 1/4 mile times. Hopefully in the 17's.

[nonsequitur]

Arnel, I respect that point (neither the MINI or Mini are "fast") and I agree with your fun factor wants too. The rush of a fast car is amazing.

There's still a question I've been unclear about in this bracket racer subject. If I were spot on consistent with that 18sec 1/4mile time as we emerged from your crowd-pleasing launch and tire smoke, would I beat your 12sec run (if it were off a little bit)?

Two stories:
Portland, OR, 8/29/03. A big bad Chrysler long-wheelbase V10 turbo-diesel pickup truck rumbles up to the line alongside a new Z-06 Corvette. Turns out they're buddies. Truck wins on time, Corvette has higher speed. The crowd goes nuts, and lots of people start talking about the coming diesel (torque) invasion of America. The truck clearly wins the crowd.

Portland, OR, 8/30/02 (one year earlier). A cute little '67 Mini Cooper S avoids the water to putter up to the line as a nitrous-puffing Ford Mustang fills the bleachers with smoke from the burnout area. The Mustang is GONE into the night, but somehow the old fart in the Mini gets a good reaction time and leads off the line for enough feet to get cheering attention. The crowd goes nuts, even though the Mini runs 78mph at 18.2 sec (I think it was), and lots of people crowd around the car and smiling driver as we push through the lineup again for another run.

Which of these drivers had the most fun? Under bracket racing rules, could I have won against the Mustang?

[Arnel]

You have a good point there. As the slower car you are the underdog which makes it that much sweeter to win.

But IMHO, bracket racing a slow car and fast car are 2 totally different worlds. Bracket racing a slow 18 sec car is *TOO* automatic. You literally just hit the gas and go for a 18 sec leisurely cruise down the strip. There's just not excitement there for me. It will be consistent. And if you have good reaction times, there's a high probability of you winning. And sure winning is very FUN!

But bracket racing a fast car is such a HUGE high. And my turbo Z-car gives me that. It's got big fat drag radials on the rear wheels. You roll up to the waterbox and wet the tires. You rollup and wait for the officials to signal you to do your burnout. Then you go through the almost ritualistic burnout procedure with the blowoff valves going off. Then up to the staging lights. The tree falls. And you hope the tires grip. Boost comes in hard and pray you don't spin going into 2nd gear. At full boost the car is GONE. And it's steady as an arrow for next 1/4 mile as you constantly eye your opponent. You accellerate through the next 1320 feet preparing to blip the throttle if you have to. And peddling the gas at the top end of the track is where the real fun is. This is the drama of bracket racing. This is what keeps me racing. So 115mph later, you're looking for the win light.

As far as the fun factor is concerned, an 18 sec bracket racing MC just plain can't compete. Again, I'm positive the MC CVT would be very consistent. But for me, that's half the problem. Each race would be too methodical and somewhat boring. Not enough of a challenge for me. Maybe too easy. IMHO, much of the drag racing experience is lost here.

[nonsequitur]

I'll give you each of the points you made, and move on with the thought that consistency of the CVT is a potential winner. If you can find a way to get your yucks from a slow win, then go for it in the Cooper CVT. Thanks!