Before you bash CVT's too much, check out the winning SCCA "A-modified" Auto-X cars. These are the fastest Auto-X cars on the planet and they typically use CVT's (and two-stroke snowmobile engines). Why? Because they rev up so fast that shifting causes loss of time (and the two-stroke has a narrow happy RPM range).

 

Penforhire,

Where was CVT bashing going on? I think every response so far was giving the technology and efficiency a thumbs-up. The only question is whether it takes away from the pleasure of shifting yourself.

And yeah, those little 2-stroke beasts (more like overgrown Karts really) are pretty cool. The reason they are really able to use a CVT in a racing application like that is low torque.

Clark

 

I can think of a few places where i short shift to reduce torque and enhance stability...have an adjustable CVT would make those transitions much faster than shifting a traditional gearbox. turn 6 at willow springs is the first place that comes to mind, where you crest a hill in the middle of a turn.

Another thought...always leave the engine at peak power RPM, and then in corners (like 2 at WS or thunderhill, or 8 at WS, etc.) instead of steering with the throttle you can steer with the gearbox by constantly changing the gear ratio, and thusly changing the torque to the road and causing understeer/oversteer to guide you around the turn.

 

now that i think of the constant throttle idea, that leads me to start thinking that with a CVT you could efficiently use a turbine engine in a racecar. As long as you had a good turbine...like that motorcycle jay leno is said to have...

 

I'll be picking up a Honda Insight CVT very soon, I'll let you guys know about the drivability.

 

CVT trannies have finally hit the larger car market, the 2002 Audi A4 comes with a CVT tranny. They have spent a lot of time on their Audi multitronic

 

Josh3io,

Good point about the short-shifting, though I wonder if this type of maneuver would be as necessary with a racing-oriented CVT as we've been discussing. The reduction of torque I can see, though mostly in rainy type situations. In my experience the enhanced stability is usually more a matter of not wanting to have to shift at a different point in a set of corners that would be more difficult. This would no longer be necessary with the CVT.

Clark

 

Well, thank you all for the comments and my final thoughts
are that CVT is a very efficient tranny althought a manual
is always fun to play with.

 

So CVT S2000? Would you buy it? Would it detract from the racing experience? Would a CVT vs Manual S2000 beat out the manual with equal drivers? Would quarter mile ET's be better? Would long engine life be better?

Personally I would not mind a CVT S2000 than an unlikely Auto S2000. If CVT offers the best of both worlds and not too many disadvantages, is this the next step in transmissions? Is it correct to say CVT has infinite gears or no gears at all?

I would kill to have CVT on my mountain bike..

Pros:
1. No shifting, misshifts or wrong gears caused by human error
2. Maximum fuel economy
3. Optimal ratios with maximum torque
4. Faster than any human could possibly shift
5. Drives like an automatic
6. No such thing as a clutch drop, side-stepping, heel-toe, double-clutching

Cons:
1. Have to convince older style drivers CVT is better
2. Have to get used to constant high RPM - is a tach even needed anymore?
3. More weight - as much as an automatic?
4. No engine braking
5. Throttle steering could be a problem?

 

A CVT S2000 would beat a manual S2000 both
on the 1/4 mile and the 0-60 because it shifts
faster than a manual and it revs high.