Performance automatics

[Dimman]

Originally Posted by madfast

LOL i just edited it right before you posted!

and for that matter mitsu also loves the CVT. but i forgive them because they also have the SST dual clutch. subaru? they dont have any performance automatics. imo this is a shame...

in japan they have a crappier version of the STI with an auto, but that's not enough...

Probably by seconds, heh.

A future dual clutch would be interesting. Does Aisin make any? Since they are part-owned by Toyota that would likely be the source of future ones. I would guess maybe they would start with the Lexus IS if they were going to?

[madfast]

Originally Posted by Dimman

Probably by seconds, heh.

A future dual clutch would be interesting. Does Aisin make any? Since they are part-owned by Toyota that would likely be the source of future ones. I would guess maybe they would start with the Lexus IS if they were going to?

i dont think they make a dual clutch. and to be honest, if they can make an auto as good as the IS-F, do they really need to?

[serialk11r]

A bit random, but in the rather far away future we might see electrically coupled drivetrains, which would be what a CVT should've been had it not been for its high friction and low torque capacity, but this would probably require high temperature superconductors to make it worthwhile. Motor pulls a generator hooked up to a voltage converter hooked up to a motor connected to the wheels.

[Want.FR-S]

Originally Posted by serialk11r

A bit random, but in the rather far away future we might see electrically coupled drivetrains, which would be what a CVT should've been had it not been for its high friction and low torque capacity, but this would probably require high temperature superconductors to make it worthwhile. Motor pulls a generator hooked up to a voltage converter hooked up to a motor connected to the wheels.

Why so complicate? Iirc the tesla roaster only has one gear called "drive" and the electric engine just change the rpm for speed. The torque band for the engine is flat from 0 rpm. No need for gearing just need to tell the engine how much torque is required.

[serialk11r]

False, the torque band is not flat, it drops off, but they did some compensation to let it rev higher. Electric motors are good for street driving precisely for this reason; they don't need to rev to the limit for power. Now an ideal electrically coupled drivetrain would be able to have the ICE pull a generator, and feed the power back out to the motor at the correct voltage/current. However due to current limitation a superconductor is necessary to wring out maximum power at all speeds. The control circuit would need to be designed for this of course.

[1660]

Originally Posted by madfast

you mean like in the LF-A?

You must have a fairy godmother.

http://www.roogio.com/toyota-ft-86sc...boxes-and-lsd/

“The manual will offer quick and precise shifts with a short-throw, while the automatic transmission will feature sporty shifts controlled by steering-wheel-mounted paddle shifts,”

[Want.FR-S]

Originally Posted by serialk11r

A bit random, but in the rather far away future we might see electrically coupled drivetrains, which would be what a CVT should've been had it not been for its high friction and low torque capacity, but this would probably require high temperature superconductors to make it worthwhile. Motor pulls a generator hooked up to a voltage converter hooked up to a motor connected to the wheels.

Originally Posted by Want.FR-S

Why so complicate? Iirc the tesla roaster only has one gear called "drive" and the electric engine just change the rpm for speed. The torque band for the engine is flat from 0 rpm. No need for gearing just need to tell the engine how much torque is required.

Originally Posted by serialk11r

False, the torque band is not flat, it drops off, but they did some compensation to let it rev higher. Electric motors are good for street driving precisely for this reason; they don't need to rev to the limit for power. Now an ideal electrically coupled drivetrain would be able to have the ICE pull a generator, and feed the power back out to the motor at the correct voltage/current. However due to current limitation a superconductor is necessary to wring out maximum power at all speeds. The control circuit would need to be designed for this of course.

So I said the torque band starts flat (almost) from 0 rpm does not mean it remains flat all the way (infinite power from the battery?). That does not negate the fact that in Tesla roadster does not have transmission gear because their motor has a flat torque curve from 0 (almost) to 5100/5400rpm.

Here is the link from Tesla motor about their technology:

http://www.teslamotors.com/roadster/technology/motor

So if we delve into the details of this electrically-couple transmission:

1. on the input side, we have a ICE burning fuel using 30% of its energy (according to Tesla) to create mechanical rotation torque
2. this rotation power is turning a generator to generate electricity, stored in a big capacitor or a secondary battery, and power will be loss during this conversion.
==> although using superconductor can reduce loss on power during electrical energy conduction, but by how much *in this application*? what is the electrical energy loss caused by the wires in this short distance (relatively speaking) within this device? what is the frictional loss of energy that cannot be saved by superconductor?
3. using control logic to tell another motor to spin at a different rate and consume energy from that big capacitor or battery. That is another energy conversion and energy loss is deem to happen. 12% loss on energy again by Tesla.

So in short, you have directed the energy from mechanical to electrical, and then from electrical back to mechanical for the sake of changing gear. The equipment required could be huge (2 motors/generators with a big capacitor/battery) plus the associated energy loss for the whole transaction. Plus the costs of doing all of these. What is the efficiency gain by this approach?

Again, why so complicate?

P.S. I failed to see how you can use superconductor in this application. Granted superconductor causes little or no energy loss during electricity transmission. But that is not the main point here in transmission design. There are other important factors to consider rather than the power loss in wires. Superconductor is not the *magical* thing that can fix everything.

P.S. 2: just a side note, if you really want to drive the wheel using electrical motor, why not hook it directly to the electrical engine, and wait, isn't that the Tesla Roadster? Silly me.

[madfast]

Originally Posted by 1660

You must have a fairy godmother.

http://www.roogio.com/toyota-ft-86sc...boxes-and-lsd/

“The manual will offer quick and precise shifts with a short-throw, while the automatic transmission will feature sporty shifts controlled by steering-wheel-mounted paddle shifts,”

meh, that's just marketing talk. i'm waiting for details like shift speed and exactly when the torque converter locks up, etc.

you know a tranny is good when they publish a technical paper to the press. the lack of such a press release would mean it will be ordinary.

[1660]

Originally Posted by madfast

meh, that's just marketing talk. i'm waiting for details like shift speed and exactly when the torque converter locks up, etc.

you know a tranny is good when they publish a technical paper to the press. the lack of such a press release would mean it will be ordinary.

I think it will be a $2000 option. Still want an AT.

[Mr.Jay]

couldnt find where they mention LSD in that article at all

am I just blind or what

[1660]

Originally Posted by Mr.Jay

couldnt find where they mention LSD in that article at all

am I just blind or what

Yes, you are blind. Read the title!

http://www.roogio.com/toyota-ft-86sc...boxes-and-lsd/

[madfast]

Originally Posted by 1660

I think it will be a $2000 option. Still want an AT.

most torque converter autos are like $1k option. im inclined to believe that it wont deviate too much from the norm. but even hypothetically im going to get the auto no matter what. the ONLY thing that would ruin it, is if its total crap like the IS tranny. total crap in its operation, not the actual hardware. in the IS there is no true manual mode. the paddles merely let you choose the top gear. its no different than the old school PRND321 but done in a fancy way....

but the IS-F does have a true manual mode, as does the miata/RX-8 which the FT is supposedly sharing the auto tranny...

[Mr.Jay]

Originally Posted by 1660

Yes, you are blind. Read the title!

http://www.roogio.com/toyota-ft-86sc...boxes-and-lsd/

lol sorry but dont you find it odd that the title is the only place the mention it even tho they brought up transmissions plus its still missing one more word behind it. STANDARD

[1660]

Originally Posted by Mr.Jay

lol sorry but dont you find it odd that the title is the only place the mention it even tho they brought up transmissions plus its still missing one more word behind it. STANDARD

Aren't you being a little insecure? You want it to have the word STANDARD?