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The Porsche Taycan's Two-Speed Gearbox

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Re: The Porsche Taycan's Two-Speed Gearbox

#201

Post by kwhitefoot »

jaclaz wrote: post #23

Once upon a time there were cars with a "normal" 4 speed (+reverse) gearbox and an added "overdrive" box (that if I recall correctly could only be used in 3rd and 4th gear), surely there were a few Triumph's and some Volvo station wagons, they had a button/switch on the gear stick that activated it electrically. https://en.wikipedia.org/wiki/Overdrive_(mechanics) This device (with all the possible evolutions in these…

Loads of cars had an overdrive and it made a significant difference to fuel economy at high speed.

I think the difference here is that the Taycan has a kind of automatic gearbox that can operate while under hard acceleration whereas, as far as I remember, you only pushed the overdrive button when you had reached cruising speed.

Re: The Porsche Taycan's Two-Speed Gearbox

#202

Post by enragedcacti »

whalesalad wrote: post #129
cat199 wrote: post #125

Earlier quoted context omitted.

someone this close minded would likely not be considering electric in the first place (and would probably whine about porches being mostly v6 and not v8/10/12)

Close minded? Huh. You won’t find a CVT in anything but a budget economy vehicle. If you want performance, you don’t want a CVT. If you want to prioritize efficiency over everything else (including reliability), a CVT is fine.

CVTs grant you the ability to maintain peak power at all speeds for acceleration and you don't have any losses to shifting. If you look at recent Civics for example Sport trims with more horsepower and a manual trans will lose out or tie CVT models in 0-60 and 1/4 mile times despite the CVTs having bad launch characteristics. And this doesn't even touch on how torquey they can feel at higher speed relative to a standard trans at the same HP.

I won't question your claims about reliability but CVTs are actually pretty performant within their segment, they just dont make the Vroom Vroom shifty noises that some car enthusiasts equate to performance.

The primary issue with CVTs (as others have mentioned) is that they can't be strapped to engines that make more than ~200 HP.

Re: The Porsche Taycan's Two-Speed Gearbox

#203

Post by compiler-guy »

Dylan16807 wrote: post #156
compiler-guy wrote: post #106

Earlier quoted context omitted.

Are saying that Porsche--which is spending billions of dollars on the Taycan and its transmission--is doing this for no good reason? "People care about range and reliability."--Certainly some, perhaps most people, do. And Tesla serves that market very well. But that isn't Porsche's market. Porsche's target market cares a lot about handling, and performance in track-like conditions.

> Are saying that Porsche--which is spending billions of dollars on the Taycan and its transmission--is doing this for no good reason? Yes, they are. They are saying that "better on a track" is a bad reason, and "it makes more money" is a bad reason. That is not a claim that Porsche is incorrectly engineering to reach their goal, or doing anything unprofitable. It's an opinion.

That's a different opinion than the one being expressed and therefore the I'm discussing. The argument I'm talking about is the one which claims, "There is no advantage to a two-speed transmission". You seem to be saying that the advantages of such a transmission are bad reasons to build it.

But those are different arguments.

Re: The Porsche Taycan's Two-Speed Gearbox

#204

Post by zaroth »

ztjio wrote: post #176
zaroth wrote: post #160

Earlier quoted context omitted.

This is more of a function of battery chemistry on the S/X - the Model 3 does not have the same power restriction under load.

You're super 100% wrong. The model 3 absolutely does have the same restriction under load. I have no idea where you're getting your ideas. I am a Model 3 owner, I assure you it will reduce power after a time. No need to take my word for it though you can find plenty of autobahn demo videos showing it. It's not terrible but it is a thing and it's "worse" with track mode. Numerous "sporty" car reviews also mention this…

Super 100% wrong! That’s impressive for a clearly factual statement. It is indisputable that the Model 3 does not have the same power restriction under load, and that is primarily attributed to the new battery chemistry.

That is not to say that the Model 3 is entirely unlimited in its power delivery. But a 2018 S/X will go into a low-power mode before you can even finish one lap on the ring and the Model 3 will not. The stock Model 3 Performance brakes will overheat however.

I’ve watched several videos where Bjørn Nyland pushes his 3P to top speed for sustain periods and does not see any power limiting. He shows the same driving on a Model S which gets power limited.

A cursory Google search finds several Tesla forum threads showing people with 3P not being power limited on the track.

I am also a Model 3 owner, and I’ve never seen it reduce power, but I’ve never driven it faster than 110mph for a few minutes, and don’t take it on the track.

The main issue I’ve read about 3P is that the brakes overheat. It needs carbon ceramics on the track.

It is universally acknowledged that power delivery on the Model 3 is better than S/X.

Re: The Porsche Taycan's Two-Speed Gearbox

#205

Post by compiler-guy »

giobox wrote: post #189
kenhwang wrote: post #134

Earlier quoted context omitted.

The Taycan currently only comes with two brake options: carbon surface coated brakes or full carbon ceramic brakes.

Porsche have said in many interviews the coating is for cosmetics rather than performance. Like most electric cars, when driving “normally” you don’t really ever touch the brakes as the energy regen that kicks in when you step off the accelerator pedal slows the car down so effectively. Porsche were worried the discs would develop unsightly surface corrosion from lack of use for some drivers - the coating keeps them…

The Taycan freewheels when you take your foot off the accelerator and only regenerates when you hit the brakes. This is quite different than most other electric cars.

Re: The Porsche Taycan's Two-Speed Gearbox

#206

Post by jaclaz »

kwhitefoot wrote: post #201
jaclaz wrote: post #23

Once upon a time there were cars with a "normal" 4 speed (+reverse) gearbox and an added "overdrive" box (that if I recall correctly could only be used in 3rd and 4th gear), surely there were a few Triumph's and some Volvo station wagons, they had a button/switch on the gear stick that activated it electrically. https://en.wikipedia.org/wiki/Overdrive_(mechanics) This device (with all the possible evolutions in these…

Loads of cars had an overdrive and it made a significant difference to fuel economy at high speed. I think the difference here is that the Taycan has a kind of automatic gearbox that can operate while under hard acceleration whereas, as far as I remember, you only pushed the overdrive button when you had reached cruising speed.

Yes, that is part of the evolutions I mentioned, what I meant essentially was saying that a two speed gearbox (electrically/hydraulically operated) reminds me more an overdrive box (which is actually a two speed gearbox electrically/hydraulically operated) than an actual 4/5/6 speed manual or automatic gearbox.

The actual use of the old overdrive was to lower revs of the engine (please read as save fuel) at a given speed, or (I know, not the actual intended use) to increase top speed, which is exactly what the new Taycan gearbox seemingly is used for (automatically, not manually, of course).

I remember a diesel Volvo station wagon (must have been a volvo 240 or 244) where in order to overtake someone at 120-130 kmh, the procedure was:

1) turn A/C off

2) accelerate as much as possible in 4th gear

3) push the override button

that gave just a little more speed.

Re: The Porsche Taycan's Two-Speed Gearbox

#207

Post by gonehome »

fgonzag wrote: post #185
gonehome wrote: post #37

Earlier quoted context omitted.

I think the early versions of the original Tesla roadster had gearboxes with multiple speeds, but Elon eventually got rid of it and settled on just having one for later versions of the roadster (and all subsequent Tesla cars). I think they found it didn't give much of an advantage when it did work and that they generally just didn't work very well.

And anybody who has driven a Porsche knows what an immaculate steering and transmission feels like. I seriously doubt Porsche would release something that was not up to the standard of the regular vehicles.

I had the recent boxster and was a fan (though it was stick).

I have driven the older “tip-tronic” (I think that was the name) paddle shifters though and they weren’t very good at the time. Supposedly they’ve improved since then though (that was probably 2009 or so).

Re: The Porsche Taycan's Two-Speed Gearbox

#208

Post by esotericn »

Ididntdothis wrote: post #124
esotericn wrote: post #96

Earlier quoted context omitted.

I do it quite often, but it really depends on location I think. In more rural locations you'll commonly have a 90 degree turn onto a 60-70mph road. I probably wouldn't if it were 3s 0-60 though.

The tire wear for repeated 3s 0-60 must be enormous.

At 4s it's not too bad. I mean, I don't have anything to compare to, but we're still talking tens of thousands of miles per replacement.

Obviously that's not like, a full throttle acceleration and slowdown constantly, just merges.

Re: The Porsche Taycan's Two-Speed Gearbox

#210

Post by wkearney99 »

fgonzag wrote: post #185
gonehome wrote: post #37

Earlier quoted context omitted.

I think the early versions of the original Tesla roadster had gearboxes with multiple speeds, but Elon eventually got rid of it and settled on just having one for later versions of the roadster (and all subsequent Tesla cars). I think they found it didn't give much of an advantage when it did work and that they generally just didn't work very well.

And anybody who has driven a Porsche knows what an immaculate steering and transmission feels like. I seriously doubt Porsche would release something that was not up to the standard of the regular vehicles.

Agreed. Daily driving in my 958 GTS is great. Long highway stretches are fantastic. But it's not until weekend autocrossing that I really get to feel how well tuned a 2-ton SUV can be. Turning in times in the middle of the same pack as the coupes is fun.

People that haven't driven a modern Porsche just do not grasp how precise the driving experience can be. It's astounding how well-tuned their vehicles are.

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