Gearbox: totally unnecessary.

[JimBob]

Shortcomings? A gear box is used to change the speed of a motor which will increase or decrease the torque of that motor as there is a trade between RPM and torque.

 

[Dee]

Shortcomings? A gear box is used to change the speed of a motor which will increase or decrease the torque of that motor as there is a trade between RPM and torque.

True but every motor has its rpm limit.
Torque has no limit, theoretically.

 

[Avantgarde]

No.
First gear is for fast acceleration, hence the threshold of 0-65-ish and overboost for 2,5 seconds when using LC.
That's why the rear motor is bigger.
Second gear is for efficient highway cruise (hence the smaller front motor).


Electric motors have a completely different torque curve so that's total nonsense.
Porsche wanted to go as fast as possible, simple.

My point is that a two-speed isn't quicker (and therefore unnecessary) than a set-up with a bigger motor with lower gear ratio (like @Jhenson29 correctly stated).

Using a single gear with a lower gear ratio vs the 2nd gear set up would result car running out of steam towards the top speed given dramatic drop in torque after 12K RPM. That is why tesla had to develop the carbon sleeved design in plaid to increase torque at higher RPMs to make it work w in a single gear set up.

 

[Avantgarde]

I think you're missing the point of this topic.
It's about why a two-speed gearbox isn't necessarily better than a bigger motor.
Tesla Plaid just prove that it's quicker without a two-speed gearbox but with more motors (which is kind of a bigger motor).
Or a Lucid Air.
Nevertheless, it's so much fun to out-accelerate Tesla's, Lamborghinis, Ferraris, Audi RSs and AMGs.

Everybody seems to be missing your point. Is there a chance your point has a logical fallacy? You are starting with your own presumption that "the only reason Porsche must have put a first gear is to improve 0-60mph there can not be any other reason period because that is the only thing I care about so should Porsche". You completely ignore the fact that adding a first gear, in addition to improving the 0-60 time, lets you put a longer second gear compared to a single gear. A longer second gear likely not only improves efficiency at higher autobahn speeds (at which taycan is more efficient than teslas) but also flattens the acceleration curve and prevents the vehicle from operating at crazy inefficient high RPMs at or very close to top speed. I completely understand this preference as Porsche wants to make the entire band of the performance usable vs Tesla and other newcomers seem to be more focused on printing the best numbers on a spec sheet.

 

[Avantgarde]

Most of the Teslas except carbon sleeved motor Plaid, have single gear set-ups that are unnaturally short, that results in the POWER curve of the engine dropping drastically after only 70-75 mph. (And yes I said power curve not Torque curve! - which is crazy) This yields a very odd unnatural high speed acceleration profile. Post 70 mph, friction increases exponentially with speed and while you need exponentially more power your power decreases almost linearly with RPM! Most likely driver here was around US being the primary market for Tesla initially, where speed limits are typically around 70-75, they wanted to make the car as fast as possible up to that speed for "wow factor", and completely ignored the higher speed implications (massive inefficiency and significantly decreased acceleration towards top speed). If they were focused on finesse and natural driving dynamics, they would either put a taller gear ratio at the expense of a little longer 0-60 time (driving enthusiasts would not care), or if they are so obsessed with keeping the 0-60 time low, they would put a 2-gear set up, similar to Taycan.

 

[Archimedes]

If the Taycan were single speed and had only the second gear ratio, I’d still be interested, but if it were just that first gear, no way. Annoyingly low to me.

 

[Avantgarde]

If the Taycan were single speed and had only the second gear ratio, I’d still be interested, but if it were just that first gear, no way. Annoyingly low to me.

If I had a 4S like you, I would be fine with driving in second gear only. I have a RWD and that downshift makes a whole lot difference!

 

[xyeahtony]

Im pretty sure the gearbox was installed so the Taycan could cruise at high speeds more efficiently. Remember, this is a german built and designed car, so driving on the autobahn is going to be the first priority. At the time, the P100D could go 0-60 in like 3 seconds sure, then the battery would overheat after 15-20 minutes at top speed.

Taycan is designed to go 200km/h++ for sustained periods, and without the gearbox im sure the efficiency would be terrible. Thats why the Taycan seems to beat EPA range ratings when driving at 70mph nonstop on a freeway continuously. Those tests are designed for short, slow trips. That's also why Teslas seemingly never hit their EPA range rating driving on the highway as well.

 

[JimBob]

Thats why the Taycan seems to beat EPA range ratings when driving at 70mph nonstop on a freeway continuously. Those tests are designed for short, slow trips. That's also why Teslas seemingly never hit their EPA range rating driving on the highway as well.

Below is a link to the EPA testing procedure. From this you can see why the Taycan readily beats its estimate.

https://www.epa.gov/greenvehicles/t... driven is recorded,the city or highway cycle.

 

[Dee]

I love that up and downshift!​

Especially when using Sport sound. ​

 

[Andy0565]

Let’s face it , Porsches are totally unnecessary.

Too fast, too luxurious, too expensive. Performance and handling totally unnecessary. £4K brake options unnecessary, Mamba Green - VERY unnecessary, variable light roof, ridiculously unnecessary.

Thank goodness for unnecessary!

 

[jijitalia]

So the Taycan has a 2-speed gearbox.
As we all know, a gearbox is to overcome the shortcomings of an engine/motor.
So why did Porsche make a gearbox as electric motors really don't need a gearbox after all due to their power and torquecurve.
I guess it was to defeat Tesla but in the end it isn't that quick after all, still ridiculously quick though...

So, my conclusion is that it only added extra weight and that has killed the extra performance (and efficiency) which I think was the whole concept of adding a gearbox: to improve performance.

What Porsche should've done is raise the ratio more cuz only then it would benefit the performance (if you wear proper shoes that is).
I'm talking 0-60 times here.
Ok, you'll loose some topspeed but still it would make much more sense.

What are your thoughts about the advantage of a gearbox in the Taycan?

wasn't a matter of capability of making A LOT of launch control (with it massive power) ?

 

[whitex]

Let’s face it , Porsches are totally unnecessary.

Too fast, too luxurious, too expensive. Performance and handling totally unnecessary. £4K brake options unnecessary, Mamba Green - VERY unnecessary, variable light roof, ridiculously unnecessary.

Thank goodness for unnecessary!

I don't think you understood the point of this thread. It's not whether or not it's worth buying, but rather does the 2 speed gearbox give the owners any benefit at all, or is it a less than optimal solution to shortcomings of the motors, adding unnecessary weight to the car. It's a free mandatory option for anyone buying a Taycan (it shows up as an option, but you cannot deselect it).

 

[Andy0565]

I don't think you understood the point of this thread. It's not whether or not it's worth buying, but rather does the 2 speed gearbox give the owners any benefit at all, or is it a less than optimal solution to shortcomings of the motors, adding unnecessary weight to the car. It's a free mandatory option for anyone buying a Taycan (it shows up as an option, but you cannot deselect it).

My response was ‘tongue in cheek’. It wasn’t supposed to be taken seriously. But there is a serious point to be made and that’s this.

Porsche build sports cars and although the Taycan isn’t a sports thoroughbred it’s from the same stable and this will guide the creation of their products.

Every Porsche can stop from 60 in half the time that it takes to reach it. Is it necessary for a Turbo S to reach a standstill from 60 in less than half the time that it takes a basic RWD model? No, of course not, but that’s what Porsche do.

So, is it necessary for a Taycan that’s doing 130 mph on an autobahn to be able to reach 160 in the blink of an eye? Of course not, but it’s what Porsche do.

As for the range argument, so what? A Model 3 has a far better range and a superior charging infrastructure. It’s also 1/2 to 1/3 of the cost, so if a few extra miles are that important, buy a Tesla.

I do get where the thread is coming from. But when you talk about ‘optimisation’ all a Porsche engineer is going to hear is ‘compromise’.

The Taycan has a two speed gearbox because it makes it drive like a Porsche.

 

[tchavei]

I don't think you understood the point of this thread. It's not whether or not it's worth buying, but rather does the 2 speed gearbox give the owners any benefit at all, or is it a less than optimal solution to shortcomings of the motors, adding unnecessary weight to the car. It's a free mandatory option for anyone buying a Taycan (it shows up as an option, but you cannot deselect it).

I guess the main purpose is the efficiency around 110-120km/h (70-75mph) which is the speed limit on highways in most Europe (and the world?). It makes totally sense wanting to have the car crushing at lower rpm to save energy giving it more range making it a perfect car for long trips. Is it perfect? Of course not. It's a Porsche. It has to give the owner the feel of a Porsche and act like it. So I believe the gearbox main purpose was to add efficiency at highway cruising speed. The added bonus of quicker 0-100 numbers and the constant torque pull way beyond 120km/h are nice but I'm not sure if that was the main goal on that Monday morning when one of the engineers walked into Porsche HQ and said "Hey, let's add a 2 stage gearbox"