Lamborghini Sián is an 819hp Hybrid Bull

Funny, it's using a lithium ion supercapacitor.

Self discharge is usually of the order of weeks to months, so Toyota must just have had an energy capacity issue (not surprising since they hold 25 times less energy than Li-ion batteries per kg - EDIT: this one's only 5 times less). Its trump card is that the charge / discharge power is ten times (EDIT: this one's only three times) that of any battery, which is excellent for maximising regenerative braking, but works fine at low powers too. Supercaps would work brilliantly coupled with a small battery, but that requires complex control which in racing is typically legislated to the hilt...


The 33 hp power rating given for the Sián is that of the electric motor; you don't add the rate you can fill your fuel tank to your car's power output, do you?
It's also only the power rating when used for acceleration; I'd wager it can be pushed much harder than that for short bursts, e.g. in braking...

Not sure I follow your thought process here. Yes it's lithium ion but supercaps are vastly different from regular batteries in the way they absorb and release charge.

Now I'm no electrical engineer, so smarter people please correct me if I'm wrong, but here's my general understanding:
Supercaps - high energy density but limited total energy content, high charge/discharge rate but cannot stop doing either midway (i.e. once it discharges it spends everything it has at once)
Batteries - lower energy density but higher total energy content, lower charge/discharge rate but more flexible discharge pattern (i.e. can discharge to say 50%, hold, and discharge a bit more later)

So even though the Lambo can charge to 100% and deploy all that charge quickly, it cannot store a lot of it and once it's gone, it's gone until the next heavy braking zone. If you're on a track with mostly high speed corners with no heavy braking zones, the system won't ever recharge to 100% and it's benefits will be minimal. Whereas a traditional battery hybrid supercar will still have some charge left and free to deploy it whenever, wherever in this situation.

I'm not talking at all about self discharge in terms of the power store losing electricity long term. Batteries lose a little charge when sitting there for long periods of time, but I'm not sure about supercaps.

As for the power rating, I'm not sure what the issue in my interpretation is. It's basically the extra power the system gives that can be put to the ground. I mean the motor is sitting in the gearbox itself. Can't get anymore direct than that. I just wonder how many people who buys the car will be able to tell the difference of extra 33 hp at full throttle, compared to say, Aventador SVJ given the similar performance numbers.

Don't get me wrong I love the car's looks and the novelty of supercaps in a road car, but IMO the system feels like a quick add on just to say "we've done a hybrid".
 
A partial charge is perfectly viable for a supercapacitor, although the energy stored is proportional to the square of the voltage (but energy is still energy, so that means nothing if you have the right current / voltage control on the charge / discharge circuitry).

You can charge a supercapacitor on cruise like you can a battery. I think this is tightly controlled, if not outright prohibited, in racing; maybe because it's viewed as "inefficient".

What distinguishes a Li-ion chemistry supercapacitor is that it sits somewhere between a "traditional" supercapacitor and a "traditional" battery in terms of its capabilities: average energy density, average power. Best of both?

Being selective about the contributions to the power figure is important because otherwise you could add on the AC compressor and the stereo amplifier etc. etc. to the car's total power figure. If 33 bhp has been added to the car's official figure, then it's for the motor; the capacitor is otherwise unspecified thus far.

A power (/ weight ratio) difference of only a few percent is detectable in my experience, and if you move away from the peak offered by the thermal motor, that 33 bhp becomes a larger proportion of the total power output. When the electric motor is used as "torque fill", it will be very much appreciated, on track or in the city. It's excellent for start-stop driving as well, which is usually a bit of an issue with large, high-performance NA engines.
 
Makes sense, thanks. I wonder if it's possible to drive it on e-mode alone, and if so how far can you go just on the supercaps' capacity. Would be funny to have a silent, 33 hp Lamborghini driving around town :P
 
Makes sense, thanks. I wonder if it's possible to drive it on e-mode alone, and if so how far can you go just on the supercaps' capacity. Would be funny to have a silent, 33 hp Lamborghini driving around town :P
I suspect the capacitor would be able to provide roughly 5 seconds of power.
 
I suspect the capacitor would be able to provide roughly 5 seconds of power.
Quick back of the envelope scribbles suggest that at full power it should be at least 10 seconds depending on the power to weight ratio of the motor (whole motor / supercap unit is 34 kg according to Lamborghini).

So it's possible, but you won't go any real distance on electric alone, certainly not at speed. Just like you can't run a car on a turbocharger alone (unless you convert it to the Brayton cycle...)
 
Honesty,

Ferrari SF90 is a way better deal

£400,000 = around 980hp Hybrid
No argument there. But the Sian is another car that's really just there to fund the rest of the line & in this case, maybe test the waters as Lamborghini moves towards packaging their future V12s as hybrids.
 
No argument there. But the Sian is another car that's really just there to fund the rest of the line & in this case, maybe test the waters as Lamborghini moves towards packaging their future V12s as hybrids.

I'm curious on what the Aventador sucessor will offer. It could rival the SF90 with hybrid tech and similar price.
 
I'm curious on what the Aventador sucessor will offer. It could rival the SF90 with hybrid tech and similar price.
It should be interesting. The Aventador S is $417K right now & I imagine its successor will try to stay in that area rather than mimic the Jota in the $500K+ market. That puts it in an area between the 812 ($365K) & the SF90 ($510K).

However, I think the SF90 is marketed as something you could track fairly hard and might step on the Pista's toes, which is an area the base Aventador really doesn't gravitate towards (else you buy a Jota). It has an Assetto Fiorano version than it's even more track-focused, which reinforces the model's capabilities.
 
Back