Hybrid vs ICE

[Erunanethiel]

On hypercars such as the LaFerrari, P1 and 918, would you gain more horsepower if you took out the electric motors and made the internal combustion engine bigger by the weight of the electric motors, would you end up with more horsepower?

Shorter version: Would the said hypercars be any more powerful if they weren't hybrids but had larger engines, would they have more power, keeping the total weight of the car the same?

[Dashy902]

If you just took out the electric motors, probably not.

However, if you take out all the ancillaries (batteries, generator units, etc.) that having the hybrid comes with, you'd need a massive engine, to come to the same value, which would undoubtedly make the car more powerful.

The point of a hybrid isn't strict lightness or speed though, it's to give a 'green' appearance for shareholders and the like.

[Jolle]

Supercars or hypercar aren't about the most power per weight. If that would be the case a simple big turbo would be always make a hypercar better.

[mertol]

They advertise them to be about speed tho and this is false advertising. If they were they would be more like radical - not so powerful but 2-3 times lighter.

[dans79]

They advertise them to be about speed tho and this is false advertising.

They are fast, you seem to be mistaking power for speed. the 918 & a Tesla are both faster than a Chiron.
https://en.wikipedia.org/wiki/List_of_f ... celeration

One of the reason for this, is that electric motors can deliver maximum power at 0 rpm, something an ICE can't do. They are also using the electric motors to even out the power curve, just like they do in F1. This makes them faster, and more drivable to boot.

[Tommy Cookers]

'maximum power at 0 rpm' ?

no - that would require infinite torque

even maximum torque at 0 rpm would only be developed if current was not controlled - but it is (for good reasons)
EVs have constant torque (rising power) up to some speed then constant power (falling torque) as speed rises further
so aren't so different to an ICE job (and also benefit from gears)

[Andres125sx]

'maximum power at 0 rpm' ?

no - that would require infinite torque

EVs have constant torque (rising power) up to some speed then constant power (falling torque) as speed rises further
so aren't so different to an ICE (they also benefit from gears)

Sorry but IMHO the red part a bit too optimistic

ICE:


Electric motor:


There´s a basic difference wich is crucial in normal use, electric motors provide maximum torque from 0rpm, not at zero as you pointed out, but once it start moving even slightly it´s already providing maximun torque, while ICEs need to rev up to around half its max speed to enjoy a similar delivery

[dans79]

'maximum power at 0 rpm' ?

no - that would require infinite torque

I miss spoke, torque is what I meant.

Work is a 5 alarm fire today, and i'm doing 3 things at once.

[Tommy Cookers]

there was a time when gears were for starting from rest and climbing mountains

the most sporty Jaguar XK engine spec was for the E type (marketed 2 years ahead as the S option in the 3.8 litre XK150 car
giving at 20 mph 184 lb ft torque and (max) 211 lb ft at 110 mph
the E type gave top gear acceleration from 6 mph without needing clutch slip

at that time some other cars probably had wider torque curves
in this respect modern cars are rubbish
but people today love to shift gears

[Rodak]

Off topic, but the 1964 (and other years) Chevy Impala used a two speed automatic transmission mated to a 300 h.p. 327 c.i. engine. Of course there were other combinations of engines and transmissions; the Hurst 4 speed box would lay rubber in 4th gear, as I know from personal experience.

With the 8 speed boxes and the electric deployment we're almost to a CVT mode in F1.

[Andres125sx]

there was a time when gears were for starting from rest and climbing mountains

the most sporty Jaguar XK engine spec was for the E type (marketed 2 years ahead as the S option in the 3.8 litre XK150 car
giving at 20 mph 184 lb ft torque and (max) 211 lb ft at 110 mph
the E type gave top gear acceleration from 6 mph without needing clutch slip

at that time some other cars probably had wider torque curves
in this respect modern cars are rubbish
but people today love to shift gears

Interesting, but you perfectly know not stalling and being similar to an electric motor are completely different things

Also, ICEs with powerful low band always see their high band lessened, while electrics don´t need to sacrifize anything to be extremelly powerful (a lot more compared to ICE) at very low rpm

[Tommy Cookers]

[quote=Andres125sx] .........ICEs with powerful low band always see their high band lessened, while electrics don´t need to sacrifize anything to be extremelly powerful (a lot more compared to ICE) at very low rpm[/quote]

that's just it ......electrics always sacrifice something if they are trying to be all things to all men

so a compromise is reached
remember the 'motor' drive synthesizes from/to battery DC a 'motor' supply continuously variable in voltage and frequency
the best efficiency comes from designing around one voltage and one torque ie one power and rpm
but to get high torque at low rpm we need high current which makes everything less efficient and bigger
to get high rpm we need to design for high voltage

for these reasons Tesla uses an induction 'motor' and automatic-type gears (in their main product)
the drive cannot supply the 'motor' to enable full torque at zero rpm (efficiency falls at high slip)
the 'motor' will stall in the sense that the torque is less at zero rpm ie the car is as limited by hills as an ICE car
neither the drive nor the 'motor' are particularly efficient (but they are cheaper and simpler than other types)

proponents of electric or part-electric supercars should check the type of electrics and their built-in limitations

[mertol]

They got the acceleration part ok but the handling is crap. They would go faster around a lap if they remove the hybrid stuff from the car.

[dans79]

They got the acceleration part ok but the handling is crap. They would go faster around a lap if they remove the hybrid stuff from the car.

How about some proof, because I'm not taking your word at it.

[mertol]

Well I'm not going to gut a P1 to prove a post but we can do a little calculation
Let's say grip is roughly proportional to (weight + downforce)^0.8, inertia is only proportional to weight and the pace in turns is grip/inertia.
P1 hybrid turning will be (1395kg+600kg)^0.8/1395kg=0.3129
non-hybrid will be (1395kg-170kg+600kg)^0.8/(1395kg - 170kg)=0.3318
or 6% increase in acceleration during turning, braking and traction

Now for straightline performance we have
hybrid: 903hp/1395kg=0.647
non-hybrid: 727hp/(1395kg - 170kg)=0.593
or 9% decrease

so basically the hybrid is slower in the turns, has more power but can't put it down and has to brake earlier but given long enough straight it will beat the non-hybrid on top speed

sources: http://www.evo.co.uk/ferrari/laferrari/ ... s-stack-up
https://en.wikipedia.org/wiki/Tire_load_sensitivity