Ferrari LaFerrari vs Mclaren P1 vs Porsche 918

I guess I don't know what youre asking. Its my understanding from what ive read you can capture energy from a brake system. Anyway, I know the p1 has a MGU so it does capture kinetic energy (KERS) which is the only point I was making. Someone commented the p1 only uses ICE which is not correct. Thats my only point.

 

Magneti Marelli supplies electric engines for the LaFerrari, Maranello?s first hybrid car | Magneti Marelli Checkstar

 

Thanks for answer, I have one last question: If Laferrari had to V8 turbo engine would you use this car as a base platform for some of your projects?

 

Allow me to explain. I used to work in a oil rig, a modern one that uses brake regen (electric braking) rather than conventional drum brakes (mechanical braking) to brake the drawworks or hoist. When braking, the hoist motors generate a lot of current which is not needed so this current is simply fed to resistor grid and dissipated off as heat - it is wasted. The KERS in the P1, LaF, 918 (and MGU-K in F1) work the same way except the current generated by electric braking is stored in a battery and reused.

So what you read is right, energy is being captured from the brake system. But the brake system referred to here is the MGU, not the disc brakes.

 

xku807 thanks for the explanation

I read the laf captures energy from the front brakes but I don't know how accurate that is or how it works.

 

None of these 3 cars capture energy from the mechanical brakes front or rear. It is the e-motors (which brake the engines in generator mode) that do that.

 

Interesting. So laf and p1 are basically the same? Aside from capacity of course.

edit: I'm sure its been discussed among the 100s of pages I haven read so no worries I'll search around someday, or not

 

Yes they are basically the same except P1 halts all kinetic energy harvesting (I think) when the mechanical brakes are deployed so that MGU braking (which is variable) doesn't affect the consistency of feel of the mechanical brakes.

 

None really. The 458 has been outperforming the GTR on a regular base in independent tests.

 

Theres a youtube video that shows the dash of a p1 driver while on the brakes and the battery charge increases (quite rapidly) but its not clear if that's gas regen or MGU regen or both. My guess was both because the charge jumps so quickly, but who knows. I guess it doesn't matter as long as the charge is maintained. One thing no one knows about the 3 systems is the efficiency of each; ie one may not have something the other(s) have, but it may not need it either .

 

Wouldn't that cause a considerable braking effect when lifting the throttle pedal, which would be very noticeable to the driver?

 

If it's both and there's no difference between it and LaF & 918, what's all that talk about McLaren not implementing brake regen so as not to compromise brake feel then?

 

Depends on the ECU programming. My guess is when coasting in high gear (low rpm), there is light harvesting. Heavy harvesting probably occurs when you lift in low gear (high rpm) and it will feel like engine braking in a manual tranny car.

 

For a one off perhaps. For a race car no as our CF chassis/tub/cockpit is much more LMP1 and we believe will be enable a body with much higher aerodynamic efficiency than any existing passenger car Chassis/Tub.

 

You almost got it

Kinetic energy is the energy an object possesses due to its motion. The faster you go, the more kinetic energy you have and the more you will be able to harvest.

 

you can define your car as a real lmp1 road homologated car?

 

Funny. Was just thinking the same thing.

 

SCG 003 is as much LMP1 as is possible within GT3 rules and MUCH more LMP1 than any existing GT car. There will be a road legal version.

SCG LMP1L (If we are able to sell enough road cars to keep our racing operation going) will be derived from SCG 003C and when her racing days are over we will make her road legal for me and any customers who race along side us should they desire.

 

Ugh.... not this again.

 

For the upteenth time, the P1 doesn't regen. Regen means capturing otherwise wasted energy and covert that to electricity. P1 doesn't capture anything. It uses unneeded engine power to recharge.

 

Ha, agreed for sure! Amazing how things don't stick here. It's like the thread starts over every few days.

Guys, these systems are very simple, at least for LaF. It has an electric motor that's basically connected to the rear wheels and can act as a motor or a generator. The software controls that. So when you need power, it's a motor. But when it can act as a generator without the driver noticing it, it does. The quality of the software is the key. You can hide the generation when braking, when the rear wheels are spinning, and any time the ICE is asked to generate more power than you need. For the latter, TCS used to knock down engine power when it saw the wheels about to spin by closing the throttle among other things. Now we can kick in the generator to take power away from the ICE. The driver doesn't notice the difference. We either add power to the ICE (motor) or take it away (generator). This happens continuously.

And LaF adds an small second generator that's powered off the ICE to keep the battery topped up and power all the electrical ancillaries. This generator operates all the time, even when idling. So essentially the LaF batteries are charging all the time and it would be nearly impossible to discharge them, especially on the street.

I'm sure P1 and 918 are very similar in this regard, although 918 is much more complex due to the 4WD.

 

Sshhhh/Hush

Funny. When some here want to talk about the P1 braking feel, all of a sudden it DOESN'T employ regenerative braking; consequently that's why it's brake feel (if not it's performance and wear) were alleged to be so good vs the competition.

However, when speaking about it's electrical system, battery set up, energy recovery prowess: All of a sudden it magically DOES EMPLOY regenerative braking. You can't make this up. Lol

There are NO FACTS during this discussion, or almost any during this 600 page thread. Only movement of the goal post, or FLAT EARTH!!

 

Still completely wrong - you haven't done your homework and are now being consistent with inaccurate statements. The number of times you repeat this will not increase its chances of being accurate.

From one of McLaren's lead engineers who developed their MCU:

The difference with the P1 and these other hybrids is that the level of kinetic energy being recovered does not increase when the brake pedal is applied, therefore energy harvesting does not supplement the brakes in the same fashion that the 918 and LaFerrari do, but the P1 is still capturing free energy to recharge the battery. Yes, it does also use excess torque from the engine to regenerate the battery but that is not the exclusive method of recharging.

I also doubt that this energy harvesting ceases in the P1 when the brake pedal is applied as xku807 has surmised but I'm yet to find anything that absolutely confirms/denies that. If anyone else has a source for that detail one way or the other I'd appreciate reading it.

>8^)
ER

 

The part you don't get is that it is possible to regenerate battery power using kinetic energy while off-throttle or braking without using the regeneration effort as the primary means of slowing the vehicle. You can have both, you just have less regeneration in the method employed by the P1 and as everyone who has driven the car has stated, braking feel is not compromised exactly as their engineering team intended.

>8^)
ER

 

More fuel to the fire... LOL

https://www.youtube.com/watch?v=bfLqa4vlmFI