Porsche 997 GTR Hybrid

[Spyderman]

The new race car is the Porsche 911 GT3 R Hybrid and is based on the 911 GT3 RSR. Unlike conventional hybrids such as the Toyota Prius, the 911 GT3 R Hybrid uses a system similar to the F1-style Kinetic Energy Recovery System (KERS) in which an electro-mechanical flywheel is used to store kinetic energy created under braking. The flywheel, which spins at speeds of up to 40,000 rpm and is located where the front passenger normally sits, can then be tapped to release its stored kinetic energy in the form of electricity, into a pair of 80 horsepower electric motors mounted on the front axle and driving the front wheels, while the gasoline engine powers the rears.
The system works in conjunction with the car's 480 horsepower naturally-aspirated 4.0-liter flat-six engine and provides a maximum eight-second burst of propulsion to the front wheels at the push of a button, delivering the boost necessary to maximize exit speed from a corner or to pass another car. - Motor Authority

[gwyllion]

A schematic picture of the KERS system can be found here.

I guess the system is a bit similar to the hybrid Toyota Supra HV-R. However it only works on the front wheels and uses a flywheel instead of supercaps.

[Spyderman]

Here are some actual pictures of the car:

[knighty]

while this looks impressive, this looks like it will also well support the fact that flywheel based hybrid systems are horrendously expensive and bulky considering the mild-hybrid performance they deliver........but it will be interesting to see how it performs, its also good to see such a car company embracing hybrid technology........hopefully more will follow, but along with Ferraris recent concept hybrid I do detect an amount of lip service and window dressing with no real intentions of launching a road relevant version, lets hope I'm wrong.

[Spyderman]

"After its debut in Geneva the 911 GT3 R Hybrid will be tested in long-
distance races on the Nürburgring. The highlight of this test programme will be the 24 Hours on the Nordschleife of Nürburgring on May 15th and 16th. The focus is not on the 911 GT3 R Hybrid winning the race, but rather serving as a spearhead in technology and a “racing laboratory” providing know-how on the subsequent use of hybrid technology in road-going sports cars. - Porsche PR

[Bentley03]

My understanding of this technology is limited, but am I right in thinking the type of hybrid technology used here is not transferable in line with LMP hybrid technology as permitted under ACO 2011 LMP engine regs?

[gwyllion]

I also find the choice for a flywheel rather surprising. It would be nice to see how it compares to the supercapacitor solution of the hybrid Toyota Supra.

[gwyllion]

Originally Posted by Bentley03

My understanding of this technology is limited, but am I right in thinking the type of hybrid technology used here is not transferable in line with LMP hybrid technology as permitted under ACO 2011 LMP engine regs?

That is right. The ACO rules will not allow flywheel solutions, nor propulsion of the front wheels.

Energy recovery systems will be free, provided they respect the following rules:

• Recovery of energy from the brakes on the 4 wheels or from the heat of the exhaust.
• Only the rear wheels can be used to drive the vehicle.
• Electric systems are allowed only to recover energy from the brakes.
• Energy can only be stocked in the form of electricity.
• The car’s minimum weight will be identical to that of the other LM P1s using conventional engine technology (petrol or diesel): 900 kgs.
• The internal combustion engine and the electric motor must be controlled by the driver using the accelerator pedal (push to pass buttons forbidden).
• The quantity of usable energy stocked on board the vehicle must not exceed 1 MJ.
• Installation of systems enabling the power to be controlled at the entry and exit of engines/generators and the energy dissipated on a lap of the circuit at the exit of the motor/generator.
• The ACO will impose its own safety regulations.

source: http://www.lemans.org/sport/sport/re...hybride_gb.pdf

[gwyllion]

According to http://www.autosport.com/news/grapevine.php/id/81402 Porsche is using the Williams Hybrid Power system (so not the Flybrid solution).

[Spyderman]

Originally Posted by Bentley03

My understanding of this technology is limited, but am I right in thinking the type of hybrid technology used here is not transferable in line with LMP hybrid technology as permitted under ACO 2011 LMP engine regs?

Perhaps Porsche knows something about the 2012 regs, as they have said that the LMP1 (if it came about) would definitely not be in 2011, but maybe in 2012...or maybe no LMP1

[knighty]

that makes sense, the Williams system is a much more integrated system, as the flywheel is effectlivley the rotor of a brush-less motor, so its like a flywheel-motor........ the Flybrid system is just a spinning flywheel and the transfer of output power and converting it into electricity is a more complicated affair........but saying that both systems are still very complex!

[gwyllion]

Are you sure that the Williams solution is much more complex than striclty electrical KERS systems? If I read the (not so technical) description of the system, the flywheel acts a "plugin replacement" for a electrical battery or supercapacitor pack. Taken from http://www.williamshybridpower.com/

The flywheel is electrically driven, and can be considered as an electro mechanical battery, which can replace a conventional battery or Ultra capacitor pack in a hybrid system.

[Spyderman]

But if the flywheel" can be considered as an electro mechanical battery" doesn't that take care of the " Energy can only be stocked in the form of electricity" issue?

[knighty]

Originally Posted by gwyllion

Are you sure that the Williams solution is much more complex than striclty electrical KERS systems? If I read the (not so technical) description of the system, the flywheel acts a "plugin replacement" for a electrical battery or supercapacitor pack. Taken from http://www.williamshybridpower.com/

ahh those clever marketing boys.......they forgot to mention the need for liquid cooling, side mounted radiators and a snakes nest of cables and hoses.......its not that simple......... but I will admit its by far the best flywheel system to use if you have a burning desire to go that route, as Porsche obviously did........ but its certainly not the most efficient system, there will be nothing but significant losses associated with the conversion of mechanical to electrical and back to mechanical power again on the traction motors mounted on the front wheels, no matter how efficient your power storage device is.........but it will work and they will generate good PR, best of luck to em.

I can also see that system fitting very well into an LMP car.......I bet the ACO are willingly waiting for the phone call from Porsche, I'm sure the ACO will offer Porsche big favours to get them back into LMP1.

[Félix]

If Porsche can help the ACO write decent hybrid rules, I'm all for it.

Seriously, performance hybrids make the most sense when electric motors drive the front wheels and give "push-to-pass" boosts of power.

[gwyllion]

Originally Posted by knighty

they forgot to mention the need for liquid cooling, side mounted radiators and a snakes nest of cables and hoses.......its not that simple

Batteries need to be cooled as well, either with forced air or with liquid cooling.

Originally Posted by knighty

but its certainly not the most efficient system, there will be nothing but significant losses associated with the conversion of mechanical to electrical and back to mechanical power again on the traction motors mounted on the front wheels, no matter how efficient your power storage device is

Efficiency is only 1 aspect. Weight and reliability are important as well. The system has to handle a lot of charge/discharge cycles during a 24 hour race! Personally I don't know whether electrochemical batteries are much better for the latter aspects. Toyota has proven that supercapacitors are up for the job.

[gwyllion]

Originally Posted by Félix

Seriously, performance hybrids make the most sense when electric motors drive the front wheels and give "push-to-pass" boosts of power.

Push-to-pass improves racing in sprint races. However, improved fuel economy is more important in endurance racing and for real life applications.

By allowing to drive the front wheels you are effectivily allowing 4 wheel drive, which has been prohibited for eternity. Toyota has shown that you can develop a competitive solution for endurance racing by primarily driving the rear wheels: the Supra HV-R has a 10 kW electric motor in each front wheel and a 150 kW motor on the rear axle.

[knighty]

Originally Posted by gwyllion

Batteries need to be cooled as well, either with forced air or with liquid cooling.
Efficiency is only 1 aspect. Weight and reliability are important as well. The system has to handle a lot of charge/discharge cycles during a 24 hour race! Personally I don't know whether electrochemical batteries are much better for the latter aspects. Toyota has proven that supercapacitors are up for the job.

not all batteries need to be cooled as such, but they certainly work better if kept in a lower temp, like not in the engine bay.........it depends what betteries you are using, typical batteries used in hybrid applications like ultra-capacitors and lithium-ion do not need cooling. Ultra capacitors are generally favoured as they can re-charge exceptionally quickly, but are a bit bigger in volumetric size......... we have an ultra-capacitor bank here at work and it can be 100% filled (from empty) in a matter of seconds, hence their appeal for a motorsport like dutycycle. one of the other benefits of ultracapacitors is they can be broken down and distributed about the vehicle for more efficient use of the package space available, they are not necessarily heavy either when compared to a lead-acid jobbie.


yup, weight and reliability are well important I agree........this type of hybrid is not one of the "light" options, there is a lot of gear there.

[Spyderman]

Yes, apparently 130Kg worth

[JAG]

But like those dual clutch gearboxes, the benefits of the technology for road car use are so huge, manufactuer's will overcome the size and weight obstacles, initially by making weight savings in other areas, as on the F430.

[gwyllion]

Originally Posted by knighty

not all batteries need to be cooled as such, but they certainly work better if kept in a lower temp, like not in the engine bay.........it depends what betteries you are using, typical batteries used in hybrid applications like ultra-capacitors and lithium-ion do not need cooling.

The KERS systems in F1 last year required additionally cooling. E.g., according to http://www.youtube.com/watch?v=ZIQ3jMtPIQ8 Ferrari cooled the electric motor as well the Li-ion battery.

I wonder whether Bosch is involved in the Porsche 997 GTR Hybrid. There is some interesting background information about their KERS solution on http://www.racecar-engineering.com/a...s-modular.html In that article the Bosch Motorsport R&D manager suggests that flywheel might indeed be a better option for endurance racing instead of Li-ion batteries.

Notably for endurance racing Bosch’s Motorsport R&D Manager Oliver Wildner suggests that despite the ACO ban “for endurance racing, maybe flywheel storage is better. Its really depends on what you want to get out of the system and what your hybrid strategy is. How many cycles you get during the race or in a season.”
The vastly different demands of the varying classes where KERS can be used is one of the major reasons for Bosch’s modular approach, “for a 24 race application where you want to store energy at every braking event and release it immediately afterwards, like you would at Le Mans the demand are different to Formula 1 with its regulations” explains Wildner. “Around the Le Mans circuit I think you have 17 points where you brake and eight opportunities to use the boost around the lap. During the race that totals thousands of charging and discharging cycles. In Formula 1 the regulations state that you can only have one cycle per lap, no more than 78 cycles (the number of laps at Monaco). So in one world you have around 5,000 cycles per race and in the other you have just 78. So we developed this system to suit the different demands.”

[gwyllion]

According to http://www.motorsport.com/news/article.asp?ID=372283 the Porsche GT3 R Hybrid will compete in Petit Le Mans as a non-classified participant.

[Spyderman]

Yes, this has been reported some time ago. Thanks anyway.

[gwyllion]

Okay, I must have missed that.

The article also suggests that the ACO is unlikely to adapt hybrids in GT2, because their focus is on cost reduction and production engines.

[Spyderman]

I suspect that this is known by Porsche. The 997R Hybrid is really just a rolling Lab.