RACING WITH HYBRIDSPROPOSAL TO THE ESMSC

Jean Jacques His, Ferrari Head of Powertrain Department16/11/2010

This presentation has been prepared and discussed

by the Powertrain Group, and then presented to the

Environmentally Sustainable Motorsport Commission.

However, this work is still in progress.

This presentation has not yet got the final approval

from the ESMSC.

Hybrids, KERS…Definitions & General Comments

Hybrid powertrains :- In this paper, hybrid powertrains are any kind of powertrain in which instant

power may come from different sources, one of them being an internal

combustion engine.

- Primary energy on board the vehicle comes from a single energy source (ie : one

single fuel is supplied to one single reservoir).

- Secondary power source(s) use energy which has been recovered and stored in

some accumulator (electric, pneumatic, flywheel or else..) while the car is

running.

Kinetic Energy Recovery System :- In this system, the energy recovered and stored in the accumulator is only kinetic

energy. Recovery takes place only when slowing down / braking.

Impact of Hybrid Powertrains On fuel economy

Hybrid powertrains in homologation cycle :- Engine is used at very low load : high mechanical + pumping losses

- Energy use ≈ 35 % inertia / 45 % rolling + aerodynamic + resistence / 20 %

gearbox & ancillaries

- Stop & Start : cut idle operation (≈ 10 % of fuel used in EU cycle)

- Efficiency : best ≈ 35 % (240 g/KW.h); city conditions (low BMEP) < 20 % ! Major improvements : Load Point Moving + pure electric drive in city cycle

- Brake energy recovery is an additional benefit of the device Improvement of homologated fuel economy with hybrid systems may reach ≈

30 % on powerful premium which run at very low BMEP in the homologation

cycle.

General use on the road :- On high speed / motorway, potential improvement with hybrid systems is much

lower / ≈ zero (internal combustion engine is then used in optimum conditions)

- Hybrid system (secondary power source) may be used as a booster

Load point moving Best engine efficiency achieved at ≈ full load (case below ≈ 14 bar BMEP / 3000

rpm)

In most low speed or steady state conditions, engines are run at >> 350 g/kWh.

increase BMEP : Energy Storage & Recovery Systems are the most radical

solution !

Potential impact of KERS On fuel economy in race conditions

Racing with Kinetic Energy Recovery System, a best case from some basic assumptions :- perfect recovery system- no limitation on torque applied by KERS during braking- no limitation on electric motor duty cycle- car speed profile supposed to be same w / wo KERS fuel saving proportional to the energy which has been recovered by KERS, fully independent of the thermal engineRealistic assumptions would probably lead to ≈ 50 to 60 % of expected fuel savings below

Single seaterAverage circuit

Braking / lap time (typical lap : 90 sec, brakes on : 17 sec) 16%

Braking power recovery (kW) 60

Kinetic Energy Recovery System overall efficiency 100%

Engine + gearbox overall efficiency 31%

Average power recovery from KERS (kW) 9,6

If above power would have to be supplied by ICE engine, this power would increase fuel consumption by (l/h) ……………… 3,40

Potential impact of KERSOn fuel economy in race conditions

Conclusion : a perfect 60 kW Kinetic Energy Recovery System, with 100 %

efficiency, would recover < 10 kW average power, equivalent to 3,4

l/hour of fuel a perfect 60 kW Kinetic Energy Recovery System, with 100 %

efficiency, would recover < 3 % of the energy provided by a current F1

engine in the same conditions for the same lap time, a perfect 60 kW Kinetic Energy Recovery

System, with no energy storage limitation, would provide less than 3 %

of fuel consumption improvement on a current F1 car. real world situation, with real world 60 kW KERS (not a perfect

system), would provide less than 1,5 % fuel consumption improvement

with same ICE engine for the same lap time.

Impact of Hybrid PowertrainsOn fuel economy

Potential performance of a “perfect” KERS system, three options :

-If speed profile is left free, for same car and engine, adding a KERS will

just improve performance and will not significantly change fuel

consumption

-If speed profile is left free, if Load Point Moving is allowed, engine

average load will be increased and a perfect KERS system would

improve performance but fuel consumption will increase … even if

efficiency (BSFC) is improved.

-If speed profile is kept the same, for a race track having 16 % of lap time

spent with brakes on, a perfect KERS would save ≈ 0,06 l/hour of fuel per

kW of KERS (3,4 litres / hour saved by a perfect 60 kW KERS…

whatever the engine).

Would racing with hybrids help hybrids?

Main challenges for road hybrids, focus on : low speed operation- Load Point Moving & Electric Drive

- Cut the cost

- Cut the weight : improve specific energy of energy storage systems

- Improve components efficiency

Main challenges for race hybrids, focus on : high speed operation- Booster

- Weight : improve electric motor & energy storage system power to weight ratio

- Improve components efficiency

- Vehicle dynamics control when KERS is working

- Cost of development

- Cost of components (control the use of “exotic” materials)

- Crash safety

synergies between racing and mainstream industry would benefit to the

development of hybrid systems components

Racing with hybrids?

Racing with hybrids would mean :

- for given car + engine configuration : speed profile defines power

requirement. Race engine already working at full load, ie : best

efficiency

- extra power from KERS : booster, on top of engine power : improved

performance for “same” fuel consumption (overtaking …)

- fuel consumption to be improved only by substitution of ICE energy

with lost energy recovery (braking, thermal losses..) : electric drive in pit

lane ??

- 4WD potential with some systems (electric front axle)

- vehicle dynamic control to be adressed (balance during braking)

- increase of cost and weight

Racing with hybrids In top level categories

Manufacturer competition :

- Racing with hybrids would help improving energy storage and motors (electric or

else ..) technologies

- Risk : development of exotic technologies

Would race hybrids be worth their cost :

- Would racing with hybrid help the development of energy storage systems, which

has been going strongly up to now with industrial competition ?

- What impact on racing ? …. overtaking (KERS), pit lane with electric drive, …

What racing with hybrids would mean :

- Racing technologies would remain (more) consistent with road going

technologies

- We have to understand whether electric drive to front wheels might be

acceptable

- We have to understand whether motorsport needs hybrids …..

- ….. and whether hybrid technology needs motorsport.

Privateers racing with hybrids?

Privateers racing with hybrids :

- Sports & GT road cars with hybrid powertrains are coming on the

market

- Hybrid cars should be homologated

Critical issues :

- Safety

- Cost (keep SoC of batteries at an acceptable level…)

- Control strategies (recover braking energy only, or accept LPM, driving

aids ….)

- Power : air restrictors control maximum ICE power, adding a booster

might be conflicting with instant power control

GT racing :

- GT racing has to face the hybrid issue

- Current GT racing open to 2WD only

Next Stepswith Hybrids?

Racing with hybrids :- Accept a limited improvement of fuel economy in race conditions ?

- A solution targeting higher FE improvement in race remains to be found

- Use recovered enegy for overtaking ?

- Electric drive : use recovered energy in pit lane ??

- Accept 4WD in categories which do not allow it up to now ???

- Would hybrid cars be competitive against conventional cars ??

- … and would all this be worth the money ?

Top level racing : - KERS currently investigated for F1

GT racing :- Save consistency and relevance with production cars

- Define technical rules

- Define homologation rules