Kinetic Energy Recovery System (KERS)

Kinetic Energy Recovery System (KERS)
A system that is designed to recover kinetic energy from the car during braking, store that energy and make it available to propel the car.

Formula 1 is set for dramatic change with the introduction of new rules which permit the use of energy recovery systems from 2009. The goal is to make Formula 1 more relevant to the latest developments in energy-efficient road car engineering by promoting technologies to recover the energy currently wasted during braking.

Zytek have won a two year contract to develop and supply KERS for the 2009 season, when the regulations permitting the use of hybrid auxiliary drives become effective. Zytek had discussions with a number of F1 teams but finally agreed an exclusive deal with one team. The programme is in three phases of development: Bench/dyno system, Mule car development, and culminates with the development of a fully ‘Race-ready’ system.

The new regulations pose significant engineering challenges and there are many options to store and use the energy, such as high speed flywheels, hydraulics, pneumatics or electric drives. The system must recover and store energy under braking, and then release the energy on command by the driver.

The new regulations offer engineers a technology ‘clean sheet’ with very few constraints. There are no weight restrictions for the system, although energy can only be captured or released at a maximum rate of 60 kW, and a maximum of 400 kJ can be stored in any one lap. KERS energy can, for example, be released during a period of acceleration, and its use may be particularly advantageous when exiting corners or for tricky overtaking manoeuvres.

With a short development timeframe before the introduction of KERS, Zytek are focussed on developing and delivering a competitive system for the 2009 F1 season.

KERS Rules for 2009:
The use of any device, other than the 2.4 litre, four stroke engine and one KERS, to power the car, is not permitted.

With the exception of one fully charged KERS, the total amount of recoverable energy stored on the car must not exceed 300kJ. Any which may be recovered at a rate greater than 2kW must not exceed 20kJ.

The maximum power, in or out, of any KERS must not exceed 60kW (81bhp). Energy released from the KERS may not exceed 400kJ in any one lap. Measurements will be taken at the connection to the rear wheel drive train.

Any KERS may only be capable of increasing the stored energy whilst the car is moving on the track. Release of power from any such system must remain under the complete control of the driver at all times the car is on the track.

Cars must be fitted with homologated sensors which provide all necessary signals to the SDR in order to verify the requirements above are being respected.

Any components required as part of a KERS will be controled by the SECU

So this is an ultra-hi-tech push-to-pass system?

I can already see them brake-test each others before the race in order to charge the thing...

J/K of course... but this seems a bit pointless to me.. is this supposed to make me want to buy a Prius or something?

is this supposed to make me want to buy a Prius or something?

Idea is that tech made in F1 can be transfered into road cars.

Thanks Andy, great thread and post.

A joule is a watt-second, so the maximum stored 300kJ is 5 seconds at 60kW.

The storage medium will be very interesting. Flywheels can be dangerous, if they get out of their cage, so the cage is heavy, that's about all I know. Can you/anyone say anything about hydraulics?

So what can be done with 60kW of energy (and the maximum allowable per lap)?
How much is it is real terms? Has anyone got some numbers on how much of a speed difference it would make to a car at 300kph, for example.
Is it serious stuff, or just negligible?

Originally posted by alfa1
So what can be done with 60kW of energy (and the maximum allowable per lap)?
How much is it is real terms? Has anyone got some numbers on how much of a speed difference it would make to a car at 300kph, for example.
Is it serious stuff, or just negligible?

The FIA has defined the amount of energy recovery at 400kJ per lap, giving the driver an extra 80bhp over a period of 6.67 seconds. Obviously the KERS systmes wont be 100% efficent, but 90% efficency is thought to be achieviable.

The current 2.4 V8 outputs around 740bhp give or take a little per team.

Originally posted by ATM_Andy
Kinetic Energy Recovery System (KERS)

The maximum power, in or out, of any KERS must not exceed 60kW (81bhp). Energy released from the KERS may not exceed 400kJ in any one lap.

I find these 'power units' really confusing.

According to this web-site, http://www.onlinecon....com/energy.htm 60 kilowatt hour = 80.461 horsepower hour.
That extra 80 horsepower would be a big help in getting past an opponent on the pit straight, (assuming you can get that extra 80 horsepower onto the pavement)
But, if the guy you are attempting to pass hits HIS "push to pass" (P2P) button on the same straight, then any potential advantage is nullified.
On a circuit where there is more than one 'overtaking straight', it would become a game of strategy, as to which straight to use your P2P button.

But, the same web-site says that 400 kilojoule = 0.149 horsepower hour.
And that's the maximum amount that you are allowed to release, in any one lap.... 0.149 horsepower hour is one helluvabig difference from 81 horsepower hour.

What gives ?


As far as energy storage is concerned, I'd think that a bank of large capacitors might be the best way to go.
Who knows?
The manufacturers will probably spend another billion dollars (collectively), to find out which system is best, just as they did with the "cost-cutting" 2.4 litre V8.

So much for saving money in the F1 series

Originally posted by undersquare
Thanks Andy, great thread and post.

A joule is a watt-second, so the maximum stored 300kJ is 5 seconds at 60kW.

The storage medium will be very interesting. Flywheels can be dangerous, if they get out of their cage, so the cage is heavy, that's about all I know. Can you/anyone say anything about hydraulics?

The Hydraulic KERS idea is to reuse the vehicle's kinetic energy by conducting pressurized hydraulic fluid into an accumulator during vehicle deceleration, and conducting the pressurized fluid back into the drive system during vehicle acceleration.

To be honest I don't think any teams will do this, but will go for with the electrical/hybrid or mechanical solution.

A Mechanical KERS by Torotrak:



The components within each variator include an input disc and an opposing output disc. Each disc is formed so that the gap created between the discs is ‘doughnut’ shaped; that is, the toroidal surfaces on each disc form the toroidal cavity.

Two or three rollers are located inside each toroidal cavity and are positioned so that the outer edge of each roller is in contact with the toroidal surfaces of the input disc and output disc.
As the input disc rotates, power is transferred via the rollers to the output disc, which rotates in the opposite direction to the input disc.

The angle of the roller determines the ratio of the Variator and therefore a change in the angle of the roller results in a change in the ratio. So, with the roller at a small radius (near the centre) on the input disc and at a large radius (near the edge) on the output disc the Variator produces a “low” ratio. Moving the roller across the discs to a large radius at the input disc and corresponding low radius at the output produces the “high” ratio and provides the full ratio sweep in a smooth, continuous manner.

The transfer of power through the contacting surfaces of the discs and rollers takes place via a microscopic film of specially developed long-molecule traction fluid. This fluid separates the rolling surfaces of the discs and rollers at their contact points.

The input and output discs are clamped together within each variator unit. The traction fluid in the contact points between the discs and rollers become highly viscous under this clamping pressure, increasing its ‘stickiness’ and creating an efficient mechanism for transferring power between the rotating discs and rollers.



“The variator weighs less than 5kg in these applications and provides a high level of mechanical efficiency, enabling the overall mass of the mechanical KERS systems to be minimised,” says Chris Greenwood, technology director at Torotrak. “This mechanical efficiency, combined with the variator’s ability to change ratio very rapidly, helps to optimise flywheel performance.”

Originally posted by Milt
I find these 'power units' really confusing.

According to this web-site, http://www.onlinecon....com/energy.htm 60 kilowatt hour = 80.461 horsepower hour.
That extra 80 horsepower would be a big help in getting past an opponent on the pit straight, (assuming you can get that extra 80 horsepower onto the pavement)
But, if the guy you are attempting to pass hits HIS "push to pass" (P2P) button on the same straight, then any potential advantage is nullified.
On a circuit where there is more than one 'overtaking straight', it would become a game of strategy, as to which straight to use your P2P button.

But, the same web-site says that 400 kilojoule = 0.149 horsepower hour.
And that's the maximum amount that you are allowed to release, in any one lap.... 0.149 horsepower hour is one helluvabig difference from 81 horsepower hour.

What gives ?


As far as energy storage is concerned, I'd think that a bank of large capacitors might be the best way to go.
Who knows?
The manufacturers will probably spend another billion dollars (collectively), to find out which system is best, just as they did with the "cost-cutting" 2.4 litre V8.

So much for saving money in the F1 series

Okay, horsepower and horsepower hour are different things, horsepower isn't actually a SI unit and isn’t used in engineering, but the definition usually quoted is 1 hp = 0.7457 kW, a kW is a kJ per second.

Oh and I think your right the electrical/hybrid KERS is the way the teams will go.

I hope this isn't a dumb question, but, here goes...

Since most of the braking force, (roughly 60% in a road car), is generated by the front wheels, how do they plan to get that energy into whatever energy storage device they decide to use ???

If they use a mechanical/hydraulic system, it would require driveshafts, gears, and pumps, attached to the front wheels.

If they go with electrical storage, (either Li-Ion batteries, or capacitors), then it requires a generator of some kind, at each wheel.

This sysytem is beginning to sound pretty complex, (and therefore expensive), but of course this 'development cost' won't be included in any "budget cap" designed to help out the privateers.

EDIT: Andy... Thanks for the clarification in your previous post, just above this one.

Originally posted by Milt
I hope this isn't a dumb question, but, here goes...

Since most of the braking force, (roughly 60% in a road car), is generated by the front wheels, how do they plan to get that energy into whatever energy storage device they decide to use ???

If they use a mechanical/hydraulic system, it would require driveshafts, gears, and pumps, attached to the front wheels.

If they go with electrical storage, (either Li-Ion batteries, or capacitors), then it requires a generator of some kind, at each wheel.

This sysytem is beginning to sound pretty complex, (and therefore expensive), but of course this 'development cost' won't be included in any "budget cap" designed to help out the privateers.

EDIT: Andy... Thanks for the clarification in your previous post, just above this one.

Hi Milt, your quite correct most of the breaking is done at the front, however KERS will all be at the rear end for a number of reasons.

Originally posted by alfa1
So what can be done with 60kW of energy (and the maximum allowable per lap)?

60 kW is not a unit of energy! 400 kilo Joules is the max amount of energy!

Power is the transfer rate of energy.

Obviously 400 kilo Joules dispensed at 60 kilo Joules per second, can effectly provide the maximum 60 kW[=60 k(J per second)=60 k(Watts)] (or 81 horsepower) boost for 6.7 seconds per lap, or a smaller power boost for a longer time.

[ And obviously Power = Force x Velocity so for the same drag a car with more power (capacity to transfer fuel chemical energy and KRS energy into useful work at X % efficiency) will go faster.]



Of course the system is complex. But Fred's taxi cab Alfa super sedan won't be sprouting winglets any time soon will it! Time for some practical use apart from flappy paddle gearboxes eh?

Originally posted by Milt
But, the same web-site says that 400 kilojoule = 0.149 horsepower hour.
And that's the maximum amount that you are allowed to release, in any one lap.... 0.149 horsepower hour is one helluvabig difference from 81 horsepower hour.

That's if you release the 400 kilo Joules over 1 hour, hence the horsepower hour or kilowatt hour.

Note the ratio of horsepower hour to kilowatt hour, is to same as that of horsepower to kilowatts.

Kilowatt hour is a hokey unit!

As I understand it, only 300kJ can be stored at any one time, that's the "full charge".

Then there is a separate limit of 400kJ that can be generated for storage during one lap.

So if you "empty the tank" on one straight, recharge it, use it again, then you can only store another 100 kJ during the rest of the lap.

Originally posted by Milt
I find these 'power units' really confusing.

According to this web-site, http://www.onlinecon....com/energy.htm 60 kilowatt hour = 80.461 horsepower hour.
That extra 80 horsepower would be a big help in getting past an opponent on the pit straight, (assuming you can get that extra 80 horsepower onto the pavement)
But, if the guy you are attempting to pass hits HIS "push to pass" (P2P) button on the same straight, then any potential advantage is nullified.
On a circuit where there is more than one 'overtaking straight', it would become a game of strategy, as to which straight to use your P2P button.

But, the same web-site says that 400 kilojoule = 0.149 horsepower hour.
And that's the maximum amount that you are allowed to release, in any one lap.... 0.149 horsepower hour is one helluvabig difference from 81 horsepower hour.

What gives ?


As far as energy storage is concerned, I'd think that a bank of large capacitors might be the best way to go.
Who knows?
The manufacturers will probably spend another billion dollars (collectively), to find out which system is best, just as they did with the "cost-cutting" 2.4 litre V8.

So much for saving money in the F1 series

Would it be of much use on the straight? Once they are down the straight, and slipstreaming, I would have thought any push to pass would send them over the engine rev limit, unless the engine can be disconnected.

My mates been working on these for the past few months, he reckons its going to be awesome when they hit the track, ill see if he cant post what hes been working on

I didn't realise these things were coming out so soon!!!! Looks pretty cool thanks ATM-Andy...

Is the Hybrid one bascally the same thing they use on the Toyota Prius, or Lexus RX(thing)?

Honda are into "ultra capacitors"...

http://world.honda.c...ultracapacitor/



They are talking about their FCX fuel cell vehicle which also has capacitor-stored electricity as a backup power source. If I'm interpreting it correctly, the rate of energy conversion is more of a limitation than the storage capacity, and with this one they're saying 1 kg weight per 1.75 kW output, making 34.2 kg weight for 60kW.

Also the one in the car looks enormous, the full width of the back seat, though they dont' say what its capacity is that I can see.

So this is far more than the 5kg for the Torotrack variator that Andy described above.

Then there's the electric motor/generator...

I can actually see Max's plan to give this technology impetus working out.

Andy/engineers, can you guide us about the extra acceleration it will provide?

Anyone know who Zytek is rumoured to be supplying? It could definately help out a F1 team with another company doing all the R&D but I'd imagine most of the teams would like to do this in-house because each engine manufacturer has the resources to cope but also it would allow any innovations to filter to their road cars, if that's possible.

Jon Hilton of Flybrid, Adrian Moore of Xtrac and Dick Elsy of Torotrak with their compact flywheel and CVT variator for the KERS

The mechanical KERS system utilises flywheel technology developed by Flybrid Systems to recover and store a moving vehicle’s kinetic energy which is otherwise wasted when the vehicle is decelerated. The energy is received from the driveline through the Torotrak CVT, engineered and supplied by Xtrac, as the vehicle decelerates, and is subsequently released back into the driveline, again through the CVT, as the vehicle accelerates. The FIA has defined the amount of energy recovery for the 2009 season as 400kJ per lap giving the driver an extra 80hp over a period of 6.67 seconds.

Compared to the alternative of electrical-battery systems, the mechanical KERS system provides a significantly more compact, efficient, lighter and environmentally-friendly solution.

The components within each variator include an input disc and an opposing output disc. Each disc is formed so that the gap created between the discs is ‘doughnut’ shaped; that is, the toroidal surfaces on each disc form the toroidal cavity.

Two or three rollers are located inside each toroidal cavity and are positioned so that the outer edge of each roller is in contact with the toroidal surfaces of the input disc and output disc.

As the input disc rotates, power is transferred via the rollers to the output disc, which rotates in the opposite direction to the input disc.

The angle of the roller determines the ratio of the Variator and therefore a change in the angle of the roller results in a change in the ratio. So, with the roller at a small radius (near the centre) on the input disc and at a large radius (near the edge) on the output disc the Variator produces a “low” ratio. Moving the roller across the discs to a large radius at the input disc and corresponding low radius at the output produces the “high” ratio and provides the full ratio sweep in a smooth, continuous manner.

The transfer of power through the contacting surfaces of the discs and rollers takes place via a microscopic film of specially developed long-molecule traction fluid. This fluid separates the rolling surfaces of the discs and rollers at their contact points.

The input and output discs are clamped together within each variator unit. The traction fluid in the contact points between the discs and rollers become highly viscous under this clamping pressure, increasing its ’stickiness’ and creating an efficient mechanism for transferring power between the rotating discs and rollers.

The rules are idiotic, there shouldnt have been limits in the quest of efficiency and power. And the car engine, anyone should be able to make a tinier one.

Originally posted by Showty
Here it is.

I think thats just one (the mechanical) idea I think...

I thought to start with that the 5kg unit was just the variator/transmission, but I realise now it is the whole thing and one of the guys in Showty's pic is holding the flywheel. Obvious now . Some calculations from a formula at http://zebu.uoregon....1/ph162/l8.html show that even a plain disc flywheel of 4.3 kg/200mm dia running at 30,000 rpm would store the 300 kJ. I suppose it's not really all that much energy.

One advantage of the flywheel is that you can release the energy as fast as you like, unlike batteries or capacitors which have heat issues. If the Honda capacitors are anywhere near representative they don't look viable by comparison, unless they can be ballast as well, perhaps.

The energy stored is proportional to the square of the speed, so they are going to run the flywheels as fast as they possibly can. The limit seems to be the tensile strength of the flywheel material before it bursts apart. Presumably someone is going to be paying attention to safety...

All very interesting anyway. Even though it's not new technology it may make it trendy enough to get a start in road cars despite the cost. Another 80 bhp or whatever for overtaking can only be a good thing

For F1 racing, well IMO push-to-pass hasn't helped Champ Car, just another artificial kludge like the hard-and-soft tyres that makes it too contrived. Hope I'm wrong.

Originally posted by AlexS
The rules are idiotic, there shouldnt have been limits in the quest of efficiency and power.

I agree!
If the manufacturers are going to spend 10s of millions, (more likely 100s of millions), on developing this new technology, why not at least allow them to start with 'a clean sheet of paper' ?


And, the way the rules are currently set up, in that you have to "use it or lose it" on each lap, then every driver will use his P2P button just after the apex of the last corner leading onto the main pit straight.
And since everybody will be limited to 80.4 extra horsepower for 6.6 seconds, all the cars will still be equal down the straight, but the teams will need to use a slightly 'taller' final drive gear to prevent hitting the rev limiter.
I think the Champ Car system, of allotting a certain number of seconds that you can use your P2P during the whole race is better (I believe that it's a 60 second limit).
With that system, if you can 'save' your P2P boost until the last few laps, and the guy in front of you hasn't, then you have a legitimate "earned advantage" over him, and may be able to pull off the pass for position, regardless of whether it's for 1st or 8th place.


That flyweel settup looks like a good way to go!
But, it better be housed in a scattershield of some kind.
I've witnessed the carnage that a car flywheel can cause, at only 5 ~ 6,000 RPM... so 30,000 RPM sounds scary!

How should this affect the racing??

How should this affect the racing??

This and similar systems might prevent companies like Toyota from leaving F1.

I keep looking at the bit in the rules that says "Any which may be recovered at a rate greater than 2kW must not exceed 20kJ".

What does this mean? Does it mean that there can be a small buffer of 20kJ, then after that the KERS can only be recharged at a maximum rate of 2kW?

If so, it will take 30 seconds of braking (+ losses) to recharge. That is a number of laps.

That might be the answer to Milt's point that if it charged at 60kW all the drivers would use it every lap, probably at the same place.

If this is right then once a driver has used up his KERS he's a sitting duck if someone else can close up in the next few laps.

So the tactics could get quite interesting.

Originally posted by undersquare
I keep looking at the bit in the rules that says "Any which may be recovered at a rate greater than 2kW must not exceed 20kJ".

They are talking bout the other, regular, batteries aren't they

Originally posted by undersquare
I keep looking at the bit in the rules that says "Any which may be recovered at a rate greater than 2kW must not exceed 20kJ".


What does this mean? Does it mean that there can be a small buffer of 20kJ, then after that the KERS can only be recharged at a maximum rate of 2kW?

If so, it will take 30 seconds of braking (+ losses) to recharge. That is a number of laps.

That might be the answer to Milt's point that if it charged at 60kW all the drivers would use it every lap, probably at the same place.

If this is right then once a driver has used up his KERS he's a sitting duck if someone else can close up in the next few laps.

So the tactics could get quite interesting.

30 seconds of breaking to charge the thing, that makes sense, but that mens that the KERS will be a lot more use at say monacco than monza where there is a lot more breaking.

ATM-Andy did say "With the exception of one fully charged KERS" though, does this mean other recoverable energy???

Do the cars allready have a native ammount of recoverable on them form the engine flywheels/suspention etc??

I was wrong about the 30 seconds, to generate 300kJ it needs either 150 seconds at 2kW or 5 seconds at 60kW. With say 10-12 seconds braking per lap neither of those seems right, a recharge is either half a lap or 13 laps.

Originally posted by AlexS
The rules are idiotic, there shouldnt have been limits in the quest of efficiency and power. And the car engine, anyone should be able to make a tinier one.

From the racing perspective, it's true.

But the specs for the unit (60kW for 6 seconds of power) are perfect for a normal road car.

Originally posted by CaptnMark


From the racing perspective, it's true.

But the specs for the unit (60kW for 6 seconds of power) are perfect for a normal road car.

Exactly right. Say, 7 seconds 0-62 and 65 mpg - having your cake and eating it .

But I wonder, will it in fact be an F1 manufacturer who first does it? Or another one who by not doing F1 has an extra $500m or so to spend on it?

Originally posted by AlexS
The rules are idiotic, there shouldnt have been limits in the quest of efficiency and power. And the car engine, anyone should be able to make a tinier one.

Yeah. But if there wasnt a limit, the alternative power source could be the primary way to move the car and gain more performance without saving energy.

I think it would be impressive to have V8 going full revs all the time, producing as much energy as possible. And the car be accelerated by an electric motor.

Yeah. But if there wasnt a limit, the alternative power source could be the primary way to move the car and gain more performance without saving energy.

I mean the KERS shouldnt have a limit. Obviously the engine should but i would have prefered a fuel limit. I always tought that the best system to curtail performance was decreasing the fuel. No X Y or Z cylinder no cm3, no to the overegulation that makes bureaucrats happy and ideas stall. My F1 would have dimension rules and a fuel limit. Engines well everyone could put what they want. Performances increase too much well just slash a bit of fuel.

Originally posted by Milt
I agree!
If the manufacturers are going to spend 10s of millions, (more likely 100s of millions), on developing this new technology, why not at least allow them to start with 'a clean sheet of paper' ?


And, the way the rules are currently set up, in that you have to "use it or lose it" on each lap, then every driver will use his P2P button just after the apex of the last corner leading onto the main pit straight.

I agree that its ridiculous limiting the capacity and power - but F1 is now barely a development class.

There is an alternative strategy though - go the same speed as before, and save fuel, hence extending your range.

I'd have also thought that using the power in early acceleration might be more efficient since you are not pushing as much wind resistance? If you get the car up to speed earlier, then you carry that extra speed for a longer time. So using it for all of the main straight might not be the best use of it. Certainly coming out of the corner before the main straight, if there is enough grip, sounds good. But maybe also use it for the beginning of the short straights as well.

As I understand the rule a car can store 300kj of energy in its various systems - battery, pneumatic valve air supply, pressurised accumulators, etc. Anything that can store power in the car, except the gas. They limit the rate at which it can be drawn from large storage sources so some clever engineer doesn't use it to propel the car.

the 400kj in the KERS is in addition to this.

Originally posted by tomspar
As I understand the rule a car can store 300kj of energy in its various systems - battery, pneumatic valve air supply, pressurised accumulators, etc. Anything that can store power in the car, except the gas. They limit the rate at which it can be drawn from large storage sources so some clever engineer doesn't use it to propel the car.

the 400kj in the KERS is in addition to this.

Ah, thanks, that makes a bit more sense now.

I've just seen Jon Hilton of Flybrid being interviewed at the Autosport show. He gave these stats for their KERS...

Flywheel weight 5kg
Overall weight 24 kg
Fywheel speed 64,500 rpm
Energy storage 580 kJ, he described it as "an 80 hp device" - presumably after losses.

The flywheel is contained in a casing, of course, but if it did break up it would be like a small bomb going off. The whole thing may be small in road car terms, but it looks like packaging it in an F1 car will take some doing.

Originally posted by Melbourne Park


I agree that its ridiculous limiting the capacity and power - but F1 is now barely a development class.

There is an alternative strategy though - go the same speed as before, and save fuel, hence extending your range.

I'd have also thought that using the power in early acceleration might be more efficient since you are not pushing as much wind resistance? If you get the car up to speed earlier, then you carry that extra speed for a longer time. So using it for all of the main straight might not be the best use of it. Certainly coming out of the corner before the main straight, if there is enough grip, sounds good. But maybe also use it for the beginning of the short straights as well.

I think the tactics will be very interesting, if we know what's going on. I'm sure you're right the "area under the curve" approach using it early on the straight rather than later will be the best way to do it.

Also on tracks where the start/finish line is half way down a long straight, say, if a driver is behind someone and can draft them enough to save some kers, on the next drive down the straight if his kers has enough capacity he can use up to 800 kJ - 400 on the first half of the straight and 400 on the second.

Originally posted by undersquare
The flywheel is contained in a casing, of course, but if it did break up it would be like a small bomb going off. The whole thing may be small in road car terms, but it looks like packaging it in an F1 car will take some doing.

That is the ironic issue with the KERS program for F1 - the FIA have not made it an R&D exercise in energy recovery because they have limited the capacity of the KERS. Instead, the FIA has shifted the competitive advantage into how neatly the KERS is packaged in the weight and aero sensitive F1 cars. Which are completely difference to road cars, which require aero efficiency only at high speed. And KERS devices are useful only on city cars, which have no need for efficient aerodynamics.

If the FIA had said you can recover as much power as you choose, then we'd see some beneficial R&D which might feed into road cars. And it would have been be fun to compare the system differences.

One might wonder though, if the rotating mass of such a device was also used for stability benefits, the gyro forces of a rotating mass could have some side benefits.

Originally posted by undersquare


I think the tactics will be very interesting, if we know what's going on. I'm sure you're right the "area under the curve" approach using it early on the straight rather than later will be the best way to do it.

Also on tracks where the start/finish line is half way down a long straight, say, if a driver is behind someone and can draft them enough to save some kers, on the next drive down the straight if his kers has enough capacity he can use up to 800 kJ - 400 on the first half of the straight and 400 on the second.

Of course if a car doesn't use its KERS system because its faster than the car in front, then it could use it on the main straight in order to overtake. Unfortunately IMO if the system had not been limited by the rules, it would have been possible for a slightly faster car to store up say three laps of energy recovery, and then use all the power in one big hit on the main straight in order to overtake! That was what the scheme originally was about I thought. But by limiting its capacity so much, such a tactic won't be able to be used. I don't get what the FIA is trying to achieve.

Originally posted by Melbourne Park
That is the ironic issue with the KERS program for F1 - the FIA have not made it an R&D exercise in energy recovery because they have limited the capacity of the KERS. Instead, the FIA has shifted the competitive advantage into how neatly the KERS is packaged in the weight and aero sensitive F1 cars. Which are completely difference to road cars, which require aero efficiency only at high speed. And KERS devices are useful only on city cars, which have no need for efficient aerodynamics.

If the FIA had said you can recover as much power as you choose, then we'd see some beneficial R&D which might feed into road cars. And it would have been be fun to compare the system differences.

One might wonder though, if the rotating mass of such a device was also used for stability benefits, the gyro forces of a rotating mass could have some side benefits.

That's right they have almost said "use existing technology". With 2009 car design already under way there's been no time for anything else. F1's role, though Max can't say it, is just to make KERS cool so the early adopters will pay extra for it.

I think kers in road cars could be useful across the board, in a high performance car you can always use another 80 bhp. Or hey, use two 5kg flywheels for 160 . Especially with the European rule they're talking about where a manufacturer's entire range of cars has to average under a certain CO2 limit - BMW and Merc are sweating.

Originally posted by Melbourne Park


One might wonder though, if the rotating mass of such a device was also used for stability benefits, the gyro forces of a rotating mass could have some side benefits.

Interesting! I had been wondering if the gyro effect might be a problem, but that's negative thinking unworthy of F1 . Do you suppose Renault are powering a flywheel by electricity and putting it in the nose?

Originally posted by undersquare


Interesting! I had been wondering if the gyro effect might be a problem, but that's negative thinking unworthy of F1 . Do you suppose Renault are powering a flywheel by electricity and putting it in the nose?

they must be checking their McLaren drawings!

I cannot see why some innovation could not use some of the inertia to benefit the car in some other way - by "accident" of course. Since the FIA has limited the use of the device, F1 engineers would naturally look for other uses for it. If there was no limit to the systems capacity, engineers would focus on efficiently recovering as much available power as there was. But since the FIA has outlawed that, they'll look for something extra in another area IMO.

Originally posted by Melbourne Park
One might wonder though, if the rotating mass of such a device was also used for stability benefits, the gyro forces of a rotating mass could have some side benefits.

I was actually wondering how much the thing weighed.
Surely a team could be 1 second a lap faster than a competitor using such a system, simply by not having any heavy system installed at all.

I also wonder the same about on board electronics.
One online source says an F1 car has a mile of wiring, and 120 sensors. Plus of course all those boxes containing the smarts to run it all. I can see the point of having it all during testing and friday practise, but I wonder about the massive weight saving that could be achieved by running the car without most of it during a race.

Originally posted by alfa1


I was actually wondering how much the thing weighed.
Surely a team could be 1 second a lap faster than a competitor using such a system, simply by not having any heavy system installed at all.

I also wonder the same about on board electronics.
One online source says an F1 car has a mile of wiring, and 120 sensors. Plus of course all those boxes containing the smarts to run it all. I can see the point of having it all during testing and friday practise, but I wonder about the massive weight saving that could be achieved by running the car without most of it during a race.

It's more an issue of having higher centre of gravity, because having a KERS device would result in having less ballast, and ballast is usually put as low as possible ( Renault's TMD wasn't though, but then they said it was a damper and was not moving ballast). But a low CofG results in flatter cornering, everything else being equal. A rotating device higher up in the car might also provide flatter cornering, or less dive under brakes, than having ballast mounted at the lowest point in the car. Who knows?

Originally posted by alfa1


I was actually wondering how much the thing weighed.
Surely a team could be 1 second a lap faster than a competitor using such a system, simply by not having any heavy system installed at all.

I also wonder the same about on board electronics.
One online source says an F1 car has a mile of wiring, and 120 sensors. Plus of course all those boxes containing the smarts to run it all. I can see the point of having it all during testing and friday practise, but I wonder about the massive weight saving that could be achieved by running the car without most of it during a race.

I imagine they'll still have to meet the 605 kg minimum car+driver weight, as MP says swapping ballast for the KERS.

The bulk though is a factor, I had also been wondering if KERS might make the car slower over a lap. Looking at the Flybrid pics and the scale in relation to the guys' hands, it looks something like 200mm diameter (with the casing) and 250 long. Maybe a bit more.

Where is that going to go? Alongside the engine? Apart from raising the CoG, it's going to make a big difference to the aero. I wonder if this is why Zytec only got one team to sign up, maybe it's Force India, with the bigger (and customer) teams working on more aero-friendly systems.

The capacitor system looks better in this light, and now we know the Zytec weighs 24 kg, the capacitor weight looks more competitive, especially with some development.

There's a good discussion of it at http://www.theengine...rvival race.htm

Among other things the article says the big teams will be developing both technologies simultaneously, including the "flywheel battery" in which a flywheel stores the energy but is connected to the transmission electrically.

Toyota is quoted saying that a well-integrated KERS could reduce lap time by about 0.4 seconds.

Originally posted by undersquare
Toyota is quoted saying that a well-integrated KERS could reduce lap time by about 0.4 seconds.

If that's all the advantage it gives over a lap, it doesnt sound like it will produce much in the way of overtaking oppurtunities.

Originally posted by undersquare


I imagine they'll still have to meet the 605 kg minimum car+driver weight, as MP says swapping ballast for the KERS.

The bulk though is a factor, I had also been wondering if KERS might make the car slower over a lap. Looking at the Flybrid pics and the scale in relation to the guys' hands, it looks something like 200mm diameter (with the casing) and 250 long. Maybe a bit more.

Where is that going to go? Alongside the engine? Apart from raising the CoG, it's going to make a big difference to the aero. I wonder if this is why Zytec only got one team to sign up, maybe it's Force India, with the bigger (and customer) teams working on more aero-friendly systems.

The capacitor system looks better in this light, and now we know the Zytec weighs 24 kg, the capacitor weight looks more competitive, especially with some development.

There's a good discussion of it at http://www.theengine...rvival race.htm

Among other things the article says the big teams will be developing both technologies simultaneously, including the "flywheel battery" in which a flywheel stores the energy but is connected to the transmission electrically.

Toyota is quoted saying that a well-integrated KERS could reduce lap time by about 0.4 seconds.

I was wandering where it would go too...

I think the electrical KERS would be easied to package (in the engine cover??) as the Flybrid looks like it would be big and lumpy on top of the gearbox!!