KERS question

[Nando]

Is it possible to drive the car forward without any use of throttle, just KERS?

If yes, was thinking about the starts and if it was possible to run the initial phase of the getaway on pure KERS?
If no, assume yes, would it be of any benefit?

I´m mainly thinking of the torque delivery of electric engines.

[Tim.Wright]

I don't think they allowed to use KERS at low speed otherwise its too difficult to police possible traction control algorithms in the KERS motor control.

Anyway, since you are traction limited, it shouldn't really make much of a difference in performance whether the torque comes from KERS or the engine

[xxChrisxx]

Having maximum Emotor torque availalble at 0rpm means you can run a longer first gear. But I suppose having a seamless upshifting box makes this a moot point. It's also easier to modulate emotor output.

It would also mean you can rid yourself of an external starter.

[Lycoming]

I think using just KERS you could actually be power limited at launch.

[Dragonfly]

There is a speed threshold above which KERS can be used - IIRC 100 km/h but not sure. Just to prevent using it as a launch aid.
Also the tech regulations postulate that the main clutch must disengage the engine and the KERS from the transmission.

[autogyro]

Interesting, so what if the powertrain has no clutch and the KERS system is also the gearbox?

[Nando]

It's also easier to modulate emotor output.

This was what i thought as well.
Just that first 1,5m to get the car running.

Torque output according to Wiki is around 18 Nm. Perhaps it´s not enough to do somethihng with regardless of rules.

[Tommy Cookers]

Having maximum Emotor torque availalble at 0rpm means you can run a longer first gear.

the maximum torque is, in principle, independent of rpm
it is basically dependent on the current going through the motor

it is better in many ways to avoid using the motor so that it gives highest torque at zero rpm
AFAIK they don't do it, the motor drive isn't sized to allow such 'unlimited' current

[andylaurence]

Aside from the rules, there's a few reasons why it's not a good idea to run the car on KERS alone from standstill.

Firstly, it's only 80bhp (160bhp in 2014) and spins with the engine. As such, it's geared for a high speed in first gear and will therefore be pretty slow. Imagine drag racing against an F1 car in a Caterham and deciding to launch in 3rd gear to give the F1 car a chance!

Secondly, I'm guessing that the motors are brushless units. In order to get the power to weight I've seen quoted, they're probably going to have pretty low resistance. This means that they will flow a lot of current at low speed as there's nothing to stop it. That'll cook controllers in nanoseconds as huge currents flow through. They work better at higher speeds as the current reduces, easing the load on the controller. That KERS only gets used at about the top 20% of the rev range is of benefit when making small motors and controllers that don't go pop.

[autogyro]

Using the KERS system to drive the car from stationary was part of the original thinking for developing alternate energy use in F1.
It included the use of electric drive only in the pits, this has now been delayed.
I advised the FIA on this whole concept some years ago.
Since then KERS has been limited by regulation and the over all technology has been limited almost completely by the continued use of the old fashioned layshaft stepped gearbox.
It is possible to develop an alternate system that would allow the use of electric power from stationary within the regulations as they are and to include workable electric traction in the pits.
Unfortunately at this time in vehicle engineering history, the cost of such development cannot guarantee that the regulations would not be changed if there was any chance of F1 loseing the 'shock and awe' image it promotes to delude the world for the sake of continued fossil fuel use.
With the economic climate as it is and the need of motor manufacturers to prevent the rapid uptake of electric traction for obvious reasons, no F1 powertrain manufacturer is going to be willing to do anything other than follow the status quo and retain the old technology.

IMO the 2014 regulation (if they ever arrive) will also be diluted way beyond encouraging any meaningful development.