When does an F1 car's rear light flash?

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Tommy Cookers
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Joined: 17 Feb 2012, 16:55

When does an F1 car's rear light flash?

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maybe this is now clear to everyone except me
what does the red flashing light before braking mean ?

(a) 120 kW or some other kW of K motor action is absent
(b) 120 kW or some other kW of K generator action is present
(c) both of the above

restless
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Joined: 10 May 2016, 09:12

Re: Honda Power Unit

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It will aslo flash if the driver lift off the gas pedal

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dren
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Joined: 03 Mar 2010, 14:14

Re: Honda Power Unit

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Tommy Cookers wrote:
16 Nov 2017, 14:39
maybe this is now clear to everyone except me
what does the red flashing light before braking mean ?

(a) 120 kW or some other kW of K motor action is absent
(b) 120 kW or some other kW of K generator action is present
(c) both of the above
I thought it was (b).
Honda!

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MrPotatoHead
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Joined: 20 Apr 2017, 19:03
Location: All over.

Re: Honda Power Unit

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Tommy Cookers wrote:
16 Nov 2017, 14:39
maybe this is now clear to everyone except me
what does the red flashing light before braking mean ?

(a) 120 kW or some other kW of K motor action is absent
(b) 120 kW or some other kW of K generator action is present
(c) both of the above
Flashes when storage depleted / K recovering was my understanding.

daren_p
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Joined: 28 Aug 2016, 23:58

Re: Honda Power Unit

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restless wrote:
16 Nov 2017, 14:56
It will aslo flash if the driver lift off the gas pedal
I don't believe this to be the case. As posted I believe it is to warn other drivers the car in front has lost battery/electric assist. This is because it could happen in a location where drivers don't normally let off/brake, so it warns them the car in front could be slowing substantially in a location that isn't normal.

ArcticWolfie
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Joined: 23 Jun 2017, 18:37

Re: Honda Power Unit

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daren_p wrote:
16 Nov 2017, 17:26
restless wrote:
16 Nov 2017, 14:56
It will aslo flash if the driver lift off the gas pedal
I don't believe this to be the case. As posted I believe it is to warn other drivers the car in front has lost battery/electric assist. This is because it could happen in a location where drivers don't normally let off/brake, so it warns them the car in front could be slowing substantially in a location that isn't normal.
During a dry race the red light flashes when the ERS is charging due to lift & coast.

During a rain race the red light flashes continuously (or always on... difficult to see because of the LED refreshrate) to notify/warn drivers that there's a car driving there :P

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etusch
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Re: Honda Power Unit

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daren_p wrote:
16 Nov 2017, 17:26
restless wrote:
16 Nov 2017, 14:56
It will aslo flash if the driver lift off the gas pedal
I don't believe this to be the case. As posted I believe it is to warn other drivers the car in front has lost battery/electric assist. This is because it could happen in a location where drivers don't normally let off/brake, so it warns them the car in front could be slowing substantially in a location that isn't normal.
As deployment something programmed for every track and every part of the track, in normal condition, when it flash it's normal

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bigblue
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Joined: 01 Oct 2014, 12:18

Re: Honda Power Unit

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I asked this question a little while ago here (or maybe on autosport forums, I forget). I expected to get a load of "you don't even know that !" responses, but didn't, which was good ... and bad - it seems it's not exactly clear to many, as to what it means.

Best I can do to shed some light on things is this :
‘Lift and coast’

If the torque management system on the car decides to go into a fuel-save mode, the rear light will flash for a second to warn any driver behind. The thresholds are configurable but currently set for a car above 95 per cent throttle for more than a second, travelling faster than 180kph, that experiences a torque reduction of 120kW or more.

The warning system has been created because these events are controlled by the electronics rather than by the driver. If the driver decides to back off early then the situation is as it always has been. He has a responsibility to ensure another car is not close behind him. It’s as simple as that. One would normally expect the driver to check that it’s OK to back off. The warning light is there for situations not controlled by the driver.
Don't know if this the only circumstance, and if still exactly correct (since the link says '2014') but it's from the FIA website (https://www.fia.com/news/f1-race-direct ... l-briefing)

NL_Fer
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Re: Honda Power Unit

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restless wrote:
16 Nov 2017, 14:56
It will aslo flash if the driver lift off the gas pedal
If the torque management system on the car decides to go into a fuel-save mode, the rear light will flash for a second to warn any driver behind. The thresholds are configurable but currently set for a car above 95 per cent throttle for more than a second, travelling faster than 180kph, that experiences a torque reduction of 120kW or more.

The warning system has been created because these events are controlled by the electronics rather than by the driver. If the driver decides to back off early then the situation is as it always has been. He has a responsibility to ensure another car is not close behind him. It’s as simple as that. One would normally expect the driver to check that it’s OK to back off. The warning light is there for situations not controlled by the driver.
This is how they wrote about in 2014 during a drivers briefing. Funny they say fuel-save, because most of he time the torque reduction is caused by the MGU-K shutting off.

OO7
OO7
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Re: When does an F1 car's rear light flash?

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Also I think the rate of flashing is variable depending on how much harvesting/de-rating is occurring.

Nickel
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Location: London Mountain, BC

Re: Honda Power Unit

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NL_Fer wrote:
16 Nov 2017, 19:11
restless wrote:
16 Nov 2017, 14:56
It will aslo flash if the driver lift off the gas pedal
If the torque management system on the car decides to go into a fuel-save mode, the rear light will flash for a second to warn any driver behind. The thresholds are configurable but currently set for a car above 95 per cent throttle for more than a second, travelling faster than 180kph, that experiences a torque reduction of 120kW or more.

The warning system has been created because these events are controlled by the electronics rather than by the driver. If the driver decides to back off early then the situation is as it always has been. He has a responsibility to ensure another car is not close behind him. It’s as simple as that. One would normally expect the driver to check that it’s OK to back off. The warning light is there for situations not controlled by the driver.
This is how they wrote about in 2014 during a drivers briefing. Funny they say fuel-save, because most of he time the torque reduction is caused by the MGU-K shutting off.
Not necessarily. Don't underestimate the complexity of these units. Any time the engine experiences a torque reduction of 120kw+ can mean many things. Ex:Mguh can feed directly to the K for the first half of a strait, then starts aggressively charging the battery, providing ~70kw less to the K. Increased harvesting adds backpressure to the ICE, robbing it of another 15kw. Engine then reduces fuel consumption through pre programming and robs it of another 35kw. Now we're at 120, and the mguk is still providing 50kw of electrical generation.

All hypothetical and could be out to lunch, but I think people are trying to associate the flashing light with a specific engine behavior and I think that's completely wrong. It means what the rules say it means. 120+kw torque reduction independent of driver inputs.

Moose
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Joined: 03 Oct 2014, 19:41

Re: When does an F1 car's rear light flash?

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Interestingly, the rules don't specify. I just trawled through both the technical regulations and the sporting regulations, and no where do the rules specify what the light must do.

I found only two references to the rear light, one in the technical regulations (14.5) specifying where it needs to be placed, and one in the sporting regulations (22.12) specifying that it has to be on during rain.

AJI
AJI
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Re: When does an F1 car's rear light flash?

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Tommy Cookers wrote:
16 Nov 2017, 14:39

(a) 120 kW or some other kW of K motor action is absent
(b) 120 kW or some other kW of K generator action is present
(c) both of the above
Interesting. I always assumed it was (a), mainly from the 2016 Spanish GP. Ham clearly gains on Ros when his rear light flashes just before they crash and they're both still accelerating.

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Craigy
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Joined: 10 Nov 2009, 10:20

Re: When does an F1 car's rear light flash?

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Moose wrote:
21 Nov 2017, 06:44
Interestingly, the rules don't specify. I just trawled through both the technical regulations and the sporting regulations, and no where do the rules specify what the light must do.

I found only two references to the rear light, one in the technical regulations (14.5) specifying where it needs to be placed, and one in the sporting regulations (22.12) specifying that it has to be on during rain.
When they flash:
"If you are flat out on the straight and you are above a certain threshold - above 95% throttle for more than one second, and you are above 180km/h and you see a 120KW torque reduction - it flashes the rear light for a second to warn the driver behind."

from https://www.autosport.com/f1/news/11293 ... uel-saving

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PlatinumZealot
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Joined: 12 Jun 2008, 03:45

Re: When does an F1 car's rear light flash?

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Tommy Cookers wrote:
16 Nov 2017, 14:39
maybe this is now clear to everyone except me
what does the red flashing light before braking mean ?

(a) 120 kW or some other kW of K motor action is absent
(b) 120 kW or some other kW of K generator action is present
(c) both of the above
Generator is charging from the rear wheels. Like "caution air brakes" on a truck.
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