## Start Procedure

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
strad wrote:put you right foot on the floor and pop the clutch...And they don't haze let alone smoke the tires?

It's not a 100% drop. Like today's F1 starts. At the start, you drop the clutch to a specified point, which is calculated off the bite point find.

raymondu999

Joined: 4 Feb 2010

This topic pops up every few months. Take your pick of recent threads rehashing the same issues....

viewtopic.php?f=6&t=11564
viewtopic.php?f=1&t=10604
viewtopic.php?f=4&t=10851
viewtopic.php?f=4&t=9835
viewtopic.php?f=4&t=8910

The driver has to control the revs with a right foot on a pedal which has a linear mapping to the throttle ranging from 0% to 100%.

They have two clutch paddles on the steering wheel. They hold one at what they think is the bite point, while the second is pulled in to completely disengage the clutch. When the lights go out, the second paddle is dumped so the clutch control reverts to the first partially engaged paddle. That partial paddle is more gently released.

There are secondary factors that can be set to ensure the best probability of a smooth launch including an electronic routine to empirically find the optimum clutch pressure on the out lap. The teams use the car telemetry to find the relevant data relating to wheel spin and clutch biting point. That empirical routine calibrates the settings to match the actual conditions of the tyre, clutch plates and track surface. They then instruct the driver twiddle the appropriate settings to get the optimum launch conditions.

However the success of a start is down to the sensitivity of the driver's fingers and foot. The balance of rev control and clutch control results in some drivers making a perfect start, some having too much wheel spin, and others getting bogged down.

Here are two videos that mention the clutch slip setting on the wheel.

richard_leeds

Joined: 15 Apr 2009
Location: UK

rjsa wrote:
hardingfv32 wrote:Based on the stated rules, the driver must control the throttle with the pedal. I can see where the clutch can be set to optimize the launch a 13,000 rpm, so the driver is responsible for pegging the 13k mark. Could the throttle map have a flat or broad step in it at 13k rpm range? Extra pedal travel in this area of the map. How might this effect the normal use of the throttle map during the race? I assume a throttle position of 13k at idle is not the same as 13k under load.

Brian

Throttle maps are pretty restricted:

5.5.4 The accelerator pedal shaping map in the ECU may only be linked to the type of the tyres fitted to the car : one map for use with dry‐weather tyres and one map for use with intermediate or wet‐weather tyres.
5.5.5 At any given engine speed the driver torque demand map must be monotonically increasing
for an increase in accelerator pedal position.

In recent past teams would have one qualy map which would favour the performance of the EBD and then replace it for the race with another one that would burn less fuel and be gentler on the engine. That was forbidden, now they can't replace map after qualy. Then the car will start with one wet and one dry map. And item 5.5.5 pretty much avoids the existence of such plateau.

What about a "security" avoiding engine to run faster than 13000rpm if it runs at idle? We all know that drivers can reduce max rpm via map settings and in this case, they can press throttle pedal as far as they want, engine will never run faster than allowed by its map.
It shouldn't be difficult to have a special map like this for the start. This "start" map would be replace by a normal map as soon as driver fully releases clutch paddles.
Lurk

Joined: 13 Feb 2010

Lurk wrote:What about a "security" avoiding engine to run faster than 13000rpm if it runs at idle? We all know that drivers can reduce max rpm via map settings and in this case, they can press throttle pedal as far as they want, engine will never run faster than allowed by its map.
It shouldn't be difficult to have a special map like this for the start. This "start" map would be replace by a normal map as soon as driver fully releases clutch paddles.

There are only two maps. One dry track map and one wet track map. Exactly to avoid this kind of stunt.
rjsa

Joined: 2 Mar 2007

Teams previously had start maps that were nearly as effective as launch control. The FIA initially tried to restrict those with the requirement that start maps had to be used for the entire first lap, but in practice that just meant everyone drove around on the first lap with "launch control" engaged.

Teams had qualifying maps, start maps, race maps, safety car maps, etc. McLaren's overall engine mapping got so sophisticated that their drivers changed map settings with every gear shift via steering wheel paddles actuated by the normal gearbox paddles.

The end result of all that jostling is that now, as rjsa has said, cars only have dry/wet maps and they have to maintain first gear at the start until the car reaches 100kph. (Yet, Ferrari is still somehow getting much better starts than the rest of the field.)
bhallg2k

Joined: 28 Feb 2006

richard_leeds wrote:The driver has to control the revs with a right foot on a pedal which has a linear mapping to the throttle ranging from 0% to 100%.

It does not have to be linear, just 'monotonically increasing'.

Brian
hardingfv32

Joined: 3 Apr 2011

Lurk wrote:What about a "security" avoiding engine to run faster than 13000rpm if it runs at idle? We all know that drivers can reduce max rpm via map settings and in this case, they can press throttle pedal as far as they want, engine will never run faster than allowed by its map.

How would the engine know it is at idle, it has no wheel speed information available.

Brian
hardingfv32

Joined: 3 Apr 2011

rjsa wrote:There are only two maps.

Three to be precise: dry, inter, and wet.

Brian
hardingfv32

Joined: 3 Apr 2011

It's only two.

5.5.4 The accelerator pedal shaping map in the ECU may only be linked to the type of the tyres fitted to the car : one map for use with dry-weather tyres and one map for use with intermediate or wet-weather tyres.
bhallg2k

Joined: 28 Feb 2006

Ive been watching starts for a while and yes there is a special start map, but remember this is locked in for the first 90 seconds of the race, but for 2013 could be locked in for the first 2 laps in order to make the cars harder to drive early on.

One thing has made me think recently, Renault use 8,000rpm for a start and Mercedes use 13,000rpm for a start, Ferrari are at arround 14,000rpm for a start. The Renault powered cars have been lightning all season off the grid, why?
ESPImperium

Joined: 5 Apr 2008
Location: Glasgow, Scotland

I thought they did away with start maps by requiring that the same maps had to be used for both qualifying and the race. Am I confused on that one?

Oh, and the F2012's engine sits at 13,200 RPM for the start. You can see it on Massa's wheel from the Malaysia on-board video.
bhallg2k

Joined: 28 Feb 2006

" 5.6.3 The maximum throttle target map in the ECU may only be used to avoid throttle target
oscillations when the change of torque is small for a change of throttle position. It must not be
used to artificially reduce the maximum engine torque.
The selection of the maximum throttle target map will be fixed during qualifying and race. in the ECU may only be used to avoid throttle target
oscillations when the change of torque is small for a change of throttle position. It must not be
used to artificially reduce the maximum engine torque.
The selection of the maximum throttle target map will be fixed during qualifying and race."

What is a "maximum throttle target map" used for?

Brian
hardingfv32

Joined: 3 Apr 2011

bhallg2k wrote:It's only two.

5.5.4 The accelerator pedal shaping map in the ECU may only be linked to the type of the tyres fitted to the car : one map for use with dry-weather tyres and one map for use with intermediate or wet-weather tyres.

This is not 2 engine maps but to accelerator pedal shaping maps.
They have more than 2 engine maps. The only thing which changed in 2011 was teams cannot load anymore a new set of map between qualifying and race to avoid extreme EBD maps.

McLaren have at least 5 maps if I remember correctly, as the 4th is extreme fuel saving mode and they also have an overtake button. If someone has ECU specs, we sould be able to find maximum number of engine spec.

Lurk wrote:What about a "security" avoiding engine to run faster than 13000rpm if it runs at idle?

I was thinking about the clutch position but 5.6.4 forbids it
5.6.4 Engine control must not be influenced by clutch position, movement or operation.

In the other hand...
5.6.7 A number of engine protections are available in the ECU.
A minimum of nine seconds hold time should be configured for the engine protections enabled during qualifying and race. The configuration of the air tray fire detection and throttle failsafe are exceptionally unrestricted in order to allow each team to achieve the best level of safety.

Could they use that? They engage an engine protection more than 9s before the start then remove the restriction during the start. I found nothing about when engine protection can be activated/deactivated or what they are exactly...

BTW, some rules which could interest us.
5.6 Engine control :
5.6.1 The maximum delay allowed, computed from the respective signals as recorded by the ADR or ECU, between the accelerator pedal position input signal and the corresponding output demand being achieved is 50ms.
5.6.2 Teams may be required to demonstrate the accuracy of the engine configurations used by the ECU.
5.6.3 The maximum throttle target map in the ECU may only be used to avoid throttle target oscillations when the change of torque is small for a change of throttle position. It must not be used to artificially reduce the maximum engine torque.
The selection of the maximum throttle target map will be fixed during qualifying and race.
5.6.4 Engine control must not be influenced by clutch position, movement or operation.
5.6.5 The idle speed control target may not exceed 5,000rpm.
5.6.6 Except when anti-stall or idle speed control are active, ignition base offsets may only be applied above 80% throttle and 15,000rpm and for the sole purpose of reducing cylinder pressure for reliability.
5.6.7 A number of engine protections are available in the ECU.
A minimum of nine seconds hold time should be configured for the engine protections enabled during qualifying and race. The configuration of the air tray fire detection and throttle failsafe are exceptionally unrestricted in order to allow each team to achieve the best level of safety.

5.7 Engine high rev limits :
Engine high rev limits may vary for differing conditions provided all are significantly above the peak of the engine torque curve. However, a lower rev limit may be used when :
- The gearbox is in neutral.
- Stall prevention is active.
- The driver clutch request is greater than 95% of the total available travel of the driver clutch actuation device, used only to protect the engine following a driver error.
- An engine protection is active.
- The bite point finder strategy is active.
- The safety car is deployed or during the formation lap.
Except for the above conditions, ignition, fuelling and throttle may not be used to artificially control the engine speed or alter the engine response in a rev range more than 1,000rpm below the final rev limit.
Lurk

Joined: 13 Feb 2010

F2012 steeringwheel:

There is a start toggle at the bottom.

Mercedes AMG F1 W03 wheel:

HRT F112 Wheel:

Marussia MR01 wheel:

ESPImperium

Joined: 5 Apr 2008
Location: Glasgow, Scotland

Lurk wrote:5.6.7 A number of engine protections are available in the ECU.
A minimum of nine seconds hold time should be configured for the engine protections enabled during qualifying and race. The configuration of the air tray fire detection and throttle failsafe are exceptionally unrestricted in order to allow each team to achieve the best level of safety.

Could they use that? They engage an engine protection more than 9s before the start then remove the restriction during the start. I found nothing about when engine protection can be activated/deactivated or what they are exactly...

You would think that one of the safety system's sensor would have to be activated to do what you are suggesting. Falsely closing the sensor circuit would seem like a violation. Most sensors are FIA approved.

Brian
hardingfv32

Joined: 3 Apr 2011

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