Blown Diffuser??

[747heavy]

Hi Marcus,

Does Red Bull has brake problems sometimes?
just being a smartarse - sorry

It would be/is, but if they use their trick engine map to reduce
the power output under this conditions significantly, you would only
have the loss in engine braking.

If the downforce advantage of the EBD is large enough, it is may worth it.
But in any case, you will need to brake more/harder, if you want the same entry speed.
Saying this, with more downforce from the EBD, you can maybe carry more speed into the corner, so the downside of the loss in engine braking is maybe not that big. - I don´t know, just some thoughts

Have a nice weekend

[autogyro]

What you need is a gearbox that can simulate engine braking and also allow the engine to be disconnected from the powertrain to work independently.
Hmm, where did I see such a unit?

[flynfrog]

What you need is a gearbox that can simulate engine braking and also allow the engine to be disconnected from the powertrain to work independently.
Hmm, where did I see such a unit?

a train

[WhiteBlue]

Who says, that the driver in this EBD application, not just maintains a degree of throttle with his foot. I don´t think, that the rules specify, that you have to lift completely off the throttle why you are braking.

Of course you are right 747heavy. All that is demanded in the regs is a zero throttle pedal to correlate with zero throttle and 100% pedal with 100% throttle. Even an extreme like zero throttle from 0-1% and 100% throttle from 1-100% would be legal. Anything between would be also legal. There is no requirement that the function between 0-100% pedal is linear, continuous or continuous differentiable. It can be a simple jump, a non linear function or anything that suits the purpose.

[Pierce89]

NO---don't agree there my gyratory forum brother..

retarding ignition will CAUSE detonation of the mixture.

the ignition needs to be advanced to keep up with the piston speeds. Not advancing it far enough means that the cylinder copression will pre-ignite the fuel. Retarding ignition will cuase issues. You cannot wait long enough to allow the exhaust valves to open and then fire the sparkplug. By that time the high compresion will have detonated the fuel charge.

Is it only me that sees this? Can someone not put me right if I am wrong?

My experience is through ym racing bikes and creating my own maps for ignition and tailoring this to suit compression and fuel octane (knock resistance) so I do feel I know about this...

The exhaust valve is open. no compression

[speedsense]

Who says, that the driver in this EBD application, not just maintains a degree of throttle with his foot. I don´t think, that the rules specify, that you have to lift completely off the throttle why you are braking.

Of course you are right 747heavy. All that is demanded in the regs is a zero throttle pedal to correlate with zero throttle and 100% pedal with 100% throttle. Even an extreme like zero throttle from 0-1% and 100% throttle from 1-100% would be legal. Anything between would be also legal. There is no requirement that the function between 0-100% pedal is linear, continuous or continuous differentiable. It can be a simple jump, a non linear function or anything that suits the purpose.

Sure, you could do it that way, but you would be fooling the ECU in doing so. Give the ECU garbage numbers and you will have a car that runs like garbage, or not at all..not that it couldn't be done that way, though many of the parameters in the ECU would have to be changed for this "new" throttle position.
Calibrating the throttle sensor to something other that what the ECU expects, will to lead to unexpected results.
The stationary rules are an important consideration, 3 seconds is ample time to upload new maps. Re calibrating the throttle (qualifying or race differences) takes more time than.

[marcush.]

Hi Marcus,

Does Red Bull has brake problems sometimes?
just being a smartarse - sorry

It would be/is, but if they use their trick engine map to reduce
the power output under this conditions significantly, you would only
have the loss in engine braking.

If the downforce advantage of the EBD is large enough, it is may worth it.
But in any case, you will need to brake more/harder, if you want the same entry speed.
Saying this, with more downforce from the EBD, you can maybe carry more speed into the corner, so the downside of the loss in engine braking is maybe not that big. - I don´t know, just some thoughts

Have a nice weekend

in modern cars with throttle actuators the throttle closing time in an going off throttle situation is quite often slowish which is about what wwe are talking here.The experience for the driver is not nice as the car seems to push on isntead of slowing as you go of throttle...at least for an instant..disturbing that is .. It might not be so pronounced with the driver left foot braking though..
But putting this much heat into the system by reatarding the ignition can´t be good for reliability...
So ...we saw Vettel having this retard functionality activated during the race also in power on situations when his Engine sounded crap and showed power loss.
leading to plug failure...???

[autogyro]

F1 Regulations

5.5 Engine throttles :
5.5.1 The only means by which the driver may control the engine throttle positions is via a single chassis
mounted foot pedal.
5.5.2 Designs which allow specific points along the pedal travel range to be identified by the driver or assist him
to hold a position are not permitted.
5.5.3 The minimum and maximum throttle pedal travel positions must correspond to the engine throttle minimum
(nominal idle) and maximum open positions

5.9 Engine actuators :
With the following exceptions hydraulic, pneumatic or electronic actuation is forbidden :
a) Electronic solenoids uniquely for the control of engine fluids ;
b) Components providing controlled pressure air for a pneumatic valve system ;
c) A single actuator to operate the throttle system of the engine ;
d) Any components required as part of a KERS.


ARTICLE 8 : ELECTRICAL SYSTEMS
8.1 Software and electronics inspection :
8.1.1 Prior to the start of each season the complete electrical system on the car must be examined and all on
board and communications software must be inspected by the FIA Technical Department.
The FIA must be notified of any changes prior to the Event at which such changes are intended to be
implemented.
8.1.2 All re-programmable microprocessors must have a mechanism that allows the FIA to accurately identify
the software version loaded.
8.1.3 All electronic units containing a programmable device, and which are intended for use at an Event, must be
presented to the FIA before each Event in order that they can be identified.
8.1.4 All on-car software versions must be registered with the FIA before use.
8.1.5 The FIA must be able to test the operation of any compulsory electronic safety systems at any time during
an Event.
8.2 Control electronics :
8.2.1 All components of the engine, gearbox, clutch, differential and KERS in addition to all associated actuators
must be controlled by an Electronic Control Unit (ECU) which has been manufactured by an FIA
designated supplier to a specification determined by the FIA.
The ECU may only be used with FIA approved software and may only be connected to the control system
wiring loom, sensors and actuators in an manner specified by the FIA.
8.2.2 All control sensors, actuators and FIA monitoring sensors will be specified and homologated by the FIA.
Each and every component of the control system will be sealed and uniquely identified and their identities
tracked through their life cycle.
These components and units may not be disassembled or modified in any way and seals and identifiers
must remain intact and legible.
8.2.3 The control system wiring loom connectivity will be specified by the FIA.
8.2.4 Pneumatic valve pressure may only be controlled via a passive mechanical regulator or from the ECU and
its operation will be monitored by the ECU.
8.2.5 The car hydraulic system will be monitored by the ECU.
8.2.6 The ECU will be designed to run from a car system supply voltage of 12V nominal provided by a
homologated voltage regulator.
8.3 Start systems :
Any system, the purpose and/or effect of which is to detect when a race start signal is given, is not
permitted.
8.4 Data acquisition :
Any data acquisition system, telemetry system or associated sensors additional to those provided by the
ECU and ADR must be physically separate and completely isolated from any control electronics with the
exception of the primary regulated voltage supply, car system ground and a single communication link to
the ECU and ADR.
8.5 Telemetry :
8.5.1 Telemetry systems must operate at frequencies which have been approved by the FIA.

[autogyro]

With a decent KERS system, it is possible to disengage the engine from the drivetrain and use the over run braking to charge the KERS storage while at the same time using this operation to simulate engine braking.
Control is allowed for this.
During this braking faze it would then be possible to control the throttle either manualy (or by other means under the KERS regulations), to maintain EBD gas flow.
Not only would complete control over the diffuser result but also energy would be recovered at the same time.
Of course the current obsolete KERS systems would not adapt to this operational method. Something new is needed.

[autogyro]

Following on from this.
If future regulations restrict DF to 50 percent or less and also couple this to restrictions on fuel used, then it becomes possible to use the here projected KERS coupled much more efficient Exhaust Blown Diffuser as a switch on, switch off low drag DF generator, within the reduced DF maximum, giving downforce when needed when cornering and not on the straits where drag would there bye be considerably reduced. I rough estimate some 20 percent improvement in energy use with the 1.5 turbo engine formula but with the same lap times as current.
Achieving this would ensure a future for F1.

[WhiteBlue]

Who says, that the driver in this EBD application, not just maintains a degree of throttle with his foot. I don´t think, that the rules specify, that you have to lift completely off the throttle why you are braking.

Of course you are right 747heavy. All that is demanded in the regs is a zero throttle pedal to correlate with zero throttle and 100% pedal with 100% throttle. Even an extreme like zero throttle from 0-1% and 100% throttle from 1-100% would be legal. Anything between would be also legal. There is no requirement that the function between 0-100% pedal is linear, continuous or continuous differentiable. It can be a simple jump, a non linear function or anything that suits the purpose.

Sure, you could do it that way, but you would be fooling the ECU in doing so. Give the ECU garbage numbers and you will have a car that runs like garbage, or not at all..not that it couldn't be done that way, though many of the parameters in the ECU would have to be changed for this "new" throttle position.
Calibrating the throttle sensor to something other that what the ECU expects, will to lead to unexpected results. The stationary rules are an important consideration, 3 seconds is ample time to upload new maps. Re calibrating the throttle (qualifying or race differences) takes more time than.

Speedsense, I do not understand your logic there. It has been shown that F1 today uses at least seven pre programmed different throttle maps. You are aware that the drivers use dual gear shifters at the steering wheel that change the engine maps with every gear change, do you?

It is not a big jump to assume that the drivers can have an additional "boost button" on the steering wheel that inserts special maps in the three middle gears from third to fifth for qualifying. Actually these special maps would not be needed at full speed or in acceleration in the lowest gears.

I fail to understand how this would fool the ECU or would need the car to be stationary.

I see more merit in the point that knocking could be a serious problem. F1 engines have no variable valve timing which would help this application tremendously. This is why is has been suggested to use variable fuel injection to suppress the engine knocking. It is also known that the McLaren SECU unit has an ion current sensor option. If teams are using this sensors they would have much better knowledge from working stroke to working stroke how the ignition actually behaved and they could use modulated fuel injection more efficiently. So it becomes a question if those units are actually legal now or not.

[747heavy]

@ speedsense,

Hi speedsense,

Look I do not know, what they are doing or what they are not doing - it´s just a guess.

As for the "fooling the ECU" thought. I don`t know, what you drive as a road car, and what
other road car manufacturers doing at the moment. But, a couple of years ago, I nearly run
my car (Audi with DBW) off the road in the winter, while trying to left foot brake in a corner.

Why??
Because as soon as I touched the brake, the ECU would "override" my throttle request, and stoped injecting fuel. At the time I was not expecting it, I thought the ECU would just follow my request, for some power from the engine, as I was applying throttle.
But it did not - it "decided" that I wanted to brake and "ignored" my throttle/power request.

BTW:
In most modern road cars this is done to safe fuel under braking, as left foot braking is not considered a "normal" way to drive a road car.

What I want to say?
That one condition (in this case braking) can be used to "tell" the ECU that we are not in a normal x% throttle application, and the ECU would not try to apply a standard x% throttle map. Therefore it would have no influence on normal engine operation.

@autogyro

As for your KERS thought, why I can follow your line of thought, it would come at a huge
weight/cost penality - I don´t think RBR is using a KERS system just to gain that advantage.
What they do with there engine map is similar to what is done in many turbo cars to keep the
turbo spooling(maintain boost) while braking.
It´s smart but it´s not rocket science.
The trick is to keep the termal load on your engine/exhaust system in check, while still gaining the advantage.

Cheers

[Richard]

Speedsense - The maps are programmed in the SECU in the garage. A change of ignition map can only be selected when stationary. A change of throttle map can be changed at any time.

So there could be a Q3 retarded ignition map that provides hot exhaust gas at low revs. It is selected during the Q3 pits stop. It can't run for the whole race because it would destroy the engine/exhaust.

As for throttle maps - Yes, the rules say that 0% throttle must equal nominal idle. However, WB's idea is for 1% throttle to give high exhaust flow but low power, ie a very fast idle with lean mix. As long as the driver doesn't take his foot off the pedal, then gasses keep flowing.

[autogyro]

@ speedsense,

Hi speedsense,

Look I do not know, what they are doing or what they are not doing - it´s just a guess.

As for the "fooling the ECU" thought. I don`t know, what you drive as a road car, and what
other road car manufacturers doing at the moment. But, a couple of years ago, I nearly run
my car (Audi with DBW) off the road in the winter, while trying to left foot brake in a corner.

Why??
Because as soon as I touched the brake, the ECU would "override" my throttle request, and stoped injecting fuel. At the time I was not expecting it, I thought the ECU would just follow my request, for some power from the engine, as I was applying throttle.
But it did not - it "decided" that I wanted to brake and "ignored" my throttle/power request.

BTW:
In most modern road cars this is done to safe fuel under braking, as left foot braking is not considered a "normal" way to drive a road car.

What I want to say?
That one condition (in this case braking) can be used to "tell" the ECU that we are not in a normal x% throttle application, and the ECU would not try to apply a standard x% throttle map. Therefore it would have no influence on normal engine operation.

@autogyro

As for your KERS thought, why I can follow your line of thought, it would come at a huge
weight/cost penality - I don´t think RBR is using a KERS system just to gain that advantage.
What they do with there engine map is similar to what is done in many turbo cars to keep the
turbo spooling(maintain boost) while braking.
It´s smart but it´s not rocket science.
The trick is to keep the termal load on your engine/exhaust system in check, while still gaining the advantage.

Cheers

I accept the cost penalty (outside investment in KERS allowed in regs) but the KERS I have in mind would be lighter than any current Kers system and would be intigral with the powertrain with no extra motor/generators or gearing systems, just the energy storage and the control electronics.
You will never get complete control over an EBD until you can disconnect the engine from the rest of the powertrain.

[747heavy]

Hi autogyro,

Yeap see your point.
In theory the best solution for a EBD car would be to run an CVT gearbox, so you can
keep the engine at it´s optimum operation point.
Not sure if the sound of such a car would be very appealing for the general public.

As an crude way to do this now, you could simply clutch, and let the engine at max rpm (the rev limiter takes car of the rest), to maintain full exhaust flow.
Just kidding......