EBD Ban Work Arounds

[eyalynf1]

Jumping right in...

I've got an idea for the impending EBD ban. The ban actually has to do with non-driver controlled throttles. So why not just remove the throttle, similar to the way the BMW's Valvtronic system works. Timing and duration of valve stroke would then modulate engine power.

Or, utilize a small plenum pressurized with hot exhaust gases. On throttle, the plenum is pressurized and releases exhaust gases to the diffuser in the normal fashion. Off throttle, the pressurized gas releases to the diffuser at a minimally decreasing rate as the pressure decreases.

Any other bright ideas/comments?

[tommylommykins]

is it possible to look at this in terms of 'energy'?

Fuel is the thing that provides energy to an F1 car. Energy is used to suck the car down onto the track. By limiting the amount of fuel, and therefore energy, that can go into the engine, you have no energy left to suck the car onto the track.


I don't understand your first proposition.

In the case of your second system, you are suggesting a 'gas powered battery'. I imagine it would be very hard to store up enough energy in such a gas-battery to actually make a difference, I imagine it's easy maths to do to work out the pressures/volumes you'd need to make it work, but, off the top of my head, I imagine it's a lot

[hardingfv32]

First, what is your definition of the word throttle? They will be targeting the driver's control of engine output. Maybe add something like fuel use must be proportional to engine crankshaft output. The teams are not going to expend resources in this area if they know FIA is against it. If you come up with something it would be banned in short order.

Brian

[ringo]

One work around is left foot braking, or in better terms, the driver riding the throttle while braking to keep the diffuser blowing.
Fancy clutch settings can be used to to assist this.

10% restriction only means something if the driver is off throttle and the engine is throttling and retarding itself.

If the driver is on throttle and the engine is retarding in the mean time, then it can't be looked at as forcible manipulation of the aero.
It cannot be distinguished from typical influence the exhaust has on the car in a literal sense.

So if the the driver goes on throttle with a certain throttle setting instead of an automated engine map, it should be perfectly legal.

[hardingfv32]

Is that practical at this time? I thought that the brakes were somewhat restricted due to thickness restrictions. You might be able to use the technique for a few laps during qualifing but not a whole race. Then there is the issue of balance if the technique is not being used.

Brian

[eyalynf1]

Ideally the driver would control both clutch and throttle to maintain exhaust flow through cornering. From a driver involvement standpoint that would be best. But given the constraintson clutch design and the interactions with regenerative braking I don't see this working.

By throttle I mean the butterfly valve used to restrict airflow from the airbox to the cylinder intake valves. The only question is whether the use of valve timing and fuel regulation alone can provide adequate torque output control. The ecu probably already does this in some fashion and could probably be used to provide EBD flow control.

Really the output of the exhaust and the downforce it produces is a function of the increased mass flow of air that it provides. The plenum would provide buffered mass flow, just like streaming video, and keep the flow relatively constant.

[hardingfv32]

I'm not sure that the engine just pumping air is going to cut it. Look at how small the plenum opening is near the roll bars. Sure, every bit helps, but I think it is the conversion of fuel into heat that makes the blown diffusers really affective.

Brian

[twoshots]

I'm not sure that the engine just pumping air is going to cut it. Look at how small the plenum opening is near the roll bars. Sure, every bit helps, but I think it is the conversion of fuel into heat that makes the blown diffusers really affective.

Brian

Remember that the air/fuel mixture that is being 'blown' through the engine still passes through red hot exhausts, igniting the fuel anyway.

[ESPImperium]

Pretty sure that VVT/VVTi and all systems like that are all banned under the technichal regs.

The area the Exaust Blown Diffuser and Engine Overrun Mapping gets arround the rules is it is all down to the way they control the throttle, and how the teams electronics keep on full throttle and dis-engage the clutch so the driver can brake.

The EBD/EOM is a clever thing, just there are ways that the engine guys go about it can be misjudged, and this is what WIlliams/Virgin came up with as the way they were looking at was beyond the grey areas that the other teams are all using.

[horse]

One work around is left foot braking, or in better terms, the driver riding the throttle while braking to keep the diffuser blowing.

If the driver is on throttle and the engine is retarding in the mean time, then it can't be looked at as forcible manipulation of the aero.

I think using the brake to engage a retarded engine map must also be considered as driver influenced if coming off the throttle is considered so. Decelerating, Braking, changing gears - I don't see any way you could engage an engine map on these actions and not face penalty. Surely just leaving the throttle open with a clutch in is not going happen - there will be a lot more toasted engines.

Anyway, the bodywork of the car is a sort of plenum. Renault are using their bodywork to enhance the flow over the diffuser. Perhaps this gives some storage potential, but without the retarded engine map, as mentioned previously, your input energy will simply be not as pronounced.

[PhillipM]

^^I'd be very surprised if the teams didn't already have engine maps for every different gear and had them for a long, long time tbh!

[void]

Can some teams change the engine map control to padles?

[Muulka]

One work around is left foot braking, or in better terms, the driver riding the throttle while braking to keep the diffuser blowing.
Fancy clutch settings can be used to to assist this.

10% restriction only means something if the driver is off throttle and the engine is throttling and retarding itself.

If the driver is on throttle and the engine is retarding in the mean time, then it can't be looked at as forcible manipulation of the aero.
It cannot be distinguished from typical influence the exhaust has on the car in a literal sense.

So if the the driver goes on throttle with a certain throttle setting instead of an automated engine map, it should be perfectly legal.

I'm pretty sure that the engine shuts itself down if both throttle and brake are on at the same time as a safety measure against stuck throttles.

Feel free to correct me.

[hardingfv32]

A) "The area the Exhaust Blown Diffuser and Engine Overrun Mapping gets around the rules is it is all down to the way they control the throttle, and how the teams electronics keep on full throttle and dis-engage the clutch so the driver can brake."

This is not the case.

1) The clutch can only manipulate the engine for shifts. The driver must control the clutch at all other times.
2) You have KERS to recharge off the front on the engine, so the engine can not be disengaged during most braking.

B) "I'd be very surprised if the teams didn't already have engine maps for every different gear and had them for a long, long time tbh!"

Maps must be controlled by the driver only. There is no integration with the gear selection system.

C) "Can some teams change the engine map control to padles?"

There is no value in this. One map can handle both on and off throttle conditions. The off throttle fuel burning has or relevance to the normal on throttle map.

D) "I'm pretty sure that the engine shuts itself down if both throttle and brake are on at the same time as a safety measure against stuck throttles."

I would say all cars have fly by wire throttle control. There are no stuck throttles. Normally closed is the fail safe condition for the loss of power.

Brian

[eyalynf1]

One work around is left foot braking, or in better terms, the driver riding the throttle while braking to keep the diffuser blowing.

If the driver is on throttle and the engine is retarding in the mean time, then it can't be looked at as forcible manipulation of the aero.

I think using the brake to engage a retarded engine map must also be considered as driver influenced if coming off the throttle is considered so. Decelerating, Braking, changing gears - I don't see any way you could engage an engine map on these actions and not face penalty. Surely just leaving the throttle open with a clutch in is not going happen - there will be a lot more toasted engines.

Anyway, the bodywork of the car is a sort of plenum. Renault are using their bodywork to enhance the flow over the diffuser. Perhaps this gives some storage potential, but without the retarded engine map, as mentioned previously, your input energy will simply be not as pronounced.

Engine fuel/air ratio is currently driver adjustable via the steering wheel. Why not ignition/injection timing as well? The increased mass flow associated with retarded ignition would be preserved. With regard to VVT, this is illegal...but it still may be possible to modulate engine torque with ignition/injection timing keyed to throttle position rather than using a throttle or valve timing.

As far as the input "energy" is concerned, If Bernoulli's equation is used to model the input to the diffuser, the advantage of EBD is in the increased volume of gas flow through the diffuser due to exhasut being added to ambient air. As with any reciprocating, fixed displacement pump, the rate of gas flow is dependent on speed. If engine speed could be kept high via regenerative braking/downshifting, the the gas flow should be the same under part torque conditions.