2014 F1 Engines - throttleless?

[wuzak]

Is it possible that the new F1 engines could do without throttles (butterfly or otherwise)?

In road car SI engines without throttles, variable valve control and lift has been used to provide the engine speed control, in conjunction with spark and fuel (direct) injection timing.

The new F1 engines do not have variable valve timing and lift. They do, however, have direct injection and have had, for a long time, control over spark timing.

The new F1 engines also have the MGU-H. With this they can control the boost pressure and flow rate of the air to the engine, either speeding it up or slowing it down as required.

There will be a period where the turbo will not need the MGU-H to control its speed, and the MGU-H can be disconnected. I would think this would be equivalent to a wide open throttle situation, so would be no different to the case of an engine with throttles.

Could it work?

[Holm86]

Is it possible that the new F1 engines could do without throttles (butterfly or otherwise)?

In road car SI engines without throttles, variable valve control and lift has been used to provide the engine speed control, in conjunction with spark and fuel (direct) injection timing.

The new F1 engines do not have variable valve timing and lift. They do, however, have direct injection and have had, for a long time, control over spark timing.

The new F1 engines also have the MGU-H. With this they can control the boost pressure and flow rate of the air to the engine, either speeding it up or slowing it down as required.

There will be a period where the turbo will not need the MGU-H to control its speed, and the MGU-H can be disconnected. I would think this would be equivalent to a wide open throttle situation, so would be no different to the case of an engine with throttles.

Could it work?

Think it would be very hard to control the airflow precisely enough just with the MGU-H. But I've been talking a lot in different threads about having the throttles wide open at 0% throttle (except at idle). That would give a lot of the pros of a throttleless system.

[wuzak]

Not having thrittles should improve efficiency across the whole operating range. Even when fully open throttles affect the airflow.

[Holm86]

Not having thrittles should improve efficiency across the whole operating range. Even when fully open throttles affect the airflow.

Don't think that's such a big problem in a turbocharged engine. More in a naturally aspirated engine where the volumetric efficiency is crucial for what sort of performance the engine can have.

I still think it would be to difficult controlling the airflow only via the turbo and MGU-H.

[Lycoming]

Not having thrittles should improve efficiency across the whole operating range. Even when fully open throttles affect the airflow.

Not by very much, especially if since they aren't mounting it across an air restrictor. I agree with Holm; the potential gain there is so small, its just not worth it.

[Manoah2u]

is it? regarding the 100k fuel rule, any form of fuel saving/efficiency is an extra. if you can gain just the tiniest bit over 60 laps, i'm sure the teams would welcome such a possibility. it probably will be paired with the question regarding how beneficial it is regarding engine/engine part wear [including the electric devices]. saving fuel is 1 thing, keeping things intact is far more important.

[Lycoming]

It is. Because if it were worth it, they could just use slide throttles, which offer 0 obstruction at WOT, but is easier to implement than the scheme discussed above and probably would allow for better driveability.

[wuzak]

It is. Because if it were worth it, they could just use slide throttles, which offer 0 obstruction at WOT, but is easier to implement than the scheme discussed above and probably would allow for better driveability.

If the slide throttle was all that was required, why do they still use butterflies?

There are downsides to the slide throttles, I believe, but I am unsure as to what they are.

[wuzak]

Not having thrittles should improve efficiency across the whole operating range. Even when fully open throttles affect the airflow.

Not by very much, especially if since they aren't mounting it across an air restrictor. I agree with Holm; the potential gain there is so small, its just not worth it.

What aren't we mounting across an air restrictor?

[PlatinumZealot]

So how does one control the air flow? only with extra fuel injection, resultant engine speed and MGU-H?

It can work but think about how fast the engine will respond what happens when the battery is done?...
Think about it!

[Tommy Cookers]

Is it possible that the new F1 engines could do without throttles (butterfly or otherwise)? .......
The new F1 engines also have the MGU-H. With this they can control the boost pressure and flow rate of the air to the engine, either speeding it up or slowing it down as required. .....

in principle they could run unthrottled over a worthwhile power range, entirely by control of supercharger rpm via the mgu-h
that power range would be from (slightly below) 1600 cc N/A WOT power to 1600 cc turbocharged/turbocompounded WOT power
but running at low boost, zero boost, or even negative boost would not be very efficient with the CR fixed for high boost

N/A or supercharged, F1 extreme valve timing and tuned-length induction systems cause relatively poor filling at partial rpm
and so then need relatively less throttling anyway

re-reading the 3 Renault-derived articles on throttling and mapping in the Technology section of this site
shows the need for some throttling, sufficient to implement the throttle-mapped enhancement of race-controlabity they describe
and reminds us of the benefits of (2013) 4 cylinder running, presumably to be 3 cylinder running in 2014 ?
this would reduce throttling

there is anyway very little incentive to minimise fuel consumption at partial powers (so no need for efficiency then)
there will be significant partial power running to produce (fake) recovery from mgu-k generation as fuel for this is free
this will also help to minimise throttling

[gruntguru]

It is. Because if it were worth it, they could just use slide throttles, which offer 0 obstruction at WOT, but is easier to implement than the scheme discussed above and probably would allow for better driveability.

If the slide throttle was all that was required, why do they still use butterflies?

There are downsides to the slide throttles, I believe, but I am unsure as to what they are.

Not sure if any of them use butterflies. Barrel throttles (also smooth at WOT) have been standard practice in F1 for some time now.

[thisisatest]

renault has said (at least with the V8s) that they used butterflies. cost them like 3-5 horsepower but gained driveability at part throttle. that's the most often stated compromise with barrel throttles.

[gruntguru]

Another means of increasing cylinder load is cylinder deactivation or skipping. Renault has mentioned the possibility of skipping injection events in corners.

[riff_raff]

SI engines require some form of control over how much air mass flow passes through the engine, and it needs to be fairly precise due to the air/fuel mixture limits SI engines have. The MGU connected to the turbo does not provide the level of precision and response required for intake throttling on an F1 engine. VVT would work, but these systems are not allowed.

Skipping injection would provide some modulation of engine output, but the irregular combustion events introduce other issues.