2014-2020 Formula One 1.6l V6 turbo engine formula

[Holm86]

Yep I know how a normal exhaust brake works using the valves but surely a similar effect can be achieved using the turbo?

How?

[bhall]

Back pressure. Apply a load to the turbine - with the MGUH - and the turbine will create more back pressure.

[djos]

Yep I know how a normal exhaust brake works using the valves but surely a similar effect can be achieved using the turbo?

How?

Stopping the exhaust gases from moving freely from the engine will I postulate create back pressure and a compression braking like effect - likely not as strong as using the valves but possibly enuf to be useful in an F1 engine.

Like I said, I'm no engineer so my idea could be total BS.

[WhiteBlue]

There's a difference between the MGUH and the turbine itself, and it's far from given that teams will use the MGUH to control boost; some of us still think a relatively simple wastegate is the obvious solution....

Why would you have an expensive and heavy MGU-H in the first place if you do not use it to control boost and generate electricity. Just to spool the turbo up? That would not fit to anything we know.

[Holm86]

Any generator can be a motor, just operate it in reverse buy supplying current.

No not every generator can be used as a motor. It demands a permanent magnet and DC.

But why do you think I don't know this?? That's the point of MGU Motor Generator Unit. It works both as a motor and a generator. I know this.

But that doesn't change the fact that running it as a motor uses energy. And why on any sort of level would you want to waste energy to brake the engine?? When you have a MGU-K that creates energy from braking the engine.

[WhiteBlue]

Yep I know how a normal exhaust brake works using the valves but surely a similar effect can be achieved using the turbo?

How?

Stopping the exhaust gases from moving freely from the engine will I postulate create back pressure and a compression braking like effect - likely not as strong as using the valves but possibly enuf to be useful in an F1 engine...

If we assume that the engine will have a throttle - which it surely will have due to banning variable valves - then the engine braking should simply work by cutting the injection. But that would also cause the turbo to spin down due to lack of exhaust energy. So it is difficult to imagine how this works without more information. It is not desirable to spin down the turbo if you have to spin it up again when you have to power out of the corner.

I agree with Holm that the MGU-K is much better suited to the purpose of braking.

[bhall]

Why would you have an expensive and heavy MGU-H in the first place if you do not use it to control boost and generate electricity. Just to spool the turbo up? That would not fit to anything we know.

You'll have to forgive me, WB; I generally don't follow the specialized press that closely. I just read the regulations, do my best to interpret them, and use my cabeza to draw conclusions.

[djos]

The only possible use I can see for compression braking would be on the super slow circuits like Monaco to boost drivability and stability under braking - I can't see it being useful anywhere else.

In fact as others suggest it may not be useful at all.

I was merely interested in whether the concept was viable as a standalone idea regardless of its usefulness.

[WhiteBlue]

Talk is cheap, but it does not answer my question. Why do you have an MGU-H if not for boost limitation and electric power generation?

[wuzak]

No. Because he said that the turbo would help brake the engine. Which he also said sounded a bit strange to have the turbo braking the engine. To me it does not make any sense.

Just watched the episode.

He is saying that they can slow the turbo using the MGUH (or ERSH, as he says), which generates energy that can be stored and also increases back pressure on the engine, which will help engine braking. Not sure how much that will work.

Also, just thinking aloud, it woudl seem that if the engine has more engine braking then there is less for the MGUK (or ERSK) to do.

[Holm86]

If we assume that the engine will have a throttle - which it surely will have due to banning variable valves - then the engine braking should simply work by cutting the injection. But that would also cause the turbo to spin down due to lack of exhaust energy. So it is difficult to imagine how this works without more information. It is not desirable to spin down the turbo if you have to spin it up again when you have to power out of the corner.

I agree with Holm that the MGU-K is much better suited to the purpose of braking.

IMO they will cut ignition and fuel when off throttle, but keep the throttle bodies open if this is allowed. And then use the MGU-K for braking the engine. This cold blowing will keep pumping air though the engine, helping the turbine to keep spinning. Then you can either use the MGU-H to harvest more energy from the turbine, or let the turbine spin freely so you don't have to use as much energy spinning it back up when back on the throttle.

There's so many variables in how to harvest and use the electric energy next year. Pretty exciting.

[Holm86]

No. Because he said that the turbo would help brake the engine. Which he also said sounded a bit strange to have the turbo braking the engine. To me it does not make any sense.

Just watched the episode.

He is saying that they can slow the turbo using the MGUH (or ERSH, as he says), which generates energy that can be stored and also increases back pressure on the engine, which will help engine braking. Not sure how much that will work.

Also, just thinking aloud, it woudl seem that if the engine has more engine braking then there is less for the MGUK (or ERSK) to do.

Watched it last night so couldn't remember precisely how he said it. Just thought it sounded a bit wired.

And when it comes to engine braking you are correct. IMO they would want the smallest amount of natural engine braking. Leaving the engine braking to the MGU-K.

[WhiteBlue]

Just watched the episode.
He is saying that they can slow the turbo using the MGUH (or ERSH, as he says), which generates energy that can be stored and also increases back pressure on the engine, which will help engine braking.

It still does not make much sense to me. If the back pressure is increased it would mean that fuel is still injected. Without fuel you do not get significant exhaust energy and heat to have the turbine spun up. So it means you use fuel and that would not be consistent with engine braking. It does not fit.

[pgfpro]

If we assume that the engine will have a throttle - which it surely will have due to banning variable valves - then the engine braking should simply work by cutting the injection. But that would also cause the turbo to spin down due to lack of exhaust energy. So it is difficult to imagine how this works without more information. It is not desirable to spin down the turbo if you have to spin it up again when you have to power out of the corner.

I agree with Holm that the MGU-K is much better suited to the purpose of braking.

IMO they will cut ignition and fuel when off throttle, but keep the throttle bodies open if this is allowed. And then use the MGU-K for braking the engine. This cold blowing will keep pumping air though the engine, helping the turbine to keep spinning. Then you can either use the MGU-H to harvest more energy from the turbine, or let the turbine spin freely so you don't have to use as much energy spinning it back up when back on the throttle.

There's so many variables in how to harvest and use the electric energy next year. Pretty exciting.

I am pondering this and it might be the answer. If the engines is running at 10500 rpm and at 21psi boost pressure
(52lbs/min of air flow) and then you were to kill the injectors and ignition the engine at this same rpm would now be flowing around 0 boost and (21lbs/min of air flow with the throttle WO) You would still have to add fuel to keep energy at the turbine and keep its rpm from dropping off due to MGUH load. So at this point you would have to go into ignition retard to power out of the engine and not lose a ton of turbine rpm?

[wuzak]

If the back pressure is increased it would mean that fuel is still injected.

No, it does not.

Increased could be increased above normal at that point. In the overall scheme of things it could still be quite small.

Without fuel you do not get significant exhaust energy and heat to have the turbine spun up.

Firstly, the turbine has inertia. It's tendency is to want to keep spinning.

Whilst it is spinning it is making boost, which slows the turbo down. A closed throtlle will build up pressure and slow the turbine down faster.

But they can use the MGUH to slow the turbo down faster still and generate power doing it.

Meanwhile, the engine is still pumping air, even if no fuel is injected. If the turbine is slowed down more than normal and/or more quickly than normal, the resistance to the engine's pumping is greater (ie back pressure), and that will have the effect of slowing the engine down (ie engine braking).

Or look at it this way. The engine without fuel injected is just an air pump - a positive displacement compressor. Restrict the output in some way and the power required to drive it is greaater.