2014-2020 Formula One 1.6l V6 turbo engine formula

[mrluke]

an earlier post mentions 3.5 bar boost ie 3.5 bar absolute (if that can be believed)
many have calculated that as a turbo engine around only 2 bar abs is needed (the 1988 engines were 'only' 2.5 bar abs)
though I have evidenced the efficiency benefits of backpressure, 3.5 bar does not suggest backpressure any time soon

3.5 bar boost typically refers to 3.5 bar above atmospheric. i.e. 4.5 bar abs.

This becomes obvious when you talk about an engine running 0.5 bar boost, it is not being feed with lower than atmos pressure air.

As far as I understand it the mgu-h generates power by braking the turbo and thus controlling boost. This is going to cause higher back pressure pre turbo than in a traditional setup where the excess boost is bled out of the system via a wastegate. Clearly there must be a limit on how much load the turbine can deal with before a wastegate will need to open.

Feel free to correct If i have misunderstood.

[ppj13]

@ ppj (mostly)

AFAIK ....... a turbo is normally operating in blowdown turbine condition
blowdown 'pulses' drive the turbine, the mean exhaust pressure is not raised relative to the induction pressure (it can fall)
backpressure means the mean exhaust pressure is higher than the induction pressure, this is called pressure turbine condition
(the exhaust valve motions of course isolate the combustion chamber from the backpressure)
agreed our accounting of power may not be straightforward

an earlier post mentions 3.5 bar boost ie 3.5 bar absolute (if that can be believed)
many have calculated that as a turbo engine around only 2 bar abs is needed (the 1988 engines were 'only' 2.5 bar abs)
though I have evidenced the efficiency benefits of backpressure, 3.5 bar does not suggest backpressure any time soon

Regardless of semantics,

1. Pressure inside exhaust manifold will be close to pressure at intake manifold (let's say I:3.0, E:2.5bar) when turbine is powering the compressor. If turbine is turbocompounding (powering the MGUH), probably higher.
2. Pressure inside exhaust manifold will be close to zero if you open a big wastegate. Pumping alone, doing very quick math, will take 20hp less than regular ICE, 40hp less than turbocompounding ICE. That extra power will "go" to the flywheel.
3. Air mass flow can be kept with the MGUH at the same levels. Boost required to keep AMF will be lower, but that's not related to the point.

mgu-k recovery is torque limited by rule so that 161 hp recovery is only allowable over about 5500 crank rpm, below that it falls
surely there will be little or no capacity provided eg in the motor drives to allow higher total power (than this 161 hp) from storage ?

I don't follow. If you mean there is no energy in the batteries to power both MGUK and MGUH consistently during a race in the max power mode, then I fully agree with you. If you mean you can't ever draw 250hp from the batteries, I don't agree. You can for short burst. There is no limit to that, not in the rules, not in the physics, as long as you plan for it.

but the fuel rate regime allows mgu-k generation directly from motor running (eg when the driver can't use a lot of power)
as has always been done with the KERS
this is a relatively tracktime-efficient use of fuel, and surely will be worthwhile at some times and places in 2014 etc ?

Yes.

[OO7]

These claims are made from people having no technical knowledge what so ever!! And its pretty annoying they just write BS like this.

900 hp would mean 740 hp from the ICE alone. Fast calculations tells that this needs a thermal efficiency of 43% with a fuel energy density of 46MJ / KG. This to me seems impossible.

I have no technical background but, when you say its impossible. Do you mean theoretically or physically? This is the first time they have focused on efficiency in F1. Also the turbo and the direct injecting technology could, that not changes things?

I don't mean its impossible as in it can never be done. I just feel like its impossible to take such a huge step in such short time. Gasoline engines have had a thermal efficiency of around 30% for ages. Turbo's, downsizing and direct injection will of course help the efficiency but to go from around 30% to 43% is a giant step. Even the 35% TE needed to create the 600 hp as many here sees as a realistic number is a pretty good improvement.

I think Andy Cowell from Mercedes engine department stated in an interview that 40% efficiency was the target.

[ppj13]

40% peak efficiency, maybe. 40% efficiency at peak power, no, no.

There are two efficiencies, though. The one you calculate if you consider MGUH power delivery, and the one without it.

The one needed to calculate the complete power of the ice at the flywheel MGUK off, MGUH off (600hp) is the lower one. So it is the efficiency of a turbo DI engine for F1. That's the one I see at 35% at peak power, being quite optimistic.

The other one, considering the MGHU harvesting 60hp and sending them to the MGUK, the efficiency of the complete power unit in a bench, (the efficiency of a DI turbocompound engine for F1) I believe could be close to 40% at peak power. That's the one governing how good is the engine during a race.

[dren]

an earlier post mentions 3.5 bar boost ie 3.5 bar absolute (if that can be believed)
many have calculated that as a turbo engine around only 2 bar abs is needed (the 1988 engines were 'only' 2.5 bar abs)
though I have evidenced the efficiency benefits of backpressure, 3.5 bar does not suggest backpressure any time soon

Any thoughts on the exhaust the Mercedes is using and its relation to possible backpressure running?

[mrluke]

1. Pressure inside exhaust manifold will be close to pressure at intake manifold (let's say I:3.0, E:2.5bar) when turbine is powering the compressor. If turbine is turbocompounding (powering the MGUH), probably higher.
2. Pressure inside exhaust manifold will be close to zero if you open a big wastegate. Pumping alone, doing very quick math, will take 20hp less than regular ICE, 40hp less than turbocompounding ICE. That extra power will "go" to the flywheel.
3. Air mass flow can be kept with the MGUH at the same levels. Boost required to keep AMF will be lower, but that's not related to the point.

how can 1. and 2. both be true? A wastegate is not an on/off switch it is a variable control to maintain a "constant" pressure within the manifold. In addition if the pressure within the exhaust manifold went to 0 while the wastegate was open, air would be pushed into the manifold through the wastegate.

[CBeck113]

I think ppj13 is refering to the fact that the wastegate is used as a pressure limiting device in case of a problem with the MGUH, and the pressure difference vs. atmosphere would be 0, not 0 bar pressure absolute.

[Powershift]

Keep it civilised? You're either wrong or you're not. Talking about torque when you mean power is not an opinion. It's simply wrong.

It is you that is wrong, the instantaneous force of the wheel to the track is torque and not power, If you are referring to how long it takes to get down the straight then yes power is what needs to be known(as long as the torque doesn't have you wheel spinning the whole time), but it is the torque of the system that determines if there is wheelspin or not.

At the start of a drag strip where dragsters can develop enough torque to flip the cars, the road takes much more of a beating than at the end of the 1/4 mile when the engines are producing far more horsepower.

Listen to Hamilton explain the feeling with the much higher torque produced by these PU's.

[Holm86]

an earlier post mentions 3.5 bar boost ie 3.5 bar absolute (if that can be believed)
many have calculated that as a turbo engine around only 2 bar abs is needed (the 1988 engines were 'only' 2.5 bar abs)
though I have evidenced the efficiency benefits of backpressure, 3.5 bar does not suggest backpressure any time soon

3.5 bar boost typically refers to 3.5 bar above atmospheric. i.e. 4.5 bar abs.

This becomes obvious when you talk about an engine running 0.5 bar boost, it is not being feed with lower than atmos pressure air.

As far as I understand it the mgu-h generates power by braking the turbo and thus controlling boost. This is going to cause higher back pressure pre turbo than in a traditional setup where the excess boost is bled out of the system via a wastegate. Clearly there must be a limit on how much load the turbine can deal with before a wastegate will need to open.

Feel free to correct If i have misunderstood.

I calculated the boost to be 1.25 (2.25 absolute) bars of boost @ 10.500 rpm falling to 0.6 (1.6 absolute) bars of boost @ 15.000 rpm. This was based on a static temperature and a stoichiometric air fuel ratio.

[Holm86]

I have no technical background but, when you say its impossible. Do you mean theoretically or physically? This is the first time they have focused on efficiency in F1. Also the turbo and the direct injecting technology could, that not changes things?

I don't mean its impossible as in it can never be done. I just feel like its impossible to take such a huge step in such short time. Gasoline engines have had a thermal efficiency of around 30% for ages. Turbo's, downsizing and direct injection will of course help the efficiency but to go from around 30% to 43% is a giant step. Even the 35% TE needed to create the 600 hp as many here sees as a realistic number is a pretty good improvement.

I think Andy Cowell from Mercedes engine department stated in an interview that 40% efficiency was the target.

This is compounded efficiency where you calculate the total output of the ICE and MGU's. Right now we are talking about the ICE isolated.

[Holm86]

Fascinating read guys thanks a lot.
Is it possible some people have underestimated just how much work has gone into efficency of the engine- Mercedes in particular.
I have read an article about Honda's new engine for f1 and there aim is for as close to 40% efficiency as they can
Surely the current engines must be similar and also aren't there fancy new fuels being used/developed by the teams?

People need to remember we are looking at the ICE isolated here.

And when we are looking at that isolated we will see an engine that is not very different from an engine 20 or 30 years ago. The "only" new technologies on these engines are direct injection and turbos. Roadcars have been driving around with those technologies the past few years. And their TE% are not 40%. We can suspect that these F1 engines run higher compression ratios than roadcars which would increase TE% slightly. And then there are modern coating technologies to reduce friction and heat transfer within the engine. Also remember stuff like variable valve control is prohibited on these new F1 engines. This is something almost every roadcar is using today. Even the cheapest models.

And I don't care how many recourses Mercedes has put into their engine development. You just don't go from about 30% TE to over 40% TE in 2 years. If is was that easy the manufactures would have done the same with roadcar engines already.

[chrispphunt]

This was the article I was reading-

http://uk.mobile.reuters.com/article/id ... 6?irpc=932
he is talking purely of the 'gasoline engine' which is what got me wondering.
Seems unlikely as it would be such a big jump but surely he wouldn't say such things if it wasn't a realistic target.

[Holm86]

This was the article I was reading-

http://uk.mobile.reuters.com/article/id ... 6?irpc=932
he is talking purely of the 'gasoline engine' which is what got me wondering.
Seems unlikely as it would be such a big jump but surely he wouldn't say such things if it wasn't a realistic target.

Thanks for the article. I'll read this later

[PhilS13]

This was the article I was reading-

http://uk.mobile.reuters.com/article/id ... 6?irpc=932
he is talking purely of the 'gasoline engine' which is what got me wondering.
Seems unlikely as it would be such a big jump but surely he wouldn't say such things if it wasn't a realistic target.

You just need to read that part to know the person who wrote the article has no clue :

Even the best of today's most advanced gasoline engines use only 30 percent of the thermal energy they create by combustion. The rest is wasted during braking and leaks out through exhaust pipes as heat. Arai wants to improve that thermal efficiency to as much as 40 percent

Engine thermal efficiency numbers and braking ? Err. No.

To me the 40% figure has always been with MGU-H because it IS the actual efficiency of the unit as a whole. Doesn't matter if the power comes from the actual combustion itself or from the turbine converted to electricity then back in mechanical via the flywheel. The only power source of that system is the fuel.

[PABLOEING]

This is not F1

http://www.youtube.com/watch?v=jS4Dh_EAfJI