Mercedes Power Unit Hardware & Software

[basti313]

The split turbo solution looks so logical now, can’t think of a single big advantage to have the Renault or Ferrari solution.

Absolutely. I am thinking how much of the benefit is actually on the intercooler...having the compressor not at the exhaust turbine should keep the compressor way colder. Already some 5-10°would have a well noticeable effect on the intercooler.

[Zynerji]

The split turbo solution looks so logical now, can’t think of a single big advantage to have the Renault or Ferrari solution.

Absolutely. I am thinking how much of the benefit is actually on the intercooler...having the compressor not at the exhaust turbine should keep the compressor way colder. Already some 5-10°would have a well noticeable effect on the intercooler.

A turbo directly feeding an intake manifold that has integrated vortex tubes could theoretically drop the intake air to sub-zero Temps.

It would waste boost pressure, as 40-50% would bleed out the hot end of the tube (blowoff valve/turbine feedback), but even at 50% boost, the density increase from temperature drop may well overcome the losses.

Or not.

[henry]

The split turbo solution looks so logical now, can’t think of a single big advantage to have the Renault or Ferrari solution.

Absolutely. I am thinking how much of the benefit is actually on the intercooler...having the compressor not at the exhaust turbine should keep the compressor way colder. Already some 5-10°would have a well noticeable effect on the intercooler.

A turbo directly feeding an intake manifold that has integrated vortex tubes could theoretically drop the intake air to sub-zero Temps.

It would waste boost pressure, as 40-50% would bleed out the hot end of the tube (blowoff valve/turbine feedback), but even at 50% boost, the density increase from temperature drop may well overcome the losses.

Or not.

Probably not. The blowoff feeds back into the inlet to the compressor, any air that enters the compressor must leave by the exhaust. The plenum has to be at least 10°C above ambient by regulation.

[Zynerji]

Absolutely. I am thinking how much of the benefit is actually on the intercooler...having the compressor not at the exhaust turbine should keep the compressor way colder. Already some 5-10°would have a well noticeable effect on the intercooler.

A turbo directly feeding an intake manifold that has integrated vortex tubes could theoretically drop the intake air to sub-zero Temps.

It would waste boost pressure, as 40-50% would bleed out the hot end of the tube (blowoff valve/turbine feedback), but even at 50% boost, the density increase from temperature drop may well overcome the losses.

Or not.

Probably not. The blowoff feeds back into the inlet to the compressor, any air that enters the compressor must leave by the exhaust. The plenum has to be at least 10°C above ambient by regulation.

The hot side could dump directly into the exhaust turbine, then out of the exhaust. Then it doesn't need to recirculate into the compressor.

Plenum is before the turbo, so this shouldnt matter. This would be IAT.

Wait... Is it airbox plenum, or intake plenum that needs to be +10? If airbox plenum, either turbo or intake runners could be used. If it's the intake plenum, the intake runners could still be used to this effect.

In an unlimited formula, sub-zero intake air charges could lead to 50:1 compression ratios, as the work required to compress the charge drops dramatically. It could be nuts.

[saviour stivala]

5.6.8. Engine plenum (as defined in line 4 of appendix 2 to these regulations) air temperature must be more than ten degrees centigrade above ambient temperature.

[henry]

A turbo directly feeding an intake manifold that has integrated vortex tubes could theoretically drop the intake air to sub-zero Temps.

It would waste boost pressure, as 40-50% would bleed out the hot end of the tube (blowoff valve/turbine feedback), but even at 50% boost, the density increase from temperature drop may well overcome the losses.

Or not.

Probably not. The blowoff feeds back into the inlet to the compressor, any air that enters the compressor must leave by the exhaust. The plenum has to be at least 10°C above ambient by regulation.

The hot side could dump directly into the exhaust turbine, then out of the exhaust. Then it doesn't need to recirculate into the compressor.

Plenum is before the turbo, so this shouldnt matter. This would be IAT.

Wait... Is it airbox plenum, or intake plenum that needs to be +10? If airbox plenum, either turbo or intake runners could be used. If it's the intake plenum, the intake runners could still be used to this effect.

In an unlimited formula, sub-zero intake air charges could lead to 50:1 compression ratios, as the work required to compress the charge drops dramatically. It could be nuts.

The plenum is:

PU Engine air inlet system from Engine plenum entry to cylinder head (e.g. plenum, trumpets, throttles)

You can’t route intake air to the exhaust because of:

5.2.12 With the exception of incidental leakage through joints (either into or out of the system) all and only the air entering the compressor inlet must enter the combustion chambers.

[Zynerji]

Non-fungible air...

[PlatinumZealot]

The inlets for the mguh infront of the compressor usually are very large to compensate for the energy losses to. You see very wide bean-shaped inlets pointing upward to allow space to initiate the swirling motion.

I even wonder if those configurations manage to fit a variable vaned inlet?

If you mean the guide vanes directly ahead of the compressor inlet, the Mercedes certainly has these. I think they're used for "throttling" and there's a picture somewhere showing the Mercedes installation.

Oh i know of mercedes and Honda. There are photos showing it direct too. Meant for Ferrari.

[OO7]

Oh i know of mercedes and Honda. There are photos showing it direct too. Meant for Ferrari.

I did wonder, because it's not like you to miss something like that.

[OO7]

A couple of development ideas I had about the Mercedes. I'm know very little about engines and MGUs, so this idea could be way off.

Looking at designs from Honda, Renault and Ferrari they all have narrower plenum chambers in comparison to Mercedes, leading to a narrower engine cover and better air flow to the rear wing.
Mudflap provided us with some intel stating that due to "...a new intake concept...", "...the engine cover will have to be compromised slightly to accommodate it". This is one area I've always looked at (since 2015) and thought Mercedes could work on slimming, to bring its packaging inline with the other PU manufacturers, clearly the cost in performance would be too great.

Another area I've thought Mercedes could develop further, is the shaping of the main, sidepod radiators. I've been thinking of a design akin to the example Williams exploited maybe 2 or 3 years ago shown below:

Embracing the 'twist' could help by bringing the rearmost part of the radiator closer to the monocoque, leading to a narrower section and hopefully increased airflow.

Now the following stems the fact that the MGU-H needn't reside in the middle of the shaft and can be placed to one end as shown below:

I had asked in a different thread about the size of the MGU-H, as I wanted to know how much length within the 'V' it occupied, as well as the possibility of relocating the oil/scavenge pump. The above image of the Mercedes MGU-H appeared a few days later coincidentally, so that was very helpful.

Move the oil/scavenge pump to the front of the engine, place the MGU-K in the 'V' with the MGU-H, but design the centre of the MGU-K allow the 'H's' shaft to run through it to the turbine. This would be in a similar fashion as how jet engine spools are mechanically independent and how one spool is mechanically connected to a gearbox to drive accessories (Essentially the MGU-K to crankshaft connection). This repackaging would free up the lower flanks of the engine. The following image is of the 2018 Mercedes PU:

We can see in the picture that the rear most exhaust manifold loops up slightly above the height of the engine bracing bar. With the repackaged ICE, the manifolds could be brought closer to the block, allowing manifold to be place almost underneath rather than beside each bank. This configuration should allow for a tighter coke bottle and enhanced airflow over the rear floor and diffuser. The compromise would be a taller CoG and redesigning/repackaging the front of the engine.

So the question is, would this be possible and would it be beneficial?

[Morteza]

“We’ve completed some work on improving the reliability of the PU,” he said. “In 2020, we used an aluminium structure which wasn’t as reliable as intended, so we’ve introduced a new alloy for the engine block.

“We’ve also made some adjustments to the Energy Recovery System, to make it more resilient. We’ve got a big challenge in 2021 with 23 races on the calendar, we will need to ensure that the reliability of the power unit is spot on. We’ve worked hard on that area and hopefully it’s paid off.”

“We introduced a complete redesign in 2020, a very different MGU-K to what we had run previously,” added Thomas. “It helped us make a solid step forwards in performance, but it was a design that turned out to be difficult to manufacture and assemble consistently.

“We had lots of examples where the MGU-K ran a full cycle and did exactly what we wanted it to do, but we also had some cases of midlife failures. For 2021, we’ve gone back, looked at that design and built an understanding of where the failures have come from.

“We have changed it for this year, to allow for a more consistent manufacturing route which should help to improve the reliability of the MGU-K.”

“We’ve got some completely new innovations that will be in the racing PU for the first time,” he said.

“That was particularly challenging because last season finished late, so the winter period has been shorter than normal and has given us less time to prepare, which put extra strain on the business.”

He added: “We’ve continued our quest for better thermal efficiency in the internal combustion engine. Most of the developments can be found in the core of the power unit, with a desire for maximum output from the combustion process.

“Hand in hand with that, we’ve introduced changes to the turbocharger to minimise the impact on the heat rejection. Those are probably the most striking when it comes to crank power and the performance of the power unit.”

[aleks_ader]

Move the oil/scavenge pump to the front of the engine, place the MGU-K in the 'V' with the MGU-H, but design the centre of the MGU-K allow the 'H's' shaft to run through it to the turbine. This would be in a similar fashion as how jet engine spools are mechanically independent and how one spool is mechanically connected to a gearbox to drive accessories (Essentially the MGU-K to crankshaft connection). This repackaging would free up the lower flanks of the engine. The following image is of the 2018 Mercedes PU:

So the question is, would this be possible and would it be beneficial?

Yeah u stole mine though from years ago. I was in same tought process. IDK. Potencial is there i think. Especially beacuse the MINIMUM CoFg is defined in rules. And penalty should not be big. At least u got battery and intercooler low down and infront engine.

Also Shenanigans with MGUH and MGHUK connections could be exploitable (indirectly ofc).

[Jolle]

A couple of development ideas I had about the Mercedes. I'm know very little about engines and MGUs, so this idea could be way off.

Looking at designs from Honda, Renault and Ferrari they all have narrower plenum chambers in comparison to Mercedes, leading to a narrower engine cover and better air flow to the rear wing.
Mudflap provided us with some intel stating that due to "...a new intake concept...", "...the engine cover will have to be compromised slightly to accommodate it". This is one area I've always looked at (since 2015) and thought Mercedes could work on slimming, to bring its packaging inline with the other PU manufacturers, clearly the cost in performance would be too great.

Another area I've thought Mercedes could develop further, is the shaping of the main, sidepod radiators. I've been thinking of a design akin to the example Williams exploited maybe 2 or 3 years ago shown below:
https://pbs.twimg.com/media/EALnGbkXUAAKEay.jpg
Embracing the 'twist' could help by bringing the rearmost part of the radiator closer to the monocoque, leading to a narrower section and hopefully increased airflow.

Now the following stems the fact that the MGU-H needn't reside in the middle of the shaft and can be placed to one end as shown below:
https://i.imgur.com/wONrgx9.jpg
I had asked in a different thread about the size of the MGU-H, as I wanted to know how much length within the 'V' it occupied, as well as the possibility of relocating the oil/scavenge pump. The above image of the Mercedes MGU-H appeared a few days later coincidentally, so that was very helpful.

Move the oil/scavenge pump to the front of the engine, place the MGU-K in the 'V' with the MGU-H, but design the centre of the MGU-K allow the 'H's' shaft to run through it to the turbine. This would be in a similar fashion as how jet engine spools are mechanically independent and how one spool is mechanically connected to a gearbox to drive accessories (Essentially the MGU-K to crankshaft connection). This repackaging would free up the lower flanks of the engine. The following image is of the 2018 Mercedes PU:
https://i.imgur.com/HFdaeWG.png
We can see in the picture that the rear most exhaust manifold loops up slightly above the height of the engine bracing bar. With the repackaged ICE, the manifolds could be brought closer to the block, allowing manifold to be place almost underneath rather than beside each bank. This configuration should allow for a tighter coke bottle and enhanced airflow over the rear floor and diffuser. The compromise would be a taller CoG and redesigning/repackaging the front of the engine.

So the question is, would this be possible and would it be beneficial?

Anything would be possible, but moving the K behind the H would land you in a new heap of complications. Other then the compexaty of having it build around a shaft, there has to be a connection to the crank that. This would mean extra space at the rear, making the H shaft even longer and the whole thing heavier. Cog is of course an issue. Electric motors are dense and heavy. The extra gears, bearings, etc sit in the wrong side of the COG (above it).

The space where the K unit is now, is a bit of dead space. The bottom of the car has a minimum width and there is a nice area below the spaghetti exhausts. This would otherwise be used for less heavy equipment (such as liquids, sensors or wires). Even if this wasn’t the case they wanted the K unit there gone, straight forward before the engine would make more sense. Surrounded by the battery and below the fuel tank.

[PlatinumZealot]

I got word that Mercedes have been developing a new intake concept for the last year which will be ready for the start of 2021 and is expected to bring a good step in performance.

The new architecture will be visibly different and the engine cover will have to be compromised slightly to accommodate it but the aero loss is said to be small compared to the power gained.

Yes, Mudflap. I had to break some rules, but thanks for keeping it on the down-low for me, pal.

Heheh..

Kidding.

Very spot on!

I am taking a wild guess and saying they have shifted the inter-cooler package upward, thus having to invert the "T" shape to the chassis. They can extend the intake the compressor this way... Just a wild guess though. Have to wait till the races.

[ispano6]

“We’ve completed some work on improving the reliability of the PU,” he said. “In 2020, we used an aluminium structure which wasn’t as reliable as intended, so we’ve introduced a new alloy for the engine block.

...

A new alloy? Curious to see if it's similar to what Honda introduced last year...