Mercedes Power Unit Hardware & Software

[seventhsin]

Almost certainly cooling one would think, the white joint would be for disassembly, thermal expansion and vibration absorbtion.
There could be a radiator up near the roll hoop and the pipe transfers fluid, although I would have thought this isn't very good for the cars COG.

The structural studs are relatively small M12 metric studs. 6 connecting the engine to the chassis, usually found at the front of the cam cover and the bottom of the block. I think the gearbox has 4 studs connecting it to the rear of the engine, can't quite find the regulation right now.

Edit : 6 studs each side of the PU

5.3.6 Power unit mountings may only comprise six M12 studs for connection to the survival cell and
six M12 studs for connection to the transmission.

[GrandAxe]

Just speculation as always...

Hey, that's what I love about this site. None of us 100% know what's going on, but there are plenty of very insightful educated guesses.
I'm all for a 'creative interpretation' of the rules, and I dare say using the alternator as a tricky second K was explored pre the PU era, but I can't see any reason to pursue it now, mainly because I don't think they have one. Just my opinion of course, and as I said, I'm happy to be proven wrong...

An alternator can be used to directly drive the MGU-H. The rules only put a limit on mechanical connections to the H.

[roon]

Quite a cool picture posted by MtthsMlw in the Force India thread, which I thought was good to share in this thread as well. What is the carbon pipe from the gearbox towards the air box? Is it for venting / cooling? It is not a structural stud is it? I suppose the white part is flexible to make sure it is not cracking under deformation?

High res engine and gearbox
https://i.imgur.com/KpdfsvC.jpg

Air duct, likely connecting to the similarly sized hole beneath the role hoop.

There are similarly sized ducts on the opposite side (above the camshaft cover), routed to different locations:

Via AMuS

[henry]

Quite a cool picture posted by MtthsMlw in the Force India thread, which I thought was good to share in this thread as well. What is the carbon pipe from the gearbox towards the air box? Is it for venting / cooling? It is not a structural stud is it? I suppose the white part is flexible to make sure it is not cracking under deformation?

High res engine and gearbox
https://i.imgur.com/KpdfsvC.jpg

The black pipe looks as though it directs cooling air to the wastegate actuators sat on top of the turbine scroll.

Also of note is the convergent-divergent section of the exhaust just before the regulated end section. Is it normal to do that after a turbine?

[roon]

Also of note is the convergent-divergent section of the exhaust just before the regulated end section. Is it normal to do that after a turbine?

In this case I believe it depends upon other hardware in the area. The RW support type, the desired shape of bodywork around the pipe. I think in this case it is the latter, the W08 has an up-down kink in that area which remains circular in cross-section. The VJM09 pipe flattens to oval before resuming to circular; my guess is they don't want a bulge in the engine cover like Merc do on the W08, considering the transmission and the RW support base are shared items.

[henry]

Also of note is the convergent-divergent section of the exhaust just before the regulated end section. Is it normal to do that after a turbine?

In this case I believe it depends upon other hardware in the area. The RW support type, the desired shape of bodywork around the pipe. I think in this case it is the latter, the W08 has an up-down kink in that area which remains circular in cross-section. The VJM09 pipe flattens to oval before resuming to circular; my guess is they don't want a bulge in the engine cover like Merc do on the W08, considering the transmission and the RW support base are shared items.

I think you’re right about the influence of other hardware. Looking again it looks as though the exhaust is shaped to clear the wishbone connection on top of the gearbox and the bodywork above.

[63l8qrrfy6]

Quite a cool picture posted by MtthsMlw in the Force India thread, which I thought was good to share in this thread as well. What is the carbon pipe from the gearbox towards the air box? Is it for venting / cooling? It is not a structural stud is it? I suppose the white part is flexible to make sure it is not cracking under deformation?

High res engine and gearbox
https://i.imgur.com/KpdfsvC.jpg

The black pipe looks as though it directs cooling air to the wastegate actuators sat on top of the turbine scroll.

You sir have a keen eye.
I think it takes air to the duct connected to the gold foil covered actuators which seem to have been relocated this year.
viewtopic.php?f=4&t=23688&start=1725#p787974

[Marble]

Hello everyone,
Small question : on Merc radio, we often hear Bonno talk about "TAG mode" (Tag mode 2 or 3).
I have not seen anything like "TAG" on Merc steering wheel ; could anybody tell me what that "TAG" mode is please ?
Thanks

(And if anyone could tell me if start mode 6 or 5 allows to save fuel compared to strat mode 3 please ? T
Thanks)

[PlatinumZealot]

The driver can tag points on the track by pressing a button and the engineers can review it in the log after the race - or at least this is what I believed over the years...

[Sieper]

So it has nothing to do with user “TAG”? Hard to believe.

[63l8qrrfy6]

The driver can tag points on the track by pressing a button and the engineers can review it in the log after the race - or at least this is what I believed over the years...

You are right - the drivers do have a button for marking various events in the ATLAS data (I suspect this is the telemetry software most if not all of the teams use). This is all available in real time to race engineers.

Whether or not that's what TAG does I don't know.

[Marble]

Thanks everyone for your contribution, but my reckoning is TAG mode is directly linked to performance.

Just 2 examples to illustrate my opinion.

In Australia, lap 21. KR had pitted, Merc responded by pitting Lewis to cover the undercut. He gout out in front of Kimi, and they (mistakenly) thought they had Vettel covered in case of VSC, and then came the message :

Bono : "OK Lewis, you can drop your tag level if we can maintain Vettel’s time. He’s doing a 28.2."

Another example, during the US GP :

PB : "And we can drop to Tag mode 2, tag mode 2."

So I think it's directly linked to performance, but contrary to "Strat" mode, I don't know what this TAG mode is about.

Would you reckon Strat mode 3 is more agressive or less agressive than Strat mode 5 ?

[MtthsMlw]

Would you reckon Strat mode 3 is more agressive or less agressive than Strat mode 5 ?

Strat 3 Race Plus High SOC (0.00)
Strat 5 Race Plus Deploy (0.04)

IMO Strat 5 sounds more powerful.

[Marble]

Would you reckon Strat mode 3 is more agressive or less agressive than Strat mode 5 ?

Strat 3 Race Plus High SOC (0.00)
Strat 5 Race Plus Deploy (0.04)

IMO Strat 5 sounds more powerful.

Yep, would tend to agree.
(Do you know what the number in brackets (0.04) stand for ?

[MtthsMlw]

Would you reckon Strat mode 3 is more agressive or less agressive than Strat mode 5 ?

Strat 3 Race Plus High SOC (0.00)
Strat 5 Race Plus Deploy (0.04)

IMO Strat 5 sounds more powerful.

Yep, would tend to agree.
(Do you know what the number in brackets (0.04) stand for ?

No idea, sorry.