Mercedes Power Unit Hardware & Software

[godlameroso]

Another tidbit I forgot to bring up is that the boost pressures have increased this year to the point that Racing Point suffered failures of their CFRP compressor outlet pipe earlier in the season. It is understood Williams and Mercedes were already running metallic outlet pipes.

At a coupler or pipe itself? So around 5.5 bar absolute?

Dunno, how did you come up with that number ?

Experience with silicon couplers.

[63l8qrrfy6]

All I know is that the carbon fibre outlet pipe burst, not sure how you got to that.

[PlatinumZealot]

@godlameroso The Mercedes compressor outlet has a slanted cut to it and in some models you see a bolted carbonfibre flange with outlet peice on it. Some models you see a metal outlet piece.

Carbon fibre reinforceed plastic is strong.. But heat destabilizes it. The compressor outlet temoerature increase with increased boost pressure. As a pressured pipe the outlet peice would have been tested at at least 150% more pressure than typical operation. It tells me higher temperatures from increased boost was caused the problem.

[63l8qrrfy6]

@godlameroso The Mercedes compressor outlet has a slanted cut to it and in some models you see a bolted carbonfibre flange with outlet peice on it. Some models you see a metal outlet piece.

Carbon fibre reinforceed plastic is strong.. But heat destabilizes it. The compressor outlet temoerature increase with increased boost pressure. As a pressured pipe the outlet peice would have been tested at at least 150% more pressure than typical operation. It tells me higher temperatures from increased boost was caused the problem.

Yes, he mentioned they test them hydraulically at high pressures. So I think you are right, the issue is probably the temperature. So maybe we can work back from the glass transition temperature of a typical resin, assume that is the compressor outlet temperature and estimate the pressure ratio.

Edit - had a go at it:

Very high Tg prepregs go up to 310°C - the equivalent compressor PR would be in excess of 7!
More standard prepregs have a Tg of ~260°C - the equivalent PR is somewhere around 5.5 (lucky guess godlameroso)

I assumed 300K (27°C) inlet temp and 0.8 compressor efficiency.

Edit 2 - I am being informed it is not unusual to operate above Tg so maybe we can't read too much into it.

[godlameroso]

It's not the pipe itself, it's always the joints that lead to failures, just like our weak human bodies, if they're rigid joints they can induce harmonics in the pipes accelerating their demise. If they're flex joints then they need to be beefy, silicon couplers will blow out at ~4.5 bar. If they're using band clamps on CFRP then they should have known this would happen because it's stiffer than metal.

[63l8qrrfy6]

It's not the pipe itself, it's always the joints that lead to failures, just like our weak human bodies, if they're rigid joints they can induce harmonics in the pipes accelerating their demise. If they're flex joints then they need to be beefy, silicon couplers will blow out at ~4.5 bar. If they're using band clamps on CFRP then they should have known this would happen because it's stiffer than metal.

They have a bolted connection. I'll dig out pictures tomorrow unless someone beats me to it.

[godlameroso]

It's not the pipe itself, it's always the joints that lead to failures, just like our weak human bodies, if they're rigid joints they can induce harmonics in the pipes accelerating their demise. If they're flex joints then they need to be beefy, silicon couplers will blow out at ~4.5 bar. If they're using band clamps on CFRP then they should have known this would happen because it's stiffer than metal.

They have a bolted connection. I'll dig out pictures tomorrow unless someone beats me to it.

I'll take your word for it, then it's obvious why it happened.

[63l8qrrfy6]

There you go, the red blanking plate is where the pipe normally goes. Bolt bosses are easily distinguishable.
I can't find any pictures of the actual pipe though and I can't remember seeing one, maybe PZ can help?

[NL_Fer]

0,3s gained in Q3.

They must have found a way to administer their illegal partymode substance without the use of a ECU mapping.

[63l8qrrfy6]

0,3s gained in Q3.

They must have found a way to administer their illegal partymode substance without the use of a ECU mapping.

I doubt that's the case but I believe it's something easy to do and difficult to prove.

[tangodjango]

0,3s gained in Q3.

They must have found a way to administer their illegal partymode substance without the use of a ECU mapping.

How did Hamilton lose time then?

[godlameroso]

0,3s gained in Q3.

They must have found a way to administer their illegal partymode substance without the use of a ECU mapping.

How did Hamilton lose time then?

Exit of turn 4, the space between 10 and 11, and the chicane. Hamilton carried more speed through it but Bottas had a better exit arriving sooner to the final corner. Bottas gained .134 on Verstappen on that corner alone. It's very difficult to nail the space between 10 and 11, I think Bottas just lucked into being fast in that part of the track.

Cars driving over the track and the patchy sunshine made track temperature inconsistent along with grip, plus the drop in wind hurt cars on the hairpin and final corner.

[PlatinumZealot]

There you go, the red blanking plate is where the pipe normally goes. Bolt bosses are easily distinguishable.
I can't find any pictures of the actual pipe though and I can't remember seeing one, maybe PZ can help?

https://ibb.co/bQGmndP

I found the 2014 design.

[63l8qrrfy6]

There you go, the red blanking plate is where the pipe normally goes. Bolt bosses are easily distinguishable.
I can't find any pictures of the actual pipe though and I can't remember seeing one, maybe PZ can help?

https://ibb.co/bQGmndP

I found the 2014 design.

Nice find, interesting solution.
I wonder why the aluminium section is required. Maybe to achieve o ring groove surface finish which you can't normally get on carbon fibre composites ?

[zibby43]

Q3 times before/after engine mode restrictions



courtesy of /u/Zeurpiet on /r/formula1