Why does the Mercedes engine sound different?

[toraabe]

Remember that this is just testing. NOT the spec that they will use in race.

[WaikeCU]

Sector one, why would they use an old engine and exhaust in a shakedown run?

I think because it's running at quite a high speed. Usually a shakedown is a systems check roll out running up and down the gears and box. By using the old engine and exhaust there's already that confidence that reliability wouldn't be an issue, so running at true pace wouldn't be a problem. The upside would be at day 00 there's already true data on the level of aero and mechanical grip of the new car. So at day 01 of Jerez testing, they would already have some data on mechanical grip and aerodynamical grip levels. Downside would be: what difference would the new PU bring?

Unless they really ran the old PU formula per se, then the rumours might be true on Mercedes running the 2014 PU formula at the start of the 2015 season.

[F1SC]

This doesn't sound like the 2014 PU though.

Mercedes haven't used the tubular style manifold since Jerez 2014 at which point they got rid of it and used the log style for the entire season (see my videos in the first post).

Wait and see but it seems they have reverted back for what ever reason.

[mrluke]

The Ferraris have the wastegate open much more than the Mercedes which is part of the reason they sound better at high rpm

[SectorOne]

Sector one, why would they use an old engine and exhaust in a shakedown run?

No idea, maybe it´s just easier, dunk that engine in just to do the filming day.
I´m almost certainly wrong though.

So i guess they went back to the old exhaust after running a whole season with the log type which produces a vastly different sound then what we heard in the 2015 video.

[F1SC]

Well this is interesting - it seems Honda has gone for a similar log type setup that Mercedes used last year, whilst the Mercedes now sounds like the Renaults and Ferrari's.

Go to 1:50 for the Honda sound - exactly the same note as the 2014 Mercedes PU

https://www.youtube.com/watch?v=lfkkxWGkxck

[wuzak]

Well this is interesting - it seems Honda has gone for a similar log type setup that Mercedes used last year, whilst the Mercedes now sounds like the Renaults and Ferrari's.

Go to 1:50 for the Honda sound - exactly the same note as the 2014 Mercedes PU

https://www.youtube.com/watch?v=lfkkxWGkxck

I don't think you can conclude that as the Honda does not sound like it is running at all correctly.

[Richard]

Maybe because some MB are diesel powered? I don't know but that's my take on the topic.

PML - So that's the secret of the mysterious Petronas fuel!

[ojlopez]

Well this is interesting - it seems Honda has gone for a similar log type setup that Mercedes used last year, whilst the Mercedes now sounds like the Renaults and Ferrari's.

Go to 1:50 for the Honda sound - exactly the same note as the 2014 Mercedes PU

https://www.youtube.com/watch?v=lfkkxWGkxck

I don't think you can conclude that as the Honda does not sound like it is running at all correctly.

Yeah, there is some fluttering in the exhaust note.

[F1SC]

For whoever is interested Honda are running the log type exhaust system and wow does it sound mean! This video just in from Jerez!

[gruntguru]

It sounds like they might have paid some attention to enhancing the exhaust sound.

[J.A.W.]

Yeah, maybe they were using an old Honda six like this - as an aural yardstick..

https://www.youtube.com/watch?v=fssM1FyUvfo

[pgfpro]

It sounds like they might have paid some attention to enhancing the exhaust sound.

Something is up!!!

They sure don't sound like last years engine on deceleration?

I'm still trying to figure out what their doing???

[gruntguru]

Yes something unusual is going on there. The part throttle cylinder-skipping is very obvious from 4 sec to 7 sec, then an abrupt change in note as it goes onto 6 cylinders from 7 sec to 9 sec.

From 9 sec onwards the decel sound is actually quite loud - almost like a compression brake on a truck. Most likely they are opening the waste gate on decel - perhaps this reduces parasitic drag in the turbine and so consumes less energy for the MGUH to keep the turbo spinning?

[dren]

Less engine braking, more MGUK brake recovery?