Mclaren Mercedes MP4-25

[marcush.]

so Macs also have the Renault type DDD feed..

the outer difusser feet are not connected to the underfloor?

[BreezyRacer]

Based on the temp paint locations it seems to me that they are trying to see if the exhaust is being pulled into the diffuser cavity via the split in the floor alongside the rear tire. The front of that little section of the floor humps up as an inlet. I wonder if one of the things they want to test is to block off that inlet to see if what they are trying is working.

Also, maybe it's just the pic but the inlet of the diffuser looks confusing to me, like it wouldn't flow too well in comparison to the RB and Ferrari designs. The entry looks turbulent. Maybe a better angle will tell more .. hope we get another shot or two. Thanks Lewis!

That pic also nicely shows the splitter deflectors at the front of the splitter, which all teams seem to be going to. Renault was first with that I think. Notice how they try to deflect undertray airflow out to the sides. Meanwhile there is a small inlet at the front of the inlet to feed airflow along the stepped area of the floor.

[wesley123]

duuuuude, those DDD inlets are simply Huuuuuuge, much larger then others it seems.

Someone told that the holes are regulated by the suspension arms, so bringing giving then an large angle brings the front pickup points further forward, allowing an larger intake, but now when seeing this this intake is the mother of all intakes lol, seems so much larger and even more holes.

To compare them to renault the mclaren seems to have 2 of such holes thus it is even larger.

This made me thinking, could this be he reason the mclaren running so stiff? When the bodywqork gets too low you simply choke those holes thus reducing the downforce.

[BreezyRacer]

Well as for ride heights they all have the same 50 mm step to contend with. The most important thing in these designs to minimize turbulent flow and maybe it's just the camera angle but there seems to be some funky goings on at the beginning of the port. I'm still reserving judgments but a few things about the diffuser look questionable. Why extend the strakes into the inlet area? And now they have trimmed the outer strakes, but why have them at all. They only increase the chance for turbulence at that height. Lastly the outsides of the diffuser open up pretty radically which is good IF it doesn't cause turbulence. Maybe they are thinking the exhaust will help there, I don't know. In general it seems like they are trying to force the airflow around too much ..

[wesley123]

Well as for ride heights they all have the same 50 mm step to contend with. The most important thing in these designs to minimize turbulent flow and maybe it's just the camera angle but there seems to be some funky goings on at the beginning of the port. I'm still reserving judgments but a few things about the diffuser look questionable. Why extend the strakes into the inlet area? And now they have trimmed the outer strakes, but why have them at all. They only increase the chance for turbulence at that height. Lastly the outsides of the diffuser open up pretty radically which is good IF it doesn't cause turbulence. Maybe they are thinking the exhaust will help there, I don't know. In general it seems like they are trying to force the airflow around too much ..

Indeed but the car seems to have such gills oput of that box, thus in the floor itself, there is an simple cover over those holes just like renault. There is such thing as the flat bottom rule, but it is still an flat bottom in this case as there are no bends in it, only holes, and the parts masking that are only per regulations if im correct.

[BreezyRacer]

Well as for ride heights they all have the same 50 mm step to contend with. The most important thing in these designs to minimize turbulent flow and maybe it's just the camera angle but there seems to be some funky goings on at the beginning of the port. I'm still reserving judgments but a few things about the diffuser look questionable. Why extend the strakes into the inlet area? And now they have trimmed the outer strakes, but why have them at all. They only increase the chance for turbulence at that height. Lastly the outsides of the diffuser open up pretty radically which is good IF it doesn't cause turbulence. Maybe they are thinking the exhaust will help there, I don't know. In general it seems like they are trying to force the airflow around too much ..

Indeed but the car seems to have such gills oput of that box, thus in the floor itself, there is an simple cover over those holes just like renault. There is such thing as the flat bottom rule, but it is still an flat bottom in this case as there are no bends in it, only holes, and the parts masking that are only per regulations if im correct.

I agree .. according to my understanding of the rules this open bottom of the port doesn't seem legal but I cannot imagine McLaren not having a legal clarification on it.

As to effectiveness of the design, I don't think they are doing themselves any favors with the open port. Imagine how much turbulence could be created along the length of the inlet under different yaws and heights. Your observation in regards to ride height is very relevant to this as the flow patterns could conceivably change quite a bit. The Ferrari and Red Bull design is immune to this variation since the inlet configuration is consistent with ride height change. Even the Renault design is flush with the bottom of the sidepods so it would be pretty consistent too. Those inlet humps behind the inlet on this design however would seem to introduce a lot of variances in flow in relation to ride height, much less taking into account yaw angles. Of course all this is, again, based on just this one photo.

It's almost as if the design was based on the idea of airflow PUSHING into the diffuser instead of airflow being PULLED by the diffuser. It may seem a subtle difference to some but it is not.

[wesley123]

indeed, and what i can think off is that this is the reason why mclaren is running their cars so stiff, they have to keep the ride height or else the diffuser will 'choke' as there is effectively less air to enter through the holes.

Just like always, every good idea has its bad things.

And about the clarification, it is just usual bussiness to do so, making the parts illegal in some way but their clarification makes it legal again.

But those holes are legal, if im correct the floor itself is the reference plane, any bodywork above the plane must not be seen, else it is illegal. That is why these covers are there, same as renault, these are covers to cover the above bodywork, and These covers arent regulated as 'above' bodywork because they are in between the 5 cm higher step plane, hence this design is again driven by loopholes, but the design is in no way illegal, and it cannot be discussed about if it is legal or not, as it IS legal due to explained above. It is an smart move and we might even see this return next year as to work around the DDD ban.

[AbbaleRacing77]

The axle just falls out when the A arms are broke. There is a tripod bearing at the end of each axle that loosely sits in a coupler at the gearbox. Therefore it didnt cause any damage to the gearbox. And the a arms being ripped off and damaging the gearbox isn't true either. The A-arm bolts are designed to break before the gearbox does.

[PlatinumZealot]

Looks like the renault for real. I still think the redbull is the biggest of all diffusers though the mclaren looks almost there.

You guys notice that some parts of the diffuser is foam filled. Looks like regular house foam but I i bet it's not.

I am a little confused with the front splitter. That looks like two diffusers up the front on either side of the splitter. why did they use a divergence instead of a nozzle?

[wesley123]

That foam sits there because of the use of the fire extinguiser by the marshalls, it is just common practice to spray some on the damaged part, as it is most likely to get an fire out of there.

And the diffuser entry imo is even bigger as it uses the floor itself too, thats why those 2 parts are there, to mask the bodywork above.

But those holes are legal, if im correct the floor itself is the reference plane, any bodywork above the plane must not be seen, else it is illegal. That is why these covers are there, same as renault, these are covers to cover the above bodywork, and These covers arent regulated as 'above' bodywork because they are in between the 5 cm higher step plane, hence this design is again driven by loopholes, but the design is in no way illegal, and it cannot be discussed about if it is legal or not, as it IS legal due to explained above. It is an smart move and we might even see this return next year as to work around the DDD ban.

[astracrazy]

mclaren have a new rear wing as well? or have they used it before...

seems there is a slot under the f-duct connection. Like monaco last year really



i see it on the bbc but can't find a decent pic

[feynman]

That foam sits there because of the use of the fire extinguiser by the marshalls, it is just common practice to spray some on the damaged part, as it is most likely to get an fire out of there.

Au contraire, mon ami: The foam sits there because the components are made from foam, sandwiched inside carbon-fibre. Foam is standard practice, but there are lots of other exotic products, depending on requirements, that you can stuff inside your carbon-fibre constructions, here's some:

http://www.acp-composites.com/home.php?cat=256

There were no fire-extinguishers (which are usually powder anyway, ref: that great powdery shot of Petrov's Renault diffuser).
Big panel constructions like rear-wing endplates have been made like this for ages, first time I've seen the foamy inside of a diffuser.

[ringo]

It's not like the renault. The renault has horizontal plates. This one has strakes.


Revealing it doesn't hurt, no team in their right mind is going to sit down and reverse engineer this mess half way into the season. Worst next year DDD will be illegal.
The funny this with this design, is that there really is no first deck diffuser. It's like an upper deck, with a "jaw" for the first deck.

[Pup]

High res pic showing the exhaust as it's run...

http://motorsport.nextgen-auto.com/gall ... -1/048.jpg

Carbon bodywork extension, exhaust extending just shy of the lower wishbone, with what looks to me like a spiral-cut exhaust tip.

And I see that the mechanics wear rocket-red underwear.

[wesley123]

we will see such things next year too, even with the ban of the DDD it is possible. Simply not make it part of the diffuser itself, let it start sooner etc.

The car has holes in the floor itself, and those gills are to mask bodywork above, these gills arent the bodywork above because it fits in the step plane radius. The floor itself is still flat so that rule isnt broken either. I would love to see the rules banning the DDD, as there are probably a million work arounds to still use such device.