Vodafone McLaren MP4-27 Mercedes

[ajdavison2]

Last time it was just the rears.

[techF1LES]

[JMN]

McLaren hub


Red Bull hub for comparison

[mclaren777]

I saw something weird near the exhaust exit on Button's car during qualifying.

Does anybody have a good picture of that area?

[Owen.C93]

Can't find anything, was he on track and when abouts?

[mclaren777]

I noticed it in Q3 when he was being rolled into the garage. It was on the right side of the car.

[Owen.C93]

I noticed it in Q3 when he was being rolled into the garage. It was on the right side of the car.

That was brake cooling fans and a heat resistant pad to protect mechanics from the hot exhausts.

[gray41]

Anyone noticed any updates so far this weekend?

[Owen.C93]

http://www.youtube.com/watch?v=w-5oE0yq ... age#t=101s

[speedsense]

Almost certainly covering a wire running from a sensor.

If it's a wire then they have one on each side of the wing. Could they be testing different leading edges, with the tape covering a temporary joint?

They've ran these wires at every test session and FP. I think they're pressure sensors.

I don't think they are pressure sensors. If you zoom up very large, you can see the left one (from my view) is a twisted pair that connects to "rib" 1/4 across the wing. Goes from flat wiring (outside end plate) to round twisted pair under the wing.

What is interesting is the right one, it stays as a flat piece and disappears inside of what appears to be a slot all the way across the front of the wing? The right one does not attach to the "rib" like the left one. Could be the picture quality, but it certainly appears that way... if it was a pressure sensors the left one would be a tube, yet you can see the silhouette of the wires inside. IMHO

[Owen.C93]

What else could it be? They run the across the rear wing and top of the diffuser during testing.

[Jef Patat]

@ speedsense
I don't see what you see

Goes from flat wiring (outside end plate) to round twisted pair under the wing.

Wiring won't go from one type to another, that's just not done. Unless you mean there are several cables under the tape, but then it doesn't matter if they're twisted.

What is interesting is the right one, it stays as a flat piece and disappears inside of what appears to be a slot all the way across the front of the wing? The right one does not attach to the "rib" like the left one. Could be the picture quality, but it certainly appears that way...

Where do you see that?

if it was a pressure sensors the left one would be a tube, yet you can see the silhouette of the wires inside. IMHO

Why should a pressure sensor have tubes? It can be just a very small piezo.

[fiohaa]

this is an extract from mark hughes article off sky:

'So why was this much less of a problem for him in the earlier races? Jenson and McLaren would probably love to know the answer to that too. But there is at least one key rival convinced it has something to do with an FIA clarification made during the Chinese Grand Prix weekend regarding the McLaren's splitter aft of the nose.

It's believed McLaren was taking advantage of the production tolerance allowed for the floor - which has to be flat but which is allowed a few millimetres tolerance - by considering the splitter as part of the floor. The clarification put a stop to this. McLaren insists this had no serious impact upon the car's aerodynamic performance, but others are less sure. Could it have allowed just enough rake on the car for even Jenson to get the front tyres up to temperature? It's only a theory. But at the time of writing, theories were all even Button and the team had.'

can someone please explain this technically...with some pictures or something. Im sure its been written about here before, but probably not in the context of Button troubles.
thanks

[speedsense]

@ speedsense
I don't see what you see

the twisted pair is the bright line under the wing

This side doesn't have the twisted pair harness, and appears to go into the front of wing.

Goes from flat wiring (outside end plate) to round twisted pair under the wing.

Wiring won't go from one type to another, that's just not done. Unless you mean there are several cables under the tape, but then it doesn't matter if they're twisted.

I have done this very thing a few times when the required route was across body work or wings, it's quite simple really, remove a chunk of insulation, spread the wires out side by side, re-enclose with some medium to hold the wiring, tape to the surface. It's used more often than you may think. Many instances on race cars require custom wiring, especially on the outside of a car. BTW, if you do this on carbon fiber, it needs to be insulated from the carbon as it's a conductor.

What is interesting is the right one, it stays as a flat piece and disappears inside of what appears to be a slot all the way across the front of the wing? The right one does not attach to the "rib" like the left one. Could be the picture quality, but it certainly appears that way...

Where do you see that?

The cropped pictures above may need to be zoomed as far as you can go

Why should a pressure sensor have tubes? It can be just a very small piezo.

Having been doing data on race cars for 21 years, I've yet to use a piezo for measurement @ the sensing location. Most pressure sensors on body work and such are sensors that use two tubes running out from the sensor, one to a static pressure (a bottle of water for instance), one to the sensing location. The location could be a pitot or a hole with a small "port" to attach the tube to take the pressure reading.
The wire is connected to the "rib" on the right side and my best guess is a strain gauge reading of some sort. The right one, I have no idea. Like I said, it could be the picture angle and quality but it disappears into the wing....

[scarbs]

this is an extract from mark hughes article off sky:

It's believed McLaren was taking advantage of the production tolerance allowed for the floor - which has to be flat but which is allowed a few millimetres tolerance - by considering the splitter as part of the floor. The clarification put a stop to this. McLaren insists this had no serious impact upon the car's aerodynamic performance, but others are less sure. Could it have allowed just enough rake on the car for even Jenson to get the front tyres up to temperature? It's only a theory. But at the time of writing, theories were all even Button and the team had.'

From what I understand of Marks article is the T-Tray splitter was an issue.

The entire floor of the car is supposed to be flat. However the rules allow a small tolerance, under the guise of a manufacturing tolerance, so the floor may be higher at one point compared to another. This tolerance used to be 5mm and was reduced to 3mm this year. give the teams a chance to exploit a tolerance and they will take it. I presume from Marks comment that the splitter on the McLaren was tilted up by 3mm at the leading edge. Thus the splitter would allow more rake for a slightly lower front ride height, allowing a better front wing position.

As far as the electronic trickery, this assume is some form of system to regain the loss of their fired overrun. Mercedes engines have used the fired overrun to balance the rear of the car when KERS is harvesting since 2009. This gained even more importance in 2011 when EBDs needed off throttle blowing. This year McLaren are still blowing the diffuser area and still are using KERS, so balancing the rear on corner entry is going to be tricky. We all know Button likes a stable rear end to get the confidence to go fast. Presumably the system is trying, but failing to do that.