Vodafone McLaren MP4-27 Mercedes

[amouzouris]

yup...tire marbles....so now the question is...does the car destroy its tire sidewalls??

[ajdavison2]

Said that a few pages back but it got dismissed?

[beelsebob]

i actually said before that i think mclaren is trying to seal the diffuser by deflecting the exhaust plume...BUT on second thought i find it hard seeing how air moving from 180-300 kph could deflect the exhaust plume traveling at 600-700 kph at 90 degrees...also..last year the exhaust was far closer to the floor but we didnt see any kind of floor burning because of the use of heat shielding materials...so why wouldnt mclaren use heat shielding materials again which would both keep what they are doing a secret...so what we are seeing on the floor might actually be parts of the tire ripping apart and being thrown on the floor by the wheel turning... since they are probably blowing the brake duct fins and also blowing the edge of the tire ripping it apart...
i also had a look on the sauber solution which is very different i believe as they are trying to keep the plume attached to the bodywork...not deflect it by the airstream..

It's not the air flowing over the side pod that deflects the exhaust, it's the low pressure generated underneath the exhaust flow by the shape of the channel in the bump. It's also not 90° that they're deflecting it through – more like 20-30°.

[volarchico]

It's not the air flowing over the side pod that deflects the exhaust, it's the low pressure generated underneath the exhaust flow by the shape of the channel in the bump. It's also not 90° that they're deflecting it through – more like 20-30°.

With the minimum initial angle of the exhaust set at 10 deg up, turning the flow 20 deg is only a net of 10 deg down (yes, yes simple math...). I haven't done a scale drawing, but if that is a scorched floor and not just tire rubber, the exhaust is making a much more significant turn than just 30 deg.

[amouzouris]

It's not the air flowing over the side pod that deflects the exhaust, it's the low pressure generated underneath the exhaust flow by the shape of the channel in the bump. It's also not 90° that they're deflecting it through – more like 20-30°.

With the minimum initial angle of the exhaust set at 10 deg up, turning the flow 20 deg is only a net of 10 deg down (yes, yes simple math...). I haven't done a scale drawing, but if that is a scorched floor and not just tire rubber, the exhaust is making a much more significant turn than just 30 deg.

I agree...also wouldn't a low pressure below the bulge decrease the efficiency of the floor?

[beelsebob]

It's not the air flowing over the side pod that deflects the exhaust, it's the low pressure generated underneath the exhaust flow by the shape of the channel in the bump. It's also not 90° that they're deflecting it through – more like 20-30°.

With the minimum initial angle of the exhaust set at 10 deg up, turning the flow 20 deg is only a net of 10 deg down (yes, yes simple math...). I haven't done a scale drawing, but if that is a scorched floor and not just tire rubber, the exhaust is making a much more significant turn than just 30 deg.

The line for the exhaust is pointed up at 10°, the other is down at 20° – it requires at most a 30° turn, which is easily possible with an aerofoil of that length.

[amouzouris]

I actually measured the angles...here have a look:

[beelsebob]

I actually measured the angles...here have a look:

You've measured from the back of the bump – the exhaust pipe is at the front of the bump. Remember, that's a launch car.

[amouzouris]

you might have a point..let me look for a test day photo and ill repeat it!

[beelsebob]

Just a note – the rear wing is about the same length as an aerofoil, and turns the gases flowing over it through a much greater angle than 30°, though admittedly it does need a slot to not stall.

[Shrieker]

Yeah just marbles by the looks of it. I doubt McLaren could really blow the floor and make it worth while.

Right click view image to zoom in.

In all honesty, it looks like tire marbles in that pic. I've been mistaken. But why would someone who could see the car up close (Ted Kravitz) with naked eyes would report that the floor has burn marks ? It strikes me as odd. Maybe he's been mistaken in the same way some guys including me have been mistaken.

yup...tire marbles....so now the question is...does the car destroy its tire sidewalls??

As another fellow member pointed out, could that be because of the exhaust flow coming too close to the tyres for comfort ?

[Owen.C93]

yup...tire marbles....so now the question is...does the car destroy its tire sidewalls??

Well Sauber just introduced a similar concept and this is their rear tyres.



I wouldn't say that's too unordinary for testing and what not, but something to keep an eye on.

[amouzouris]

you were actually right bee..i repeated it for a test day photo and it has to deflect it by 30 degrees...the question now is if it can be deflected by 30 degrees

[kalinka]

Must be tyre marbles you are right. That duct tape holding the tyre-temp sensor wire would be the first victim of overheating, and should detach long before the exhaust could burn the floor.
That temp sensor looks pretty temporary. Is it just for testing, or they'll find a proper place + wiring later ?
I can't remember that we saw anything similar ( tyre marbles at that place ) last year. Is it because of the exhaust, or maybe it's just a property of the new Pirelli compound(s), or something else?

[Rozza]

http://img.skysports.com/12/02/800x600/ ... 716012.jpg