Vodafone McLaren MP4-27 Mercedes

[Chalke]

I think the slot to the top is there merely because the regs say it must be visible from above. I don't think the slot is there for aero purposes per se (although it might have an aero benefit too), but more to comply with the letter of the rules.

That's absolutely how I read it.


edited to remove shonky maths!

[AdamCarpenter]

I think the slot to the top is there merely because the regs say it must be visible from above. I don't think the slot is there for aero purposes per se (although it might have an aero benefit too), but more to comply with the letter of the rules.

That's absolutely how I read it.


edited to remove shonky maths!

I think you're right. The more I read the regs I realise that the slots are bigger than the allowed aperture size, so Macca can't be gambling on my theory. My guess is that the slots are designed to introduce flow from over the sidepods into the exhaust stream, hoping to divert it downwards in an attempt to seal the diffuser (which i've read is required to successfully run a lot of rake on the car)

[Chalke]

Okay, try some maths...

If we estimate the length of the slot at 200mm and the exhaust pipe diameter at 75mm, we can say that the 'no bodywork' cone at the exit of the slot would need to be just under 100mm at it's widest point...

Which I can see fitting in with McLaren's design, no?

[Just_a_fan]

Remembering Whitmarsh's comments about improving one lap performance for qualifying, one wonders if the exhausts are actually about getting the tyres warm. Although how one would then race with that happening is another matter - unless there is a special throttle map planned...

[ringo]

Random thought about why this might be even better...

If you can generate net thrust, then you're increasing mass flow out the cooling exit, which means you must be increasing mass flow into the radiator, which means that you're getting more cool air into the radiators, which means you're cooling the engine better, which means you can have smaller radiators. Not only might it give you a little bit of thrust, but also decrease the amount of drag due to a reduction in radiator size.

That's not possible. This is a constant. I've seen it being mentioned a couple times, but gotta step in, as it's not correct.
You probably meant to say increase the volume flow rate.

[elliotts21]

I'm a huge Mclaren fan, think they have by far the most attractive car of the year, but as I see it the current exhaust is not legal, here's why:

The last part of the regulations posted earlier clearly state:
"Furthermore, there must be a view from above, the side, or any intermediate angle
perpendicular to the car centre line, from which the truncated cone is not obscured by any bodywork lying more than 50mm forward of the rear wheel centre line."

I read this as meaning after the aperatures, etc. have been defined the requirements of this 'Furthermore' statement must STILL be met.

Look at the car from the side. Can you see the exhaust outlet or ANY of the truncated cone extending from it?

Nope, me either!

Illegal.

I'm still optimistic that they are running this exhaust to test some ideas without revealing their hand either later in the test or closer to the first race.

[NoDivergence]

The truncated cone is not obscured from the side. Perfectly legal

[elliotts21]

Not sure I understand your response. The cone must be visible from the side of the car. The cone originates at the exhaust outlet. If the exhaust outlet is not visible from the side of the car, than by definition neither is the entire cone. To be clear, my reading of the rules is that the view of the cone cannot be obscured, not just the cone itself being blocked by bodywork.

[kris]

Not sure I understand your response. The cone must be visible from the side of the car. The cone originates at the exhaust outlet. If the exhaust outlet is not visible from the side of the car, than by definition neither is the entire cone. To be clear, my reading of the rules is that the view of the cone cannot be obscured, not just the cone itself being blocked by bodywork.

If consider this "or any intermediate angle perpendicular to the car centre line" then wouldn't it be legal. I think the launch version looked more on the legal side than the current one (which seems to be border line).

[Pup]

Not sure I understand your response. The cone must be visible from the side of the car. The cone originates at the exhaust outlet. If the exhaust outlet is not visible from the side of the car, than by definition neither is the entire cone. To be clear, my reading of the rules is that the view of the cone cannot be obscured, not just the cone itself being blocked by bodywork.

The cone does not have to be visible from the side. It can be, and satisfy the rule, but it does not have to be. The regulation states:

"...there must be a view from above, the side, or any intermediate angle..."

I think you are reading 'and' where the regulation states 'or'. You only need one view, 'a view', from either the top, side, or anywhere in between, that is clear. McLaren chose the top view, which is why the slot is clear from above.

[kalinka]

Button on MP4-27 :

"I’m very happy in the car. I’m in a good position. I’m really low, which I always like, trying to get as low as possible, with the way that the car is.
I’m much lower than last year. I can just about see out, which I love. I love that position, well inside the car. I feel I’m part of it. "

Interesting, I can't remember of anyone mentioned lower driver position here, neither I could notice it. So it means that they were working really hard on low CoG ? They stated that the low nose contributed to this, but they didn't mention the driver's position, which must have a lot of influence on CoG.

Later he added >

"The front wheels are on the front, the rear wheels are on the back, it feels like it’s going in the right direction, and when you turn right, it goes right. Sometimes that hasn’t been the case."

That proves how far back they were in pre-season in previous years. They really need a good start in 2012.

source : http://www.totalf1.com/full_story/view/ ... art_of_it/

[adrianjordan]

Button on MP4-27 :

"The front wheels are on the front, the rear wheels are on the back, it feels like it’s going in the right direction, and when you turn right, it goes right. Sometimes that hasn’t been the case."

That proves how far back they were in pre-season in previous years. They really need a good start in 2012.

Don't forget some of the Honda cars JB has driven!!

[raymondu999]

I think the gist of the comment is that the car is predictable; and you can kind of feel the grip easily in the car; both of which are Button-demanded traits of a car

[beelsebob]

Random thought about why this might be even better...

If you can generate net thrust, then you're increasing mass flow out the cooling exit, which means you must be increasing mass flow into the radiator, which means that you're getting more cool air into the radiators, which means you're cooling the engine better, which means you can have smaller radiators. Not only might it give you a little bit of thrust, but also decrease the amount of drag due to a reduction in radiator size.

That's not possible. This is a constant. I've seen it being mentioned a couple times, but gotta step in, as it's not correct.
You probably meant to say increase the volume flow rate.

No it's not constant at all – increased thrust means more mass is going backwards to generate that thrust. If thrust wasn't involved I would agree.

[timbo]

No it's not constant at all – increased thrust means more mass is going backwards to generate that thrust. If thrust wasn't involved I would agree.

Mass conservation anyone?
You can't have more mass, you can have more impulse.