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What is peaky downforce ?


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#1 pbukovca

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Posted 12 July 2013 - 21:08

Hello guys,

I'm aware that a peaky downforce map has downforce peaks optimized over a very narrow ride height range. The peak is probably taller but also not as broad as a less peaky curve ?

Does peaky downforce always mean less progressive downforce (I mean does the car balance change much quicker with a peaky aero map giving the driver problems with the car ) ?

My understanding is that a broader ride height aero map give you less peak downforce but more downforce in the other areas of the map where the troughs would be and also that in addition to this

it is more progressive making the car easier to drive as it moves on around on it tires and suspension ?

Many thanks in advance for taking time to read this.

Am I missing anything here ?

PS - Does anybody know what parts of the car can make peaky or less peaky ?



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#2 JimboJones

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Posted 13 July 2013 - 10:16

Hello guys,

I'm aware that a peaky downforce map has downforce peaks optimized over a very narrow ride height range. The peak is probably taller but also not as broad as a less peaky curve ?

Does peaky downforce always mean less progressive downforce (I mean does the car balance change much quicker with a peaky aero map giving the driver problems with the car ) ?

My understanding is that a broader ride height aero map give you less peak downforce but more downforce in the other areas of the map where the troughs would be and also that in addition to this

it is more progressive making the car easier to drive as it moves on around on it tires and suspension ?

Many thanks in advance for taking time to read this.

Am I missing anything here ?

PS - Does anybody know what parts of the car can make peaky or less peaky ?



Yes, yes, and yes, you've pretty much covered it!
although the driver will only struggle with balance changes etc if you fail to keep it in that narrow operating window. A team could develop a very 'peaky' map based on a narrower operating window - so ride heights not changing much. But you'd have to run the car very stiff, or have sophisticated ride height systems to achieve it - it's obvious which has to come first...
The teams will always be aiming for the holy grail though - the effect of active suspension. So fixed ride heights (in cornering), and insane aero performance at those ride heights alone.





#3 Ross Stonefeld

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Posted 13 July 2013 - 16:02

A comment that Gary Anderson once made that stuck with me, is that the driver will tend to be around the lower averages rather than the single absolute peak.

Which is probably a good approach to take to all racecar design and engineering.

#4 Greg Locock

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Posted 13 July 2013 - 23:02



PS - Does anybody know what parts of the car can make peaky or less peaky ?


In my simple aero model the undertray has the best L/D, rear wing next, front wing worst.

In terms of sensitivity to ride height rear wing is least, undertray worst.

As to what details of the undertray can be modified to reduce peakiness,no idea, but the concept of trading peak performance for robustness is very common in general.


#5 Stefan_VTi

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Posted 14 July 2013 - 08:44

Wasn't it common, some years ago, to raise certain sections of the front wing?
I believe the idea was that height variations made a bigger impact with the wing closer to the ground (which makes sense).

So might bringing the leading edge of the undertray rearward, towards the center of rotation of the car (thus reducing the height fluctuation under car movement), be one of the things that can improve stability?

#6 MatsNorway

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Posted 14 July 2013 - 09:43

As to what details of the undertray can be modified to reduce peakiness,no idea, but the concept of trading peak performance for robustness is very common in general.


Try a steeper angle on the diffuser. It should work on a narrower area of ride heights? no wait. you want the opposite. Less angle then. (no clue just guessing)

Edited by MatsNorway, 14 July 2013 - 09:43.


#7 gruntguru

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Posted 14 July 2013 - 22:53

or perhaps some sliding skirts. :)

#8 Kelpiecross

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Posted 15 July 2013 - 03:52

"Peakiness" - a small, somewhat ugly breed of toy dog originating in China. Not much use for rounding up sheep.

#9 Greg Locock

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Posted 15 July 2013 - 05:31

"Peakiness" - a small, somewhat ugly breed of toy dog originating in China. Not much use for rounding up sheep.

The Chinese only ever deal with integer numbers of sheep, so they don't need rounding up.

#10 Tony Matthews

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Posted 15 July 2013 - 10:24

^ :up:

#11 munks

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Posted 15 July 2013 - 15:58

Well I see this thread has been won.

#12 desmo

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Posted 16 July 2013 - 00:36

The Chinese only ever deal with integer numbers of sheep, so they don't need rounding up.


:lol:


#13 RDV

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Posted 16 July 2013 - 10:57

....that's wooly logic for you.... :rotfl:

#14 Magoo

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Posted 16 July 2013 - 15:15

Well I see this thread has been won.


Seldom has victory been so clear.

#15 gruntguru

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Posted 16 July 2013 - 23:09

I love sheep - but I couldn't eat a whole one.