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Re: Advantages of not using rear corner springs

Posted: 16 Nov 2010, 14:56
by autogyro
Is this not a last ditch effort to achieve a workable set up with a suspension that is far to hard?

Re: Advantages of not using rear corner springs

Posted: 16 Nov 2010, 17:11
by scarbs
I've started to look into this. It seems its not that uncommon, other teams beyond Williams and McLaren adopt this. Its simpler, lighter and provides the same range of adjustment. if you think of the issues packaging long torsion bars, especially at the rear and especially for pull rod, the idea starts to make some sense.

Re: Advantages of not using rear corner springs

Posted: 16 Nov 2010, 17:34
by mep
DaveW wrote:
richard_leeds wrote:It would be interesting to hear more about this approach.

Kh = G1*Kc + G2*Kt (i.e. is a linear combination of the corner & 3rd spring stiffness).

Kr = G3*Kc + G4*Ka (a linear combination of the corner & arb spring stiffness).
What is the G1-4 supposed to be?

Re: Advantages of not using rear corner springs

Posted: 16 Nov 2010, 17:57
by DaveW
mep wrote:What is the G1-4 supposed to be?
Constants that depend on suspension layout. I used them to avoid being drawn into discussions about the definition of motion ratio(s), etc.

Re: Advantages of not using rear corner springs

Posted: 16 Nov 2010, 18:12
by autogyro
scarbs wrote:I've started to look into this. It seems its not that uncommon, other teams beyond Williams and McLaren adopt this. Its simpler, lighter and provides the same range of adjustment. if you think of the issues packaging long torsion bars, especially at the rear and especially for pull rod, the idea starts to make some sense.
I have a feeling (and it is little more), that this has something to do with ride height control and the pull rod systems for next year.

Re: Advantages of not using rear corner springs

Posted: 16 Nov 2010, 18:20
by scarbs
autogyro wrote:
scarbs wrote:I've started to look into this. It seems its not that uncommon, other teams beyond Williams and McLaren adopt this. Its simpler, lighter and provides the same range of adjustment. if you think of the issues packaging long torsion bars, especially at the rear and especially for pull rod, the idea starts to make some sense.
I have a feeling (and it is little more), that this has something to do with ride height control and the pull rod systems for next year.
No, I am told this has been done for several years, predating no-refueling and pullrods re-introduction

Re: Advantages of not using rear corner springs

Posted: 16 Nov 2010, 18:45
by autogyro
You say it is not uncommon scarbs and that Williams as well as McLaren and other teams have used the idea.
With the same potential for adjustment and lighter, it posses the question as to why it is not in use on all the cars?

Re: Advantages of not using rear corner springs

Posted: 16 Nov 2010, 19:35
by scarbs
I'm told that some engineers don't warm to the idea, wanting to keep the individual wheel rates under seperate control from pitch. Also it seems the dynamics of soft rear and stiff front roll rates don't suit every driver\car\aero package. Lastly the set up doesn't suit all tracks.

As a hint of how long this has been in use, how long have we seen Hamilton lift\lock his inside front in the air into corners?

Re: Advantages of not using rear corner springs

Posted: 16 Nov 2010, 19:58
by autogyro
I would have thought that hanging an inside front wheel in the air was more a result of hard set corner torsion bars rather than a lack of them.
McLaren has run very hard suspension all this season (whatever the combination).
IMO to maintain a workable range of ride height.

Re: Advantages of not using rear corner springs

Posted: 16 Nov 2010, 20:00
by timbo
scarbs wrote:As a hint of how long this has been in use, how long have we seen Hamilton lift\lock his inside front in the air into corners?
He was really doing it a lot at 2008 but not so much @ 2009-early 2010. He was locking again last few races.
Does that mean they used that setup as early as 2008 then abandoned it, then came back again?
Interestingly I've noticed that the rear does look strangely soft in Brazil.

Re: Advantages of not using rear corner springs

Posted: 16 Nov 2010, 20:01
by timbo
autogyro wrote:I would have thought that hanging an inside front wheel in the air was more a result of hard set corner torsion bars rather than a lack of them.
Hard roll-bar is more likely)

Re: Advantages of not using rear corner springs

Posted: 16 Nov 2010, 20:05
by autogyro
Could be but why more likely?

Re: Advantages of not using rear corner springs

Posted: 16 Nov 2010, 20:31
by Jersey Tom
Lifting wheels is generally more a question of front to rear roll stiffness split (coupled with total load transfer), than absolute roll stiffness. Put so much load transfer to the front that it completely unloads a tire. One of my favorite examples...

Image

(That's if you're not running out of travel, have crazy friction forces, rebound cranked, whatever)

Locking inside tire under the brakes is part driver, part front to rear brake bias, and part alignment and steering settings.

Hamilton certainly has been known to lock inside fronts. Hard to say from us just watching on TV how much is him versus how much is car setup.

Re: Advantages of not using rear corner springs

Posted: 16 Nov 2010, 20:36
by timbo
Jersey Tom wrote:Hamilton certainly has been known to lock inside fronts. Hard to say from us just watching on TV how much is him versus how much is car setup.
Sure, but he didn't lock fronts as often mid season as he did in last race.

Re: Advantages of not using rear corner springs

Posted: 16 Nov 2010, 20:44
by bettonracing
A few ppl alluded to them, but it doesn't seem like anybody explicitly mentioned flexures...

Regards,

Kurt