The relative benefits of a pull rod suspension

[xpensive]

...
They will see compression forces when cornering in both push and pullrod set-ups.

That would be obvious, but what marcush mentioned is the shock/bump load, which is what you fear with Euler.

[dren]

...
They will see compression forces when cornering in both push and pullrod set-ups.

That would be obvious, but what marcush mentioned is the shock/bump load, which is what you fear with Euler.

Is that the pullrod relative to the chassis or suspension arms?

[ringo]

Euler's name was called, where is the Euler cordinate math to go with the Euler?

[xpensive]

...
They will see compression forces when cornering in both push and pullrod set-ups.

That would be obvious, but what marcush mentioned is the shock/bump load, which is what you fear with Euler.

Is that the pullrod relative to the chassis or suspension arms?

Don't get the question there really, but the stretching force in the pullrod, must of course be equalled by compression forces in the arms. In a pushrod application it's the other way around, which is just one of the reasons I find it preferable.

"Springs should be compressed, rods should be stretched", is a mantra my university professor kept repeating.

But I don't know, this is perhaps not a problem worth considering here?

[Mr.G]

At the risk of pouring a little oil on the fire ...

There is absolutely no reason to think they're changing back to push-rod. Why would they? The current pull rod setup works well. The front suspension is not Ferrari's problem.

I think tahn next season we will see more pull rods, not only on Ferrari.

[myurr]

I thing next season we will see more pull rod, not only on Ferrari.

It's certainly a possibility, and it's very interesting to see the Ferrari continue to do well despite this perceived handicap. Shows that it really isn't getting in the way like some members insist just because it looks a bit funny to them.

[shelly]

@x: aren't ferrari eng with pullrod exactly following your teacher's mantra by stretching rods? It is the othere teams who are compressing rods.

[heho07]

Scarbs said:Teams could find a benefit in front pull rod, but the 2014 low nose regulations are unlikely to pullrod, so any gain would be for just one year.

But i though that in 2014 pullrod will work better due to lower nose that increase pullrod degree relative to horizontal line.
Do anyone know Why did scarbs say tha ?
Thanks.

[flmkane]

The way I see it the only reason the pushrod got replaced by the pullrod at the rear, was because of the tiny diffuser mandated by the 2009 rule changes.

If we still had pre-2009 rules I think teams would have stuck to push-rod rear suspension.

As for the Ferrari front pullrod, I dont understand it. May I request a link to any good article about it ?

[PlatinumZealot]

Read this thread from the start.. its elementary though.
In summary:
Similar motion ratios to push rod can be achieved.
Pull rod gives lower CoG
More difficult to access (to change settings)
A cleaner air flow path is achieved near the midline of the car.. and a better air flow near the lower end of the brake ducts.
Pull rods are lighter (in theory at least) and take up less volume.
Pull rods can work with either a high nose or low nose as evidenced by F2012 ferrari.

Pull rods are a no-brainer.

[Lycoming]

Pull rod gives lower CoG
More difficult to access (to change settings)
A cleaner air flow path is achieved near the midline of the car.. and a better air flow near the lower end of the brake ducts.
Pull rods are lighter (in theory at least) and take up less volume.

I should note that none of these features are a given; that is, none of them are inherent to the design. You can design a pullrod system where, as compared with an equivalent pushrod system, none of these points are true.

Lower CoG depends on how you package all the stuff inboard. If you had vertically oriented dampers before and after, the change would be quite small, if any. similar deal with access; you can create a pullrod system where the components are just as easily accessed.

Pullrods are lighter/thinner than a pushrod that must withstand the same bump load... but it loads your upper wishbone in a less satisfactory way compared to pushrod. These gains are lost, in part or in whole, when the upper wishbone is modified to take the larger compression load. Just have a look at how fat ferrari's upper wishbone is.

[ringo]

Well after 2 years it's been one of the most interestign threads. Pull rod was truly a "no brainer", though in fairness that debate was up in the air until the 2011 season was concluded.
Took one year to conclude on the pull rod rear, and another on the pull rod front, which little evidence since it was only ferrari using it.
Mclaren have chose to use it, so i think we can look into the decision making behind the front pullrod.

[PlatinumZealot]

First of the front pull rod converts.


http://www.f1fanatic.co.uk/2013/01/31/m ... -b-2013-1/

[heho07]

Please answer my question.
Why Scarbs think that "Teams could find a benefit in front pull rod, but the 2014 low nose regulations are unlikely to pullrod, so any gain would be for just one year."

[Richard]

The nose after 2014 will be a lot lower, so Scarbs is thinking that push rod is the only option. If that is true then any teams developing a pull rod set up this year will have to throw all that development effort in the bin at the end of this season.