What is the advantage of rear pullrod with aerodynamics?

[N12ck]

I was just pondering a thought, what is the major advantage of pullrod aside from lower C.o.G, I would have thought you want less disturbed air above the floor, and by moving from pushrod to pullrod you lower the suspension rod towards the floor, when these get lowered does it not affect the aero performance of the floor adversely?

would there be any advantage of moving back to pushrod in the future?

Nick

[Nando]

I thought the reason they ran pull rod in the back was to clean up the area for better airflow?

less parts and more stream lined?

[Lycoming]

http://scarbsf1.com/blog1/2010/10/10/re ... odynamics/

Pushrod may be lighter as it reduces the compressive load on the upper wishbone, at the expense of loading the link in compression rather then tension.

Either way, the differences in terms of CoG is small (less weight ultimately translates to a CoG gain). It's done almost solely for aero. If the situation was such that they felt pushrod would give them more aero gain, they will move back.

[N12ck]

Thanks, I would think it would help the beamwing, but by lowering the pickup points would that not adversely affect the floor?

[tomspotley]

I believe it's not to do with the airflow on top of the floor (the "undercut" flow), but the flow along the rear bodywork and around the upper wishbones which covers the gearbox. Previously the pushrods attached to the rockers above the upper wishbone and all the suspension components had to be housed on top of the gearbox. With these components now housed on the bottom of the gearbox, it allows a much cleaner, tighter packaging in the area above and around the upper wishbones (with no nasty pushrods poking out).

I'm not sure what exactly the purpose is, but my theory is that it's supposed to ensure cleaner airflow above or below the upper wishbones to the beam wing.

Edit: Also I don't think it really affects the flow on top of the floor, as they try to "hide" the pullrods behind the other suspension components which are already there.