torsion bars ok to use

[red83911]

Originally Posted by rnln

red83911,
What kind of squeaking do you hear. Is it more like metal scraping or is it like "ticking"? I know squeaking is squeaking but I want to make sure.
Thanks.

It really did not sound mettallic, and it was hard to trace when driving, somewhere under the floor.
It first started in warm weather, on country roads & a passenger on board, more in time with the damping action of the suspension rather than hitting road ridges etc directly.
If the temperature was below say 20'c it didn't seem to occur-until recently.
Push down on the suspension when stopped and no squeak.

The bars when removed were actualy well greased, I think the below a-arm bushing will give the reason for the bar rubbing due to the rubber flowing. Mine is quite a low milage car and understand this flowing of the rubber bushing is age related rather than mileage.




Also now just been told OEM bars from Porsche dealer are now on back order.

[911-32]

I have some front bars removed from a ~70k mile 1989. Will be the same diameter as your 83 as only the rears changed for later G50 cars. Send me a PM at richard.bernau "at" rbs.com. I will do you a much better deal than the dealer as they are worth virtually nothing to me.

I am London area but post won't be ridiculous.

Richard

[island911]

Originally Posted by burgermeister

...

Not to be outdone... (Nastran (rocket science - ha!) - 1mm 2nd order tetras, 1E6 N*mm, 19mm bar, 0.5mm smooth depression and 0.5mm sharp scratch)

Island, what software are you using? Looks unfamiliar but cool.

Similar results (encouraging when different software has similar results! Happens less often that one might think...)

"Not to be outdone..." HA! --Well done!

the software; CosmosWorks Professional - http://66.223.111.93/pages/products/documents/CWdatasheet2007.pdf



The pre & post-processers rock. And, the Cosmos solver uses what they call FFE (Fast Finite Element) ...which is essentially math, looking at the matirx for symmetry...which can then be solved much faster. ..which means I don't have to use a lot of symmetry BC's on sliced-up models.

So really, the whole package theme is about speed.

FWIW, I used a courser mesh than you. 2.5_mm element size. Adaptive mesh off. ..so some elements aspect ratios (at the scrape) did go over 3:1 ...and a few up by the splines over 10:1. --see disclaimer below.

[ianc]

Very interesting thread. Good work fellas; a great break from 'what's the best oil to use'!

ianc

[burgermeister]

BTW. for the non-geeks, Island's lovely cutaway stress plot shows why hollow torsion bars work - the blue stuff does nothing

[island911]

Yeah, I'm pretty much giving up on the non-geek crowd who are here (paradoxically) on this Tech board. They would rather talk about whether "Hyper black" is more gray than black . .. or the "correct" color of orange. . .shining this or that. . . .bolt-on whatever crap as long as it looks gud, or is loud... And THEN they (again, paradoxically) make fun of "ricers." pathetic, really.