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panhard rod link - de dion
bobster - 26/5/07 at 10:14 AM

Hi guys, I need to modify my de dion axle to allow it to fit my diff, rear tub properly.. Can anyone see any problems with following. I need to locate the lower suspension mounts directly onto the de dion tube and then would like to locate the panhad rod (axle end!!!) onto this lower suspension mount using a 90mm M12 bolt. please see poor graphic. Or does anyone have any better solutions. Thanks very much bobster

mistergrumpy - 26/5/07 at 10:28 AM

I may be seeing it wrong butif your panhard overlaps the axle, when there is weight on the wheels the axle will rise and possibly impact and bend the rod. If I'm seeing it right that is.

bobster - 26/5/07 at 10:46 AM

Yes, sorry not the best graphic. The chassis mount is 7" higher than the de dion axle. so I am hoping that at full travel the rod and axle will not meet.

MikeR - 26/5/07 at 10:49 AM

as long as the pan hard rod is approx level at when the car is sat on its wheels with you in it - it will be fine.

The issues is the foces it will be imparting. For every inch you move it from the centre of the de-dion it starts to act as a lever. If you can cope with that, i think you'll be fine.

britishtrident - 26/5/07 at 04:06 PM

Raising the chassis mounts raises the rear roll centre by approx 1/2 the height the mount is raised.

Raising the rear roll centre alters the roll couple distribution --- in effect the car will be stiffer in roll at he rear which will increase any tendancy to oversteer.

Because the panhard rod isn't level you will also get jacking effects.

We might be able to help more if we knew more details of your project.

[Edited on 26/5/07 by britishtrident]

MikeR - 26/5/07 at 07:13 PM

Ah, but if you raise the mount on the chassis and the de-dion, doesn't the roll centre remain the same?

(i'm asking as i assumed it would, hence my comment, i'm curious if i'm wrong now).

MikeRJ - 26/5/07 at 07:55 PM

quote:
Originally posted by MikeR
Ah, but if you raise the mount on the chassis and the de-dion, doesn't the roll centre remain the same?

(i'm asking as i assumed it would, hence my comment, i'm curious if i'm wrong now).


No, the roll center is effectively at the middle of the panhard rod, thus raising just one end by 'x' distance raises the roll center by x/2. Raising both ends by 'x' raises the roll center by 'x'.

bobster - 26/5/07 at 09:50 PM

Thanbks for your help, great to have so many brains at hand!! the suspesion mounts will now be lower (see graphic) and the panhard rod nount will be be on a slight negative plane. will try and get some photos tomorrow for you guys to dissect.