RobertE

Looking for some answers to a few questions.. would appreciate any advice from the regulars(Fabrik8?) in this section.

I'm about at the stage where I can start fabbing up some items for my rear suspension on my MG(currently waiting on a ford 8" rear end housing)
For anyone not familiar with the MG design it is a solid rear axle using leaf springs and lever arm shocks.

I've seen a few setups but have a few questions before venturing down this route.

1. The pan-hard rod should be as close to horizontal as possible, correct?
2. Should it be as low possible(within reason)?
3. Would using a rod that extends from one side of the axle(mounted on the body of course) to the center line of the housing be okay? I've also seen it run from one side to the other before, but that seems unnecessary.

Thanks for any help

Fabrik8

I don't really know anything about that car, so I don't know what you have for packaging constraints, etc., but in a general sense a panhard bar should be as horizontal as possible, yes. You also want to make it as long as possible, which will make the arc (that the attachment point moves around) as large as possible. Making it as low as possible doesn't do anything for you unless making it as low as possible also makes it as horizontal as possible. You want it running from one side or the other, as far as you can, which goes back to the concept of making it as long as possible.
It's all about geometry; the shorter the panhard rod is, the more the axle will travel sideways as the axle travels vertically. That's obviously not a good thing. A longer rod makes a larger, gentler arc. All of that basically explains why panhard bars aren't that great.

IF you can (again it goes back to packaging) you might want to look into a Watts link setup instead. It's a big improvement over a panhard rod and it makes the axle have much less sideways movement as it travels vertically. It's still not perfect, but it's a lot better (more vertically linear) than a panhard rod.

If you're dealing with a modern axle, like that Ford 8 inch, you may find that there are convenient mounting points to do something like that. I'm try to bury my head in the sand and stay away from solid axles as much as possible so I don't know the specifics of the Ford 8 inch... I'd say to look at the cars that use that axle and see what they use; copying (or slightly modifying) the stock configuration is probably the easiest thing to do as long as it isn't too compromised.

And yes, I know Mustangs, etc., have used panhard bars. I'll let you interpret the next part of what I would say about that.

RobertE

Thanks! I have been considering a watts-link as it's at preventing lateral movement but I'm still trying to find somewhere I can find the rods/helm joints.. Maybe I should take a local trip to a race shop and see what they're up too.

Buying an IRS with a differential won't last with a v8 swap isn't an option at $3,000+

Here is a rough idea of what I'm working with minus the new upgraded tube shocks.

RandomTask

THIS may help you.

So you're doing a v8 swap? Looking at that pic, if you have any power at all with some grip you're gonna run hard into axle wrap (read wheel hop) Any way to add a third link?

RobertE

Britishv8 is a great site.. lots of helpful folk.

Yes, I'm swapping in a built 5liter rover(3.9 stroked via buick 300 crank) ported heads and other goodies.

I'm probably going to end up making some traction bars or a pinion snubber.

The wind up and ensuing wheel hop with leaf springs and anything over 250hp is atrocious.. you're liable to have your fillings knocked out.

FlimFlam

IRS FTW!!!

Fabrik8

Oh, I see you've read my posts before..

Fabrik8

Maybe consider something like this:

http://www.speedwaymotors.com/Watts-Link,3398.html


There are also the "reverse mounted" Watts link that mount the center pivot on the chassis and the link pivots on the axle, instead of the link pivots on the chassis and the center pivot on the axle. The reverse mounted probably has some mounting advantages and you can do some interesting things with roll coupling (by adjusting the pivot position vertically), BUT there are some subtle differences with how it works. Isn't usually a problem if you have limited suspension travel though.

Fabrik8

I forgot to mention why it's better to have the center pivot attached to the chassis: It prevents the axle from moving sideways when you have vertical axle travel while in roll. So if you hit a bump when in a corner, you can have some sideways axle moving if you have the pivot on the axle and not the chassis.