RTFC

I see talk on another post about rear bracing for performance. Here is a setup I have designed about a year ago that I had planned to make for my Camaro if eventually get around to ever getting coilovers on it.

There's a swaybar option that goes with it also, but this is enough of a start(the stock bar could still be used). This shows a better setup than the panhard rod and would really strengthen and box the rear section of the chassis much much stronger than the panhard brace. It also gives rear roll center provisions. The axle remains constant centered under the car always no matter what the suspension travel is.

The only cutting and welding involves the axle housing. The design intentions are to remove the existing spring mounts and bulky panhard mount brackets from the axle tube and then position and weld the two new locator mounts to the housing tube.

RTFC

This is what it would look like assembled

NEEDforSPEED

mum ford, id be sacred to try something with that ford in the name

aaron7

iTrader: (7)

Looks neat, but I can't see it! Well, I can see the pic, but I have no idea what you are talking about!

RTFC

Here's a few links showing some views of Mumfords

http://susprog.com/images/Susp23.jpg

http://www.bevenyoung.com.au/mumford.html

http://aolsearch.aol.com/aol/image?q...nType=imageTab

ME Leigh

I wonder how that would work with my new decoupling torque arm with telescoping link. I just fabbed it up last week. The torque arm is 18" long.

83 Crossfire TA

iTrader: (2)

I don’t get it:
- what does the little bolt on brace on the left hand side actually brace?
- as far as I can tell the IC of this linkage looks to be where the line formed by the 2 side pivots cross. Lower then stock, especially on a lowered f-body where the front roll center drops faster then the rear is nice, but as low as it looks like it could end up in those drawings is probably too much. Either way you’ll need REALY stiff springs/sway bars to compensate for that low roll center (nice for a race car that always rides on smooth surfaces, but could quickly turn into a PITA on a street car).
- what you gain compared to a phr- mostly no side load. In practice the side to side motion with a sway bar the length used on the f-bodies doesn’t move side to side significantly with suspension travel. Shorter bars that do exhibit more side load, but it would be fairly difficult to build this in an f-body. FWIW, this linkage looks like it will have a bigger IC change with bump then the stock PHR, especially with lower IC settings. Changing IC’s are not a good thing in the same way as bump steer is not a good thing.
- what you gain over a watts linkage… no idea, this appears to be heavier, take up more space, more complicated and will have a bigger IC change with bump. With a watts linkage the IC ends up wherever you mount the pivot, and you can put it on the body or on the axle, depending on what you want it to move with. You’ll get 2x the IC change with bump that you would get with a PHR, but it would be more consistent and still lower then it would be with the mumford. As long as you keep the pivot size reasonable there isn’t much of a reason why you couldn’t get the watts linkage IC as low as you could possibly want it on an f-body.
- where do you run your exhaust with this thing?
- that brace + pivots as you’ve got them designed are going to weigh a ton… well, at least the extra weight will help some with the ride you’ll need with the stiffer springs/bars

JPrevost

I like the Watt's rear linkage personally.
http://www.musclecarnews.com/Article...yId=2004-01-03
But the Mumford is nice too. Can't see any reason why you'd want your roll center below ground with a live rear axle but I guess some people do. I should have asked Claude Rouelle during his last seminar. Oh well, next time. If you ever get the chance to talk to him DO IT or at least listen in on his conversations. His books are pretty deep but well worth the reading material for any engineer interested in cars.
BTW, any 3rd gens running a watts or mumford rear? I thought I had a picture of a 3rd gen with a vertical watts but I can't find it.

RTFC

The above is simply a sketch.
In that scketch, yes, it is showing technically a roll center lower than stock.

The scketch is not to scale, it is a design example and the mount points would be taylored to my individual ride heght and desired roll center adjustment range.

I would never, nor should anyone else ever run a rear roll center below ground, that link simply states that this design COULD allow it if the adjustment provisions were spec'ed for it.
Now, this setup would be the same if not lighter unsprung weight than the stock panhard rod setup with axle bracket.

That brace on the left is called "cheap insurance" to eliminate any potential of twist movement on the dirives side that would compromise the torque of the mount bolts in the stock frame location. That lateral beam is now a crucial support structure for the suspension location, whereas before it simply braced the bracket on the opposite side of the car- now it carries the load itself. That brace is sprung weight.

Location of the axle mounts is not to scale or angle of attack in the scketch. What this Mumford setup has over a panhard is predictable lateral locating on both left and right corners. A panhard can unload one way and load the next if not located properly during suspension travel.

A watts is great, but try and hook the center pivot point to a 10-blot GM rear without adding a very heavy support bracket. They are more suited for ford rears that access the gears from the front. You can NOT mount a Watts successfully geometry wise through travel by locating the pivot on a cross beam and the links on the axle- a Mumford you can. The lower link of a watts would creat such a hazzard clearance wise to the road because it would hang far down in the adjustment range to lower the roll center from stock.

Edit: forgot to add- the exhaust has the same exact clearence as the stock panhard rod brace position. No change needed for exhaust routing.

The IC can and will move outward in a corner making less leverage on roll with this basic design.

racerc

so basicly its a modified watts link??

JoBy

Panhard & Watts:



On this picture the pivot point of the watts link is on the chassis, usually it is on the axle.