All righty... now we're at the point of insanity. Basicially, since we're building a new ITA chassis anyway, I'm tossing around the idea of replacing the G-Force panhard bar with a home fabricated mumford link. Nothing *wrong* with the panhard, except I know that it's less than ideal whereas the mumford is AFAICT as close to optimal for a live axle rear. At least Mallock thought so.

Anyone know offhand how you calculate roll center for the mumford? I *can* figure it out myself, but it would be nice to have some reference. The other thing is, well, has anyone actually heard of anything like this being done in any 7?

This is probably going to be one of those threads where noone has any idea what I'm talking about.

 

Sorry, But I have no Idea what you are talking about.

 

i too have no clue what you are talking about, but posting this in the racing section might help...

 

Yeah, well, that's the next step. Might as well go and do that now.

http://not2fast.wryday.com/chassis/mumford.gif shows what I'm talking about pretty damned well.

 

Looks interesting, but I've never seen one before. Hopefully this thread will produce something worth keeping.

 

THAT'S NEAT. Never seen one used before. New territory with a 1st gen!

That's a lot of fabrication though. Here's some pics of actual implementations.

http://not2fast.wryday.com/chassis/mumford.shtml

Have you found out if that Mumford is legal in ITA?

I've seen some sharp looking Watts links in EP and GT2/3. With center pivot point right behind pumpkin, or right BELOW pumpkin!

 

Well, near as I can figure, it's at least as legal as the panhard bar and tri-link are.

And yeah, it is a bit of fabrication... we're doing our own cage too though, so not really afraid of that. It'd also be a bit heavier, but the weight would be (very) low to the ground and in the back... and I'm planning on having to run a *lot* of ballast anyway.

I haven't noticed anyone using anything like it around here (well, except for the guy with a Mallock) but then again, I hadn't previously been looking exactly for it. Even a chassis mounted Watts link would be vastly superior to the stock setup, but as long as we're making stuff, why not go for what should be the best?

 

Keep us up to date on the progress!

 

IIRC you find the roll center the same way you find the instant center of a 4 link - you just extend the two main links and where they meet is the roll center.

Mumfords kick *** just for the "holy crap what is that mess holding the rear axle in" factor.

 

Was the Mumford Link ever implemented Kenku?

 

Was the Mumford Link ever implemented Kenku?

 

This makes my brain hurt! Sorry just showing some interest.

 

I saw some pics of a Mumford setup on a first gen a while back on Mazspeed.Its pretty trick and apparantly works great if you get it all setup right.I wonder,how much weight it adds though,looking like you crammed a treless bridge under there.

 

While the mumford link sure looks cool as hell you would have a whole bunch of fabricating to handle the loads that will be put through link. Yes it does some things that a regular watts link can't do (easy roll center height adjustment) but the weight of all added stuff to hold it kind of defeats "add more lightness". A panhard rod does just fine on the first gen. When modeling rear lateral locating there isn't much change in having the roll center anywhere from 4-6 inches off the ground. Going to low hurts because it may slope the roll axis down toward the rear. It also will make the car require more swaybar. Picture grabbing a sledgehammer right under the head and twist your hand, pretty easy right? Now slide your hand down the handle away from the head, twist your hand now! Holy crap! right? Your hand is the roll center and the heavy head is your center of gravity.
I'm sure Susko has considered using one if his modeling program showed any sort of advantage. It's a big $$ program, I think Reynard uses the same one, and GM.

 

I still think that if you're really serious about making an FB corner well, eventually you'll have to swap an IRS setup in. Perhaps mumford, or a well sorted panhard will be better than a watts, but you'll still have a live rear axle. You'll still have 50's technology.

I'm using a Ford 8.8" setup at the moment, with the original watts linkage, as soon as I get sick of it I'll get a S5 or S6 setup grafted in. Well, as soon as I save US$10k or whatever it costs