ahh, don't be a dick... The question provoked a thread that I (n00b), found interesting.

 

Can anyone direct me to any sort of a website that gets into the nitty gritty aobut these KM hubs, or is it just in the book?

 

I haven't found one in my internet travels, but the basic gist is that depending on how you throw the weight of the car around, the rear wheels track differently under different conditions...

It's also known as a "Toe Control Hub", which is perhaps the best name to give it. Camber is flexed in most suspension systems through shock travel, but in our Rex's, the whole trailing arm assembly acts as a weight distribution pivot that allows the toe to be 'flexed' in tiny amounts (1-5 degrees - practical application has seen this to be close to 2, unless your bushings are worn, like mine, when you'll see 5-12 degrees.)

In effect, it's similar to 'rear steering', except it has to do with the car's attitude than with actual steering wheel position.

As I've discussed with my physics profs (keep in mind this is all just theoretical, I haven't done it yet - but I will), in theory, if you swapped all of your rear bushings to poly, and some short axle extensions or wide rear tires, this effect would be amplified more reliably than with my worn bushings.

The KM hub is one of the reasons our cars slalom so well, as we're tossing the weight back and forth, forcing the maximum travel on the KM system, thus the most 'effect'...

It's also how I can smoooooke people around clover-leaf ramps.

That's the idea.

Does this help?

~Brave Blue Mice

 

It's discussed pretty thoroughly in the Jack Yamaguchi RX-7 book.
If you can get it, it's THE Holy Grail book for all fanatic FC (they also have an FD one) owners.
It has everything and anything you wanted to know about your FC...

There are some SAE papers available, but it's a pain in the *** to track them down.
http://www.sae.org/ if you're stubborn.


-Ted

 

Which book is it? Amazon has the following books:

RX-7: The Mazda RX-7: Mazada's Legendary Sports Car
Rx-7 the New Mazda Rx-7 and Mazda Rotary Engine Sports Cars

I would assume the 1st is FC, the 2nd is FD?

-=Russ=-

 

Actually, the second one you listed is the FC book. The first is the FD.

You can find them on eBay every now and then or by searching Amazon's used book dealer network.

 

So I take it they're a worthwhile read? Amazon has a few... is it a worthwhile "Christmas present to self"?

-=Russ=-

 

Interesting note, The rear suspension on the FC is still copied. My wife's New Beetle's rear looks almost like an exact copy! The salesman was talking about the rear steering asist suspension like it was a new thing.The real benifit, as mentioned before, is space savings. We can shove a whole lot of crap in either vehicle.

 

They're both well worth the read Russ.

Jerry