View single post by Jensenman
 Posted: 04-03-2007 06:04 pm
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Jensenman

 

Joined: 04-14-2005
Location: Columbia, South Carolina USA
Posts: 156
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A solid axle setup, correctly designed, is as good as an IRS in many applications. A circle track car, since it only turns one direction, is a perfect place for a stick axle.

A lot of the solid rear axle setup secrets lie in the suspension's roll stiffness; the less body roll the better since that minimizes the roll steer of a four link setup. Of course that brings up its own set of problems. I battled that whole thing with my 1979 RX7.  The best set up early RX7's are using a 'tri link' setup which minimizes the roll oversteer. Thing is, by the time you do all that, it's just as easy to build an IRS. I am currently building a rotary powered Opel GT which has a stick axle stock. I have a complete 1st gen RX7 limited slip disc brake axle, my first thought was to narrow and use that. After crawling all over, measuring everything, and plotting suspension mount points for best rear geometry, heck I'm going to build an IRS for it, too.

Where an IRS shines is over uneven surfaces and in its tuneability. Being able to add and remove camber and toe in or out without having to replace the axle housing is a good thing. For instance, the Kumho V700 tires I was using on my RoSpit are discontinued, and when I went to the new ECSTA V710 it was easy to set it up. It took one afternoon, a set of toe plates, a bubble camber gauge, a memory pyrometer and a handful of shims.

Last edited on 04-03-2007 06:10 pm by Jensenman