solid torsion bar bushings... the best rear anti roll upgrade
So as another one of my parts is about to be complete and ready to sell, I figured I would drum up some support for it as well. Just as the title says, I will be producing solid bushings for the rear torsion bar. They will be made out of 6061 T-6 aluminum. They are fairly easy to install with just a little bit of work.
On to why I believe it is the ultimate anti roll upgrade.
As all of you know, the yaris comes with a torsion bar rear suspension, fairly common in economy fwd vehicles. While they aren't as good as a McPherson strut or double wishbone rear suspension, they have their benefits in that they are very easy to setup, with little ability to adjust things like camber, and toe. Manufacturers like them because they are inexpensive to design in comparison to other suspension setups, as well as having less components to make. Many of you feel that a rear sway bar is the way to go, and for ultimate anti roll, I would say that it is. However, the design of a torsion bar suspension is so that the torsion bar itself acts as an anti roll device. When cornering, your outside wheel loads as weight transfers, causing the outside suspension to compress, in doing so the leverage arm of the torsion bar (where is bolts to the car) and the wheel act to try to twist the torsion bar. In doing this twisting, it forces the steel tube of the torsion bar to exert an exact twisting force on the other wheel in the opposite direction loading the inner wheel, which as some of us might know, is the exact thing that a sway bar does. So effectively adding a rear sway bar is just stiffening the torsion bar. On to where I see the problem, when cornering hard at high speed (G), even though our vehicles are light they produce a large amount of resulting forces, and since those forces are in a twisting manner, fastened to the chassis with a rubber bushing, that bushing is just getting deformed, completely negating the benefit of the torsion bar and or the rear sway bar. With a secure anchor around an aluminum bushing that won't flex, the forces will be transferred through the torsion bar, as they are intended. Now I know what you are thinking, why would toyota do such a thing. As we all know, road cars are made to be quite comfortable riding machines, not necessarily geared to performance. The only downside to this upgrade is the possibility of slight road noise entering the cabin area. If I forgot anything please let me know and I will be happy to fill you in on a little more info, I tried to keep all the math out of it so I didn't lose everybody.
Introductory pricing should be around $125 and that will probably stay the price until after the new year, so tell your girlfriends or boyfriends or husbands or wives you want them for christmas.
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