Producer's original design

As mentioned before the constructive designing of the axle arm bush brings much difference in the taste of ride of the vehicles. I have ever performed some experiment on this effects utilizing NCP10 TOYOTA Yaris tens years ago that had torsion beam axle for the rear suspension design, the hinge arm bushes were filled with butil rubber material to prevent excessive horizontal movement of rear axle actions. As a matter of fact, the ride was worsened much with some sense of push-up unreasonably. Physical performance there had been well considered and set in the best designing by the producer's engineers as a TOYOTA world strategic products.
As for BC7 SUBARU Legacy LSi US model, I took mistakes the cause of the phenomena had been brought only by the suspension and axle designing for US use, to soft with too much compliance like some long used car. This is the reason for my stupid decision at that time to have replaced all the axle constructive bushes into STI(Subaru Technica International) produced especially for WRC competition models. Hardened and strengthened bushes brought some tight and unmovable body shakes, but pushing up has been increased in turn. Hardness, softness, astringency and actual taste of ride had been decided by the producer's factory engineers in the research and developing division after some desperate efforts of experiments with special devices on the way of new model development.
So, my BC7 would be set in original condition as it had been constructed in US, except with 30% stronger dumpers for GC8 WRX Impreza model. As a matter of fact, a breakage of rear left drive shaft inner boot could be good trigger to make a step into a big axle operation this time.
As a conclusion today, No Layman can change the original setting of axle suspension designing in any way, even a small piece of bush if well balanced setting original condition is not to be destroyed by a whim in a moment. The big effort done by the factory engineers previously should be appreciated and admired. Outsiders have no room to cut in to modify the great works except in the manufacturing tolerance of the construction.