Rudy14 wrote:
Andrew, Good to hear your LCAs were thicker walled steel. Since they are painted grey I will look more closely before autocrossing again. What general added strentgh would you say this provides ?
No hard bottoming out of the suspension has taken place, as that seems when a stress crack could develop.
Dave
Aka "Rudy 14 "
Hey Dave. I don't remember the exact percentage but it was significant (I want to say 25-30% off the top of my head; 0.083" is 132% of 0.063" so close enough). Braking is really what kills the arms since the forward leg goes into tension and weight transfers from the rear wheels onto the front which further increases the tensile load in the forward leg of each lower arm.
Getting the springs and bars as close to the ball joint as possible also helps to minimize the bending load on the tubes. Graham's illustration is exactly what happens. The "book" seems to encourage this design and it was probably okay for the 1,200-1,300 lbs cars with <100 hp it was intended for.
Nice looking avatar BTW...I feel like I've seen that car somewhere....