Total Lateral Load Transfer Distribution

[stab6902]

All indications point to the need for more rear stiffness or less front stiffness. Since the front is decently soft (1.5Hz undamped) I have opted to stiffen the rear (currently 1.2-1.4Hz undamped).

Are those measured ride frequencies, or calculated? When I actually measured my ride frequencies, I was surprised to find they were quite a bit higher than calculated, especially in the rear. My car (1968 Firebird, 3410 lb, 58% front) has a rear ride frequency of 1.75 Hz with stock 5 leaf rear springs, which have a published rate of 110 lb/in.

To measure the ride frequencies, I took the shocks off one end of the car, put the other end on full stiff (to minimize coupling effects), and bounced it. It'll be kind of like pushing a swing - it's fairly easy to feel the natural frequency. The quick and dirty way is to count bounces in like a 30 sec timespan, but I got fancy and used the accelerometer on my phone and then analyzed the data in Matlab. I think it's worth measuring (if you haven't already) to give you a baseline.