Join Date: Nov 2001
Location: state of confusion
If it's flat ride pitch behavior that you're talking about maintaining, you'd probably need to increase the rear wheel rate a little bit more than proportional to the front wheel rate. IOW, a front wheel ride rate increase of 33% might need a rear wheel ride rate increase of, say 40%. This is more of a street-driving consideration.
If it's a matter of roll stiffness and lateral load transfer that you want to hold constant, you should also consider the effect of the stabilizer bar(s) and roll center heights. In this case due to having a much stiffer front bar a 33% increase in front wheel ride rate should only need a smaller increase in rear wheel ride rate in order to maintain that balance.
Mine: '08 GT, 5MT, black/light graphite, un-Fstock (DD, occasional track day)
Wife's: '10 Legacy 2.5GT (DD, six-speed manual)
Spare:'01 20AE Maxima, 5MT (also my bad weather alternate)
Various Loose Parts: '79 Malibu