pyshin

I have JDM Apexi Type V coilovers on my S13 hatch. I had no problem lowering the front, but when I got to the back I lowered as much as possible and left the coil spring as loose as it would go. The stance was great but of course my ride was bumpy as all hell so I then maxed out the spring's preload and the rear of my car now looks like I'm going to go rally off-road. My questions is how do I lower more without affecting ride comfort..? It's a basic question for suspension gurus so any help will be appreciated.