Does 1/4" -3/8" ride height make big difference?

[Master Apex]

I just intalled KW CS and have the option to adjust the nominal ride height before corner balance.

I like the idea of lowest possible ride height but the front tires (245/40/18) rub on the inner fender liner during hard cornering.

Current setup is about 1/4" - 3/8" lower than stock, it feels good and still rub a little at some corners.

So I plan to raise it to stock ride height, wondering if anyone knows whether 1/4" -3/8" ride height makes big difference in cornering force for Z4M. I plan to experiment on the next track day but it will be Sep'10 so hopefully someone have first hand experience to share.

Thanks