thats your problem you see... koni springs are naff, and the quality of them is worse than standard springs...

koni admit that they're springs are crap and advise you to buy their shocks and then get a different brand of spring

get some eibach or H&R springs on those koni shocks

i cant see how it's gonna be that low, didnt ever have a single prob in my mate's ca with 17's and 60mm drop, tbh it coulda gone down about another 40mm without many probs, IMO you must have the wrong tyre size or offset