Best spring rates for Gaz gha’s

[172joe]

I’ve got Gaz gha’s on my 172, on 15x7 et35 wheels with 195/50/15 tyres. I’m lowered a bit but nothing silly. When cornering hard i get a lot of rubbing on the front so thinking stiffer spring rates will help sort this. What do people recommend for track/fast road?
Cheers