Standard 13" Speedlines with the standard Michelin tyres are only 10mm lower than the 15" Clio Speedlines with 195 45 tyres at the front and only 5mm lower at the rear, as the front squashes proportionally more with the original 'balloon' tyres.
1/2 Total height of wheel = 7.5 inches = 190mm. Tyre I have to guess at about an extra 90mm.
So half height is 280mm.
so the extra 10mm is 1/28 more leverage on the brake or 3.5%.
does anyone know where I can get the bolts from for this kit?
I can't remember the thread size but, most hardware stores should be able to help you out. Just make sure that they are high tensile 12.9.