[maxrpm]

Wilf, what I meant was I think taking a car at high speeds thru a racing course, braking cornering then accelerating would probably need a different suspension setup for optimum control. Probably different spring rates also. But I'm just babbling- I've never thrown my car into a corner at 90mph, so don't really know what it takes...aside from maybe first downing a pint of JD old #7.
I believe your statement about using softer springs than typical is the answer this thread was looking for. Most street cars are set up with higher spring rates that aren't suitable (or necessary) for public roads with all the dips, bumps and road kill we have to drive over. I think in one of my first responses to PCC I recommended softer springs. The softer the springs, the less chance of the bumps in the road upsetting the car at high speed. Now take that same soft front spring to a track, drive deep into a turn, brake hard and the car will probably nose over from all the weight transfer onto the front springs, causing a light condition in the rear- so when you accelerate out of the turn- the back end wants to come around. The heavy front springs don't let that happen.
About that windshield, my speedo quits at 160 & so did my shield-it cracked right down the center. I installed another but kept thinking about it. So I ordered a polycarbonate from Cobra Restorers and now the nightmares of eating my shield at speed have stopped. over-n-out.
Ed