Proper ride height for Track

BGTV8

These springs are close to those that the Z34 NISMO RC ships with and are what I would expect as a start for road-racing on slicks - or sticky R-spec's - with large front bar (1.25" or maybe 1.5" hollow) and a small rear bar, but only when the suspension bushes are stiffened right up.

I'm not sure why you'd consider this to be a handful on a road-race circuit unless you reckon it would be too twitchy given the stiffness in the suspension - but our circuits here in Australia are (relatively) smooth - there are a few (like Wakefield Park in NSW and Sandown in VIC) that are bumpy, but the really quick ones like Phillip Island are quite smooth and reward driver committment and a stiff chassis.

Anyway, back to the OP - beware running the car too low, suspension arms need to remain relatively flat and you need enough "bump" to avoid bottoming under braking and bumps which will make the car lock wheel(s) and dart/break-away with little warning

RB

03threefiftyz

I was referring to the set-up on my car would be a handful on a road course, it is just not set-up for high speed turns.

As far as the other poster who wrote lower CG=Good...well, yes in of itself, lower CG is good, but the Z33/Z34 roll centers start to go from meh to really meh once you get below about 1.5" from factory.

Easiest way to figure out how to spring a car is via frequency, which is easy enough to calculate using your corner weights, motion ratio and spring rate. There is a more involved means of calculating frequency, which involves chassis strength, bars, etc, but the above will suffice.

IMO, every off the shelf spring kit is going to be much to soft. They are made with a strong compromise to ride quality. That said, really good shocks will make even a 700-800lb spring entirely tolerable on the street.