What spring lbs to use for Coil over for rear suspension?

[Icekottarinn]

I have Triumph Spitfire Mk3 and am modifying the Rear Suspension to Coil overs.

How ever I am not sure what spring lbs I should go for. I use the car for race/fun and road.

I did some search and found two owners of Spitfire who are using 200 lbs and 250 lbs (for GT6)

Can anyone help? Preferable the ones who are racing, but any good advice appreciated.

[rampant racing]

if you are using adjustable shocks then you could go a bit lighter say 150-180 and crank up the adjustment to stiffen the ride or tighten up the adjustment washer under the spring to raise the rate a bit. the shock must be able to work to be effective and too heavy a spring will not allow that. a rear sway bar will go a long way to keeping it from swaying about rather than a heavy spring. just my opinion. what spring rate do you use on the front? if stock then you do not want a stiffer rear spring rate or you will spin out or oversteer more easily. what is the stock spring rate if that is what you are using?