front coil overs

[paubuchon]

I'm building a cobra replica with a mustang II front suspension, 5.0 motor with steel heads and 5-speed. its a pretty simple car being built on a budget. i'm wanting to run front coil overs and was wondering what spring rate would be good for a street car with 16 inch wheels.

[avdcav]

I'm using qa-1 with 500 pound springs " rides great
But I also have a 460 so I wanted some stiffness

[mickmate]

I would put strut rods in while you build it. Make up something like this Shock Mock-ups : Kugel Komponents, Quality Komponents Since 1969 from a piece of square tube or angle with holes drilled through it.
Weigh it when it's done and measure the control arm lengths. Put your numbers in a calculator or call your chosen brand shock for application info.
Spring Rate Calculator « Ridetech News and Information

[paubuchon]

made some simple adjustable struts, i'll weigh it when im finished mocking everything up. thx

[mickmate]

If the strut rods are made to ride height you have an important first number to calculate what shocks.

[Ant]

Originally Posted by paubuchon

made some simple adjustable struts, i'll weigh it when im finished mocking everything up. thx

As Mickmate said measure the control arm length.
Control arm length "Motion Ratio" is total pickup point measurements and the measurement of where the shock is mounted on the lower arm in relation to the other measurements, if the shock is mounted close to the suspension upright you will require a softer spring, and firmer if its mounted closer to the inner pickup points.

Weight is taken into consideration and if others are using a certain poundage spring then it would have to be the same design or make as yours with same suspension points and usage. Some people use 700Ib front springs, my car is solid on 400Ib springs and its a track car, the only answer is do the maths etc.