I'm building coilover struts for my 1200 ute. It has L20b installed so is heavier than a series.
Can someone with this setup help with which spring rate they are using and how it drives(harsh or soft)
Shocks are 300zx and its for daily driving and spirited cornering
Stock springs (with a series) are around 90lb/in (if memory serves me correct)
I've heard 250lb/in rides harsh.
So I'm thinking 175-200lb/in is a good comprimise. Would love to hear from fellow owners before I take the plunge.
I should add that I'm running 165/55/R14 tyres (which might add to the harsh ride of a higher spring rate)
Also tender or helper springs: Needed/recommended or not?
Input apprieciated

I've got a 120Y with L20 in it. Currently have 175lb front springs (Kings 260Z low springs) on 120Y strut with 1200 strut top. Very comfy ride on the street and ok for spirited cornering, but you'll get a bit of body roll. They are too soft for track work with grippier semi slick rubber. If you've got coilovers as it sounds, I'd go with 200lb. Wouldn't go much higher unless you've done something to stiffen the rear, or you'll end up with loads of understeer.

Also take a look at single (or double) taper coil spring range from kings. The spring rate increases with compression. I run a set in my sedan, the first inch of travel is ~ 150 lb and rises from there. I think the technical data can be found on the king spring web site.

As for linear springs I was going to suggest ~ 225 lb/ in. Which is in the same zone as Harry suggested.

Thanks for the feedback gents. I'm leaning towards 200lb/in. linear kings. Yeah they are custom coilovers similar to datsport http://www.datsport.com/strut-dsk2005.html
The rears are lowered reset leaf springs and are quite stiff. Hopefully understeer isn't a problem (I would rather oversteer any day)
I'm gonna put them in without springs to see where to weld the threaded section on for optimum capture and stance. Then measure from top hat to adjustable spring perch(centered on the thread) to get length of spring correct. That way I can lower or raise the front end an inch either way when they are installed.
Do you guys recommend wiring the spring to the hats to keep it captured at full droop?

While you have the strut installed without the spring, take measurements of the available suspension travel, droop and bump from ride height. With those measurements you can estimate the likely hood of the coil spring binding or not; as well as the spring remaining captive under full droop conditions. Also take note of the angle the lower control arm is at the preferred ride height. Ideally you will want to retain some angle in them. Knowing the corner weights or at least the weight over the front axle very be also very handy working the suspension out.

Cheers

Will do benny. Thanks alot I owe you a beer

Finally got these done. Went with King 225lb, 180mm. Couldn't be happier. Now to fit Bluebird S2 disc over drum rears

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Right on. King says they will lower a 1200 by 25mm. How did yours turn out?

Just threw up the photos. Removed the spring perch. Welded on threaded collar. Used the 200b top hat. Had to file out the mounting holes a little. All is golden!