Coil Over Spring Rate?
 

I know your going to ask what is the weight of the car. Well I'm going there 2day to check (if it stops raining). I have a back half Chris Alstons rear, with the stock non-adjusting springs in the rear. I'm wanting to upgrade the shocks and springs. I remember seeing a site, that told me what springs to use for what lbs of car. After I get the car weight I'll repost it is a street car/ race 63 Pro Street Nova... BBC/Auto If you know the site with the spring rate for lbs of the car Thanks..

rain/rain Well I have not got it to the feed store to get the weight. I was wishing today, but still rain. I know the weight will not be exact but should be close. I found a site, for a car at 2775 lbs. is 225# spring, 3175# is 300#, and 3650# car is 450# spring. I'm thinking my 63 Nova would be over the 3000 lbs. but not 3600 lbs. , but who knows. I'll get back with yal.. Thanks

Just a suggestion.My Olds weighs 3125 total .I'm 1470 at the rear wheels.I have double adjustable shocks with 12" coils.Strange recommended I use a 175lb spring RJRacecars(who I bought the shocks from)suggested a 125lb.I went middle of the rodd and got the 150s.Reason I am telling you this is with the adjustable shocks I can turned the compressoin setting all the way off/free and those 150lb springs won't even let the car bounce!!It is so dang stiff that I can jump on the back of the car (I'm 240lbs)and it will hardly move at all.My buddy has a 70 Chevelle with 85lb springs on it,and it seems to be about right.Just food for thuoght. :D

Where the shock is located in relationship to the rear axle will have an effect on the rate. The amount and how much of an angle it's mounted will have an effect. It's not just a matter of how much the car weighs. There is a formula for figuring the rate but you will need the rear weight and the shock location and angle (if any) to get a baseline.

That makes perfect sense....way over my head,but perfect sense

Well I made it to the feed store. Got my weight front 1690 lbs, rear 1620 lbs, with total 3330 lbs. (I'm missing 20lbs) I know the front/rear might be off alittle but it's close. My shocks are at 0 angle sitting stright up and are behind the rear end. Any help?

What type of rear suspension does it have? You said it currently uses a stock non-adjustable rear spring which on a Nova would've been leaf springs. It sounds like an odd setup. Most backhalf cars I've worked on use a coil over shock to start with. If it is a leaf and you're going to coil over do you know how far behind the rear axle the coil overs will be? Also if you're removing a leaf spring there's a good chance that it doesn't have a track locator on it because a leaf spring will keep the rear in place. If this is the case you will have to add a track locator of some type.

He said the car has a Alston hack-half,so I'd assume that they didn't reuse the stock leafs for that.I think what he means is that his shocks are non-adjustable.Does it matter how far off the axle it is?I mean aren't basically all coil-over mounts the same distance off the housing.Plus the leverage against the spring will be dependant on the length of the control arms/ladder bars/four links.Just my opinion.And most all ladder bars are 33" center of the housing-center of front rod-end,so that removes another variable.If I were you,jjam,I would call Chris Alston and talk to them,since it's their suspension.They built it so they know all the angles and such...you can't beat a man at his own game!!Good luck!!

I'll try to call them 2morrow, maybe they can tell me what springs to run. Or find a chassis guy to tell me what springs would be best. Thanks everyone with the help.

Called chassis works and they told me just to use my old springs, with my new shocks. I guess I'll find a chassis tuner later. Thanks