Coil Spring Calculators

[fluidfloyd]

This is for those of you that are building cars that use coil springs or coilover shocks. If you buy a kit it will usually come with the correct spring rates as decided by the manufacturer. But if you are building on your own then things can sometimes get confusing. When choosing springs there are a number of factors to consider and at time it just cause your brain to hurt. I am at that point as I speak and since I'm working through this I thought I would post these two links that can be of great help. You can sit down with a hand calculator and run the numbers or you can use these online problem solvers. The first site will be of great help in determining the spring rates that you might already have on hand.

http://www.pontiacracing.net/js_coil_spring_rate.htm


This second site will help you in shock/spring placement.

http://www.proshocks.com/calcs/index.htm

You still need to use common sense in mounting things but these two tools will be of valuable assistance to some. One other point. If you are doing a custom design and you need technical help from the spring source, always call and ask for someone in engineering. Sales people usually can't give you wire diameter, number of coils or anything not shown in their catalog. I hope these will help you at some point.

George

 

[Ted Brown]

George, Thanks for the posting of this info, this should help a lot of the fellows learning about suspension... as far as racing on the drag strip goes, I have found that what the Calculator says is right, in practice does not always get the job done, but it is always a great starting point, and that is what this site needs a good starting point... Happy crusin, ride safe, drive in a straight line when hard on the pedal.. hehe

 

[AZCOWBO]

Ditto? Before I joined the tbucketeers forum, with its fantastic membership, I contacted every shock manufacturer on the web. Every response differed in some way, except a formula forwarded to me. The only problem is, I taught math and algebra for nine years (a long time ago), and still couldn't solve it. Since it is a Jag. rear end and I was trying to get my driveshafts exactly horizontal (which isn't necessary, according to Ted)), I was going nuts (or nuttier). Ted and KC, who both have Jag rear suspensions, came to my rescue by sharing their expertise and photos. I haven't ordered my shocks yet, but Jerry at Pete and Jake's, was most helpful and willing to listen to my story, analyze it and provide me with the solution. He called his manufacturer and they will build anything I need, and they are reasonably priced. It is not like this is the first T-bucket constructed. even tho to me it is, ha. Hats off to Ted, KC, and Jerry, at Pete and Jake's. I measured and cut 4 pieces of 1 x 2 in half, lengthwise, screwed two of them together, measured and drilled holes until I attained my desired ride height. A piece of cake, when the members, give us novices a hand.

Thanks Guys,

Ron

 

[GlenC]

Thanks people! I'm still at the 'dreaming' stage but I know what I want and the rearend will be vertically coil sprung, so this will answer a lot of questions.

Cheers, Glen.

 

[kqql]

I always used Corvair front coils, problem is they are hard to find now. The boneyards were filthy with them when I was a kid! If anybody has a set and wants to sell them let me know!!

 

[Youngster]

Tip; If you can find one, use the coils from a Chevette instead. They have a tapered wire for a variable spring rate. Softer riding than the 'vair coils.

Ron

 

[kqql]

Got your plans, never tapered the rails before. Building it now I like the way it looks, it looks like it supposed to not to bulky!!

 

[T-Test]

I always used Corvair front coils, problem is they are hard to find now. The boneyards were filthy with them when I was a kid! If anybody has a set and wants to sell them let me know!!

I have been using Speedway's coil springs, 5" diameter x Spring rate wanted. Mustang II 175 - 200 lbs works good for me. Not to harsh, haven't bottomed out. May not find them in the T catalog, but in the streetrod and racing ones. Powder coated or chrome. Mounting on top of axle or in front of axle is best for ride comfort. Good luck!

 

[kqql]

Tip; If you can find one, use the coils from a Chevette instead. They have a tapered wire for a variable spring rate. Softer riding than the 'vair coils.

Ron

Ron
Thanks for the tip. Found new Moog variable rate set on E-Bay. Cheaper than Speedway

 

[kqql]

Ron
Thanks for the tip. Found new Moog variable rate set on E-Bay. Cheaper than Speedway

Ron,
Any idea what the step should be, I've got a Total performance spring behind front axle I plan on using a reversed eye spring. Thanks for your generosity and help with your knowledge.

 

[Youngster]

Boy , it's been a long time since I used coils. If the coil pocket is in front or behind the axel I would say a 6 or 7 inch kick would give the car a nice rake. That's with the coil sitting on a plate welded to the bottom of the housing. If you are mounting them on top of the axel you will need more kick to get the rear of the car to sit right.

Given most axel tubes are around 3", a coil mounted on top of the housingwill need a 9 or 10 inch kick to get the same stance. A kick like this will eat up a lot of the space in the pick-up box so I would recommend the first option. bpickett is right about mounting the coil in front of the axel. As ol' Ted would say, " think about leverage".

Ron