What rate springs should I buy?

[2yellow69]

Hello all!

I am changing EVERYTHING on the front of the car. Hopefully someone can give me a good spring rate to start with. My problem is that I don't know what the car weighs so the calculators I have found don't really help. I figured I would list the components I have and maybe there would be someone with a setup very close to mine. Or maybe one of the suspension gurus would point me in the right direction. Here's to hoping!

All steel '69 Camaro (non RS)
Factory sub frame modified for coil overs.
Global West uppers and lowers.
Varishock coilovers.
Hotchkis hollow swaybar.
ATS aluminum tall spindles.
Unisteer rack and pinion.
C5 front brakes including the master and booster.
Smoothed firewall. No A/C yet, but the future will be nice and cool.
Iron block 6.0 LS (LQ4) with aluminum heads and composite intake.
Modified DSE frame stands and mounts to push the engine and tranny back a bit.
Aluminum radiator with Gen 4 Camaro fans.
TKO 600 with Lakewood scattershield. (hydraulic throwout bearing).

If there is any other information needed I'll add it. I have some 650 lb/in Eibach springs I was going to use when my plans were for an all iron big block but I'm thinking the car will be quite a bit lighter now.

Thanks for your help!

[Rod]

depends on the spring company you use, shock used, number of threads on the shock body, shock stroke (resting and extended) but the easy answer is if you use the Ridetech Hyperco springs the rate for your car is #650 - 8inch tall, that is an Iron block LS in a 69 camaro with the ridetech shock setup

hope that helps

[2yellow69]

Rod,

Thanks for your answer. The shocks are part #11111-515 single adjustable. The Eibach springs I have now are 10" tall. I was thinking of buying the Chassisworks springs to go with the Varishocks. The total stroke is 5.15". I won't know the resting part until the car is put together. Looks like it has 27 threads covering just 3.5 inches of the body. Chassisworks recommends a 12" spring for this shock but I don't think I'd be able to lower it much with that. I was thinking of their 9" spring and using the .75" extended upper spring seat to give me more clearance under the Chicane cage. With the spring seat I have now the seat is about 1/16" from the cage.

[Josh@Ridetech]

Take some measurements and plug them into our spring rate calculator. Like Rodney said, with our coilovers on a first gen, you normally see an 8" 650lb spring with a small block. Depending on what you're going for, you can always bump up the spring rate for a more firm ride/performance type setup.

http://www.ridetech.com/tech/spring-rate-calculator/

[2yellow69]

Thanks for your response Josh. Using your calculator and guessing at 990 lb front corner weight with me as the driver and 110 lbs of unsprung corner weight it shows 450, 475, and 525 lb springs. That's with a 5.15" stroke shock and 12" springs.

[Carl @ Chassisworks]

Hi Matt,
We can easily get this figured out. Did you try calling us to have our tech guys help you figure it out over the phone? We answer questions like this all day long.

The VariShock 5.15" travel shock is typically used in a rear application and the 4.25" is used in the front. Normally what you would do to get a longer mounting for the 4.25" shock is to change the top eyelet for one of our extended reach eyes. However, since you already have the 5.15" travel shocks we can still work with that.

Here's what we would like you to do. Stick the 10" spring that you have back on the shock and run up the preload collar until it just barely takes out the slack. Then lower the car to the ground. Measure the shock from eye to eye and also measure the compressed length of the spring. That will tell us how much weight the shocks are going to see at each corner. Either post that information here or give us a call at (800) 722-2269.

Off the top of my head, and our senior tech guy's, a 12x450 is probably what you need to hold the car off the ground. However, a 12x450 isn't necessarily going to be the right rate for handling performance. A pair of the extended spring seats (http://www.cachassisworks.com/p-2296-varishock-upper-34-extended-and-lower-spring-seats-pair-for-2-12-id-coil-spring.aspx)may be in order. In fact the more we talk it over, assuming you want to retain the current 5.15" travel shock length, your best bet may be to use the extended spring seats and a 550lb x 10" spring. We don't make a 10" spring because none of our shocks were designed with it in mind. They are commerically available from many reputable (and several not so reputable) spring companies.

HOWEVER, NONE OF THIS IS RELEVANT UNTIL THE CAR IS COMPLETELY ASSEMBLED AND READY TO DRIVE DOWN THE ROAD! So keep that in mind and let us know what you come up with.

[2yellow69]

Thanks Carl!
I guess it won't kill me to wait awhile longer since the car has been off the road for 7 YEARS now. That was actually a little hard to think about. It was supposed to be a simple BBC engine swap weekend. Oh well. I'll just stick the springs I have on the Varishocks until it's road ready. My goal is this summer, but I'm not gonna cross my fingers.

[Carl @ Chassisworks]

Hey Matt,
Yeah, I know the feeling. My El Camino has needed 'minor electrical work' and a new trans kickdown for about six months. I finally brought it to work so she can stare me down every day and ask why I'm not working on her. Poor thing.

Let me know when you're ready to go into detail on your shocks!