OK, I'm trying to figure what would be a good spring rate for my coilovers on the front of my 94 Bronco with D60 front and 38" swampers. I've got 16" travel sway-a-ways with the dual rate kit. The sprung weight of the front end is 1951#. I went by the advice of the guy at avalanche and got 200# over 300# springs. And my dumba$$ didn't even calculate what that would be. Well it's about 120# which is waaaaaaaaaaay to soft. I have installed them and tested it out. It is a secondary vehicle but I would still like to be able to drive it around town and to trails. Anyone got suggestions? I was thinking more along the lines of atleast 300 over 400#, which comes to around 170# which still seems kind of light. :beer:

170lb/in is pretty soft. I don't know what you are running in the rear, superlift leafs or something? but it is probably pretty stiff. To keep it closer to balanced you may want to go even stiffer than that.

you can make it work, by moving the "rate ring" so that you are only on the 300 pound unless you hang a wheel then it would pull off of it and be in the 200 with a rate of 120.

Gordon:
you're right it is unbalanced. I think I may need to bring it up to around 250

XJJack:
Are you talking about the adjustable ring that is above the 2 coils and holds them in from the top??? If I turn it down it just raises the truck up and I don't want to go any higher. The dual kit also came with 2 smaller rings, but the guy at avalanche couldn't even tell me what the hell they are for. Are these what I need to be using to adjust the rate? :confused:
Thanks

The front of my CJ weighs about the same as your bronco and I'm running 450/450 and I really like the rate.

The only way to make the spring rate work the way XJJack suggested is to have the softer coil bottomed out completely.

So does anyone know what the 2 small rings are that come with the dual rate kit. The guy at avalanche said they were for fine tuning, but he had no idea how to use them :rainbow:

Please call me, Clifton at the Denver Avalanche(303-777-4820). I'am very suprised at the information your getting. In short you need a much heavier spring rate, the rate you have is meant for a much lighter vehical. The rings you mention are designed to allow transition adjustment from the lighter rate sping to the stiffer spring in your case. Again please call me, if you purchased Race Runners through Avalanche, I will make sure you get takin care of. :)

Originally posted by robellis77
OK, I'm trying to figure what would be a good spring rate for my coilovers on the front of my 94 Bronco with D60 front and 38" swampers. I've got 16" travel sway-a-ways with the dual rate kit. The sprung weight of the front end is 1951#. I went by the advice of the guy at avalanche and got 200# over 300# springs. And my dumba$$ didn't even calculate what that would be. Well it's about 120# which is waaaaaaaaaaay to soft. I have installed them and tested it out. It is a secondary vehicle but I would still like to be able to drive it around town and to trails. Anyone got suggestions? I was thinking more along the lines of atleast 300 over 400#, which comes to around 170# which still seems kind of light. :beer:

How are you guys getting 120# out of a 200 and 300# springs. What is the formula for that. This is something I would like to have for future reference. Thanks

Originally posted by Donovan


How are you guys getting 120# out of a 200 and 300# springs. What is the formula for that. This is something I would like to have for future reference. Thanks

I would like to know the same thing. Thanx.

To find the primary rate of a duel rate coilover:

........CM*CT
C= ------------
........CM+CT


CM= spring rate of the main spring (lb/in)
CT= spring rate of tender spring (softer or upper)(lb/in)
C= primary rate (lb/in)

Sway a way coilover worksheet (http://www.swayaway.com/Suspension%20Frameset.htm)

Originally posted by robellis77
So does anyone know what the 2 small rings are that come with the dual rate kit. The guy at avalanche said they were for fine tuning, but he had no idea how to use them :rainbow:

Ok.... the two extra nuts get threaded onto the shock housing between the upper spring mount and the nylon dual rate slider. You want to adjust the nuts (two per shock, jam nut them together to keep um from moving) so that they are about 3 inches above the dual rate slider. So if you had a 300/200 rate springs, you would run the 200 on top and the 300 on bottom. so at ride height you have a combined rate of 120, once it compresses those 3 inches, the slider hits the nuts and stops the 200 spring from compressing. From that point on you are yielding only the 300 pound spring rate.

Soooo..... you effectively have 120lb rate for the first 3" of travel and 300lb rate the rest of the way... I can't believe the Avalanche guy did not know that.... what a booozooo... :rasta:

Well, I have to say I wasn't really happy with my experience with avalanche, but it was also my fault for being an uninformed buyer. But, yesterday I got in touch with Clifton at the other avalanche store(see above) and I'm extremely pleased. He remedied all of my problems and was very knowledgeable. He explained all of the fine tuning and exchanged my coils for me. It's just such a good feeling when people don't have to do anything for you but they do. Thanks Clifton
Rob:beer:

Originally posted by robellis77
Well, I have to say I wasn't really happy with my experience with avalanche, but it was also my fault for being an uninformed buyer. But, yesterday I got in touch with Clifton at the other avalanche store(see above) and I'm extremely pleased. He remedied all of my problems and was very knowledgeable. He explained all of the fine tuning and exchanged my coils for me. It's just such a good feeling when people don't have to do anything for you but they do. Thanks Clifton
Rob:beer:

Good to hear that! A big thumbs up for Clifton @ Avalanche!

Originally posted by Eddie Mcstiff
To find the primary rate of a duel rate coilover:

........CM*CT
C= ------------
........CM+CT


CM= spring rate of the main spring (lb/in)
CT= spring rate of tender spring (softer or upper)(lb/in)
C= primary rate (lb/in)

Sway a way coilover worksheet (http://www.swayaway.com/Suspension%20Frameset.htm)

I understand the math, but I'm curious to why the dual rate is softer. Is it because the total spring length, or number of coils, has increased?

It has to do with the length of the wire. The longer the spring or the more loops in the spring the softer it will be. to get a stiff long spring, you need to wind thicker wire or spin less loops.