Setting Ride Height - Dual Rate Coilover

[4XForOffroad]

I recently had my coilovers rebuilt by @DialedShockPrep a couple months ago and I am putting the truck on its own weight for the first time with it being a completed running driving vehicle. They’re 10” coilovers and I have 500 over 600 lb springs. The truck isn’t caged - it’s a dual purpose truck I’d like to drive to the desert, explore, and get back home with. After reading his 50% up/down travel for non-race trucks, I know I need to shoot for 5” of up and down travel on the shock shaft.

What I’m not sure about is preload on main vs. tender spring and reaching that ride height. I know he says something like 1-1.5” of preload on a spring is “good” (I remember screen shotting something like that but I can’t find it on my phone to fact check myself). But how do I pick the ratio of preload between coils to achieve the proper ride height? FWIW it’s a 4x4 A arm truck and it’s got 6” of up travel out of 16”total in the rear so I am addressing that with an HD leaf pack I have waiting around for it.

I’m ok with a smidge less than 50% up travel as I don’t mind a bit lower rode height overall but if that’s a bad idea, I don’t mind going with the 50% up.

 

[2012SVTSC]

So do you have a cross over nut on the coil over or just dual spring in a stack with no cross over?

If you dont have a cross over a 500 and 600 spring stacked is really a spring rate of about 275lbs/in.

Got a picture of your setup?

 

[DialedShockPrep]

I recently had my coilovers rebuilt by @DialedShockPrep a couple months ago and I am putting the truck on its own weight for the first time with it being a completed running driving vehicle. They’re 10” coilovers and I have 500 over 600 lb springs. The truck isn’t caged - it’s a dual purpose truck I’d like to drive to the desert, explore, and get back home with. After reading his 50% up/down travel for non-race trucks, I know I need to shoot for 5” of up and down travel on the shock shaft.

What I’m not sure about is preload on main vs. tender spring and reaching that ride height. I know he says something like 1-1.5” of preload on a spring is “good” (I remember screen shotting something like that but I can’t find it on my phone to fact check myself). But how do I pick the ratio of preload between coils to achieve the proper ride height? FWIW it’s a 4x4 A arm truck and it’s got 6” of up travel out of 16”total in the rear so I am addressing that with an HD leaf pack I have waiting around for it.

I’m ok with a smidge less than 50% up travel as I don’t mind a bit lower rode height overall but if that’s a bad idea, I don’t mind going with the 50% up.

On main and tender setups, you’ll set ride height with the crossover rings, and then droop the truck out and add 1” preload to the main preload collar. You can add more preload with the main collar, you just want to ensure that it won’t coil bind aka the slider stop rings lock out the slider before the upper coil binds up.
50-55% shaft at ride height is ideal for Prerunner play trucks, race applications i aim for 55-60% showing at ride height. This is also in reference to the bypass shafts since they are the shocks that are position sensitive, not just speed sensitive.
I have set up a ranger with 5” of shaft showing on the front of a beam truck, and it worked quite well, but would have been much better with more shaft showing at ride height.
It’s all a loose rule of thumb with these equations and there is definitely more to it than just sticking to those numbers but it will get you in the ballpark of having a good working truck for sure.