Looking for some advice. I am new to the world of coilovers. Scored a set of off road evolution/ king bolt on coilovers brand new in box on Craigslist.

The problem I am having is the rear end being too high. The person I had bought them from said the spring rates were the regular springs not the hd. I have a 2 door with no spare tire carrier, with stripped interior, no rear seat no seat belts... nothing except my Hutchinson with 37 inch krawler in the back.

I have completely adjusted them down with zero preload, just to see if it made a difference. It didn't. Am I having this problem because I do not have enough weight in the back? Is there a way to tell the spring rate by looking at the spring? Is there a lightweight spring? I know a lot of 4 doors run these with all kinds of gear and large spare tire carriers.

 

Why don't you call Off Road Evolution and ask them about spring rates for your Jeep ?

 

That's the next step. With my work schedule and time difference it's tough to have a chance to call them while I'm near the jeep. Just seeing if anyone had some input.

 

You can change the spring rates accordingly to whatever you need. Sometimes they ride a little tall for the 2 door. Maybe change the top springs down 25 or 50 pounds and see how it settles then.

If you want my honest advice I would call both ORE and Filthy has a nice program to trade out springs until you get the correct rate for your needs.

Best of luck, once you get them dialed you'll love them though it does take some time.

 

You can look on the springs to see the numbers. If you have a light jeep you will get a lot of lift in the back. With my heavy 4 door I had to get heavier spring rates.

 

You can't change the spring rates without buying different springs. You can change the preload but he already said he has it as low as it will go.

 

When I get home tomorrow I'll check the springs. I do know they are the lighter set ore offers. Are they labeled?

 

Yes you can get a lighter set. You probably have 200/250 now.

 

.... How else would you change spring rates? I was recommending that he contact a vendor that offers a program where you only have to buy one set of springs and if you aren't happy they will keep shipping you different rate spring until you are pleased with the rates.

 

With a light 2 door I would go with a lighter coil set up. Maybe 100 over 200 and you may need to run a shorter upper coil. When you can, measure what you have as far as shock length at ride height (eye to eye) and then jack the jeep up until the weight is off the coils. With this and your current spring rates you can figure your sprung weight and size the coils you need. Example if you have 200/250 coils your rate is 225 pounds per inch, if your shocks compress 3" at ride height you have 675 pounds of sprung weight on that corner. With 100/200 upper effective coil rate is 150 per inch and 675/150=4.5" of compression. This would give you a ride height 1.5" lower then you have now but you still have no preload on the coils. When tuning with King they start with 1.5" of preload on the coils and tune from there.

The upper and lower coils do not have to be mounted in that position so you could run a 200 lb upper in the lower position, just make sure it is as long as the travel on your shocks or the slider will leave the shock body and get hung up on the shaft. The white numbers on the coils will list the diameter, length, and coil rate. I find that the EVO set up is a bit on the heavy side and is set up for a heavy JKU.

The lower your coil rate is the more comfortable your ride should be up to a point, you don't want it so soft that you are bottoming out under a relatively mild trail, say going 40 mph on a rutted road. You will get more body roll from softer coils so if you drive your jeep like a race car you may want to have the heavier coil rate. Of course the shock valving will have an effect on theses ride characteristics.

Also what is your nitrogen pressure? The pressure can act kinda like an air shock, increasing the effective coil rate by increasing the pressure therefore increasing the ride height. I tend to see most people run around 150 psi. The nitrogen pressure will also affect your compression and rebound characteristics of the shock.

Once you find out what you have for coil rates write them down in a notebook and take the jeep for a ride down a rough dirt road, try to get it up to 45-60 mph and make notes on how it drives. Are you bottoming out? (too soft) does the front or rear end feel squarely where it is dancing side to side? (too stiff) Does it feel like the rear end is bucking you? (too stiff) Or does it have a good ride? (right on)

After that add 1.5" of preload and do it again making notes on ride. See how it changes.


Also note where your rate rings are set.

In the end if you want a generic coil over set up buy the Rebel or EVO kit and settle for the ride. If you want to take advantage of what you can get out of the coil overs then it will take some tuning to really get them dialed in.