http://www.pirate4x4.com/tech/billavista/coilovers/Part_1/

 

http://www.pirate4x4.com/tech/billavista/coilovers/Part_2/

 

I understand the theory and have read through both of those. I am looking more for some advice from those running something similar and what they have learned through the process since theory doesn't always work.

 

since theory doesn't always work.

In this case, I'd argue that the theory does always work - but it's the application of the theory that gets difficult.

I aluded to your problem in the article, which is, "I know how to get what I want, but I don't know what I want".

I feel your pain.

I'm still hoping that eventually, we as a community, will begin to develop a list of frequencies that work well for different terrain.

That way we can trade frequency advice, which is nice because it's independant of setup, and then you can use the tools in the article to help you achieve the frequency you've selected.

Bit of an uphill battle at the moment though.

 

This may or may not help you, but take a gander at my build. http://www.pirate4x4.com/forum/showthread.php?t=582469

I'm running 200/300 but I never did any math or calculations...I just threw them in there and hoped for the best. I'd say that if anything, its a bit stiff on the road, nice for crawling, too soft for desert racing without front bump stops, fine for desert stuff if you've got front air bumps. It really will depend on you and your set up, so I don't know if you're gonna find anything usefull by other peoples set ups. Depending on your rigs weight, the angles you mount them at in the X,Y,Z planes, your valving, and a ton of different variables, 200/300 may be WAY off for your rig. I like it fine enough, but it could be tuned a little better for my taste. I also think it has a lot to do with your control arm set up....3 link, 4 link, radius arm, and the associated values of each set up. I have radius arms and they seem to have a bunch more anti-dive/anti-squat built into them than 3/4 links do, so that WILL effect how your coilovers work. So I guess what I'm saying is, you're gonna have to either post up EVERYTHING about your rig or you're in for a bunch of long nights figuring things out. Good luck.

 

I'm running 250/250.

 

Way to make use of that dual-rate hardware. :laughing:

 

Doh. :homer:

 

Hmm, guess I need to re-read the tech write ups. Much to mull over now.

 

I am going to be getting 200/300 for 16inch travel shocks in the front and 14 in the rear. After playing with the calculator for about 2 hours I think I know what I need. Oh and with the calculator you need to put your front or rear end weight and not the corner wait. If I plugged in the corner weight it said I needed 100/175. There was no way that was correct so I looked over all the numbers and correctled my dumbass mistake.:homer:

 

Just curious, but how are you all getting your corner weights? I know I can get my total weight at a truck scale or somewhere, but where's everyone getting their corner weights from?

 

That's actually the easy part. If you know your spring rate, just measure how far the spring compresses.

 

Total weight of the rig - axle weight - wheel and tire weight = Corner weight

I just looked up the weight of my axle, went onto Interco's website for the tires and weighed my wheels that i have sitting around. Remember to add steering parts and other links too. Those little things can add up pretty quick. Rams, joints, arms, etc...



Andy

 

You must like doing extra work. :laughing:

 

I'm sure mine in the front is lighter than most, and I'm running 175/300. One of the problems you're going to have is getting an initial spring rate that is soft enough to compress that 18" coilover to reach your ride height. My XJ buggy with the 175/300 springs is a 110 primary rate, and compresses my 12" shocks 6". You'll need a primary rate that will allow your shock to compress enough to reach your desired ride height, yet not be too soft. Looks to me like you'll need a 3rd tender coil so you can go with a higher initial spring rate. I'd do some calculations using around an 800 lb corner weight, and see what you come up with.

For example, if you figured an 800 lb corner weight, and wanted to set the ride height with 8" of available suspension compression, that means 8" of shock shaft showing, then the springs/shock would be compressed 10" (from full extension) at your ride height. 800 lb corner weight divided by 10" of needed spring compression would give you a primary rate of 80 lbs/in. That's pretty soft, too soft, and if you figured the frequency it would be very soft. Now, if you used a 3rd tender coil, with no spring rate, and shorter coils, you'd compress the shock 4" with no spring rate, so now you'd need to compress the springs 6" (rather than 10") to reach your desired ride height. So take the assumed corner weight of 800 lbs divided by 6" and you come up with a primary rate off 133 lbs/in, which is much better and could be close to what might actually work. BTW, your idea of 250/300 is a 136 lb/in primary spring rate.

I know this is a different subject, but 18" is a lot of travel in the front, are you sure your steering and drivelines won't bind with all of that travel?

 

One of the problems you're going to have is getting an initial spring rate that is soft enough to compress that 18" coilover to reach your ride height.Looks to me like you'll need a 3rd tender coil so you can go with a higher initial spring rate.

Thats what I need to do Im gonna use a 6in tender and go with a spring rate that can give me 5.5in of uptravel with the tender fully extended at drop.

My coilovers (ADS) you have to take the end cap off to get a second slider and tender above the slider stops. Many other shocks you can un screw the slider stops off the bottom of the shock but mine was not machined that way.

 

TGhe only bind will be in the driveshaft if any and I'm going to run a wristed radius arm to try to keep the pinion in check. I have full hydro steering so there wont be any problem with steering bind.

 

What kind of u-joint at the t-case output?