What is the proper way to set this? (see pic) Is there a formula I should be using to set the amount of use in the upper vs lower springs?

Thanks for your help.


Click to view attachment

One way is to measure the diameter of the spring, lets say it's 1/2'' . So then you multiply that to the amount of coils on the spring, lets say there is 12 coils. So now you have 6'', so measure down from your bottom spanner nut 6'' or just over to be safe 1/4''. Just remember your coil slider is going to hit that nut, so just have that 6'' or 6 1/4'' in between the bottom of the lower spanner nut and the bottom of the upper coil where it sits on the slidder. This is NOT the perfect discription, but it should help you figure out the basic understanding of trying to keep your upper coil from coil binding, or from what its looks like in the picture you are a long ways from that. Hopefully this helps you out. This is only my second post, but I have been in this industry fabricating for a while.

Oh yeah! And thier is a few more things you have to take into consideration when doing this, but i'm sure you will get some more reply's.

Wherever you set it look at the springs and inspect the surface to check for coil bind. If there is scratches you need to raise it.


Brandon

Was that pic take at ride height? I hope it wasn't taken at full droop. I would raise it a bit, since it looks like you are on your secondary spring rate right off the bat. I can't remember which way the sliders are supposed to be installed, but you might consider flipping yours over or cutting an inch or so off the top so you have some useable travel on the softer primary springrate. I have mine set at about 1/3 the way up in the bumptravel from ride height.

An easy way to check for coilbind is to put a ziptie on a couple of the coils & run it for a while. If the zipties are dinged or got pinched off, then you are getting coilbind. If you set the stop collar too low, you could also bind the secondary spring also, so look for that.

That was at ride height. I always thought the front end was a little stiff over the small chop. It dunes awesome, handles the G-outs great, but just stiff over the low speed chop. I think the car was set more for the hard pack. I did the measuring. On the front upper springs I have 3/8" coils and there are 8 of them (really 7 and the wrap at the bottom that is really like a half a spring.) That works out to 3" at full compression. I figured I would move that nut up about to a total of 4", instead of the 1 inch it has now. That should correct my chop issue, I think.

Thanks for the replies.

It will make it a LOT smoother over the chop if you move that nut up but be aware that you will bottom out a LOT easier also. I would start by moving that nut up in 1/2" increments untill you get it to ride over the chop how you like it. The rule of thumb for coils is they coil bind at half their extendend length, so make sure you do not take that nut up any higher than the top coils coil bind.

According to Bill Varnes at Mirage Racing, I was told to adjust the collar to 1-1/2" above the collector at normal ride height. I believe this meant with a normal load in it, ie 2 people in my case. This was in a rail with 20" offront travel using a 12" stroke shock and upper and lower springs being equal height.

I think 1-1/2" is a good place to start, thne move it up or down slightly from there depending on your tastes and terrain, which will of course be different than other people's tastes. Remember that this is only one adjustment, shock valving is the better method of controlling ride smoothness or travel.

Be careful with flipping over the go-between or floater. At full droop you will not want the collar riding outside of the body of the shock. If the collar is not guided by the body of the shock you run the risk of the spring deflecting and the floater not guiding properly on the body.

Keep in mind that when you set the cross-over ring to engage prior to bottom out you are basically going from a spring rate that is (Top Rate + Bottom Rate)/4 to a spring rate that is just bottom rate. (Yes I know the formula isn't quite this basic but were not talking F1 here). So for example if you have 400/600 then your effective spring rate with both springs working is 250 lbs. If you engage the cross over then you are going to have a 600 lb. spring rate.

Some tuners have a criteria for the % change is spring rate when crossing over. But for the most part my opinion is that on a buggy situation the spring rates are usually pretty similar so your not going to get a huge spring rate change.

My 2-cents would be to move the cross-over up so you are not "locking out" the upper spring and drive you car a bit to see what you think. If too soft or if you loose too much ride height then start backing it down. I generally like to make significant adjustments at the first stage to get a good feel for how it changes the car then work back to where I want to be.

More great info. I think I will take socaldmax's advice. I am going to set it at 1-1/2" with 2 people in the car. If it doesn't sell this weekend at the SSSS, I will be taking the car to Glamis the weekend of the night ride. I will adjust a bunch until I get it right. Like I said before, the car is great. It handles great, dunes great, it is just the low speed chop that is a little too stiff.

Thanks again for the replies.

You've got it backwards, if your car was set up for the hardpack the smaller bumps would be softer but you would bottom out on the g-outs.