Long Travel BS Thread

incorrect lower coil seat could def be your prob

 

he's a 1st gen. They can get away with it.

 

Is that pic of yours at ride height?

 

I think "incorrect" coil seat is not exactly the right way to put it. Because Solo uses about the same rod end (I have) and a coil seat with no lift for 2wd (same kit but they don't have to clear the CV)

A different coil seat (and rod end length) could be a reason why I could clear an 18 inch coil.

The coil seat/rod end I have has no problem clearing the CV axle.

 

Yes. And I still need to adjust the ride height up about .5 (overall... bumper height) to get it where I actually want it.

*** EDIT*** But looking at that picture right now. I really like the CV angle lol
I will actually have to probably bump it up a half inch or so though, because I don't have any of my skids on, and that weight will probably bring me down about a half an inch.

 

Just so I understand, the coil is completely unloaded at full droop? To me that very much sounds like you are limited by spring rate/ ride height. you are adjusted to the ride height you want but not enough preload to satisfy the full range of the coil. Heres Eibachs spec chart I found, Fox or kings should be pretty similar. a 16" #650 should compress about 8".

Quickest option: Preload coil enough to satisfy the range of motion (16" top preload collar to lower coil seat) obviously this will raise your ride height
second option: I might be wrong in this assumption but if you want/ need to stick with #650 it sounds like you may need a longer coil, as long as you have room for it on the shock body. You are bump and strapped so you should be able to get the ride height & travel without coil bind.


Edit: Im running King 8" Coilover with 16" #600 spring. have not had any travel issues yet. need to redo my alignment though. I just got my TC LBJ uniball conversion to convert to full Heim Steering. the stock oTREs were hitting my bypass mount tabs on the LCA

 

I'm not talking about CV clearance I'm talking about the fact that your spring is turning into a dash board hula dancer at droop. " incorrect " "wrong " " not the right one " you pick which word doesn't hurt. The only way that would be happening with the correct CO config is if you were trying to set up your truck with a really low ride ie: nowhere near " neutral " / equal comp vs droop. I went through the same crap when I had a Solo kit ...they said " just buy a standard 8" CO ... when in fact I needed a different lower rod end, different misalignments, a different lower coil seat and a different resi hose config at the top hat.

 

LMFAO... Setting the truck up to have equal comp vs droop would be dumb. First of all, I'm more concerned with droop travel than up travel because I'm mainly in the rocks. But if you set up a 1st gen to have equal up and down travel, you'll be nose up with a Carolina squat and I'd say your CV angles will be pretty much fucked. I could solve this problem (loose coil at droop where the straps limit) by cranking down the preload collar, which would lift the truck to basically even comp and droop... but then my CV angle (at ride height) would be garbage.

The coil seats are already an inch and a half taller than the standard Fox seats. The resi elbow has also been changed. Not sure what you're talking about with the misalignments because the lower shock mounts don't need misalignments. They are the same size as the rod end's eye (shock mount).

There are a ton of different combinations to get LT to work for the application. Different coil rates, coil heights, coil seats, rod ends, pre load settings all can address this problem. I'm just trying to figure out which one addresses it, the way that works best for my application. To say it's all on the coil seat and that it must be "incorrect" is only looking at about 1/10th of the situation. Yes adding about 1/2 inch to the coil seat would probably fix this. But a half inch taller coil seat isn't an available option here. I already had to order the two piece coil seat, I have, directly from Fox because they don't list the part numbers in their catalog to retailers.

 

How much do the 650 lb springs compress with no preload at ride height? The amount they compress X the 650 lbs/inch spring rate will give you the static load on the springs.

Leys say the 650 lb springs compress 2.3" with no preload because you have a heavy truck and the front weighs 3,000 lbs, then 550 springs will compress 2.73" with the same load. To achieve the same ride height with a 550 spring would require 0.43" of preload

Can you fit an 18" spring with 0.43" of preload, or if you think you need to raise it another 0.5" to compensate for the skids then that is another 0.25" of preload so 0.68" of preload.

The minimum compressed length of an 18" spring I found is 8.5"

Based on this you could have up to 1.5" of preload to still maintain 8" of travel. If you exceeded 1.5" of preload the spring will bind out before the bump stop bottoms out.

https://www.kartek.com/parts/silver...-king-sway-a-way-or-fox-coil-over-shocks.html
Eibach Part Number:
1800.300.0550s
1800-300-0550s
Length: 18 Inches / 457mm
Inside Diameter: 3 Inches / 76mm
Spring Rate: 550 lbs/inch - 9.82 kg/mm - 96 N/mm
Full Compressed Height: 8.5 Inches / 216mm
Travel: 9.5 Inches / 241mm
Load At Full Compression: 5231lbs / 23269N
Weight: 14.33lbs / 6.5kgs

 

Damn dude! BRAVO... That's a bunch of math that's well above my pay grade, but that makes sense.

I absolutely have enough room to get an 18 inch coil in there, because the added coil height would cause the preload collar to move. Right now I have about 1.5 inch of thread above the preload and another .5~.75 inch between the top of the coil and bottom of the preload collar -> when the coil is unloaded off the truck... I also have about .25 inch that I'd need to adjust the collar down to account for the skids.

If I read that right, you're saying I would have to preload the 550# 18 inch coil around (just shy of) 3/4 inch which would also actually help me out. It sounds like (according to math anyway) I could fit the 18 inch coil and have somewhere around .75 of preload and be golden.

 

When you are talking about "no preload" you seem to be talking about thread showing measurements. when it needs to be in relationship to the spring length regardless of the threads showing.

The second part is, that the load calculation needs to include the motion ratio of the lower control arm. It is not 1:1. however, you do not need to calculate the motion ratio for just a spring change.

Take a measurement of your current spring length with all the weight on the truck, then at extended length, measure the spring. then add the preload length to get the effective spring rate.

Example:
16" Spring rate of 650 lb/in
spring length and ride height: 12"
Spring length at full extension 15"
Preload of 1"
the spring has been compressed 4" inches total at ride height, including preload. 1950 pounds of truck weight (3") and 650 pounds of preload (1") = 2600 pounds

For a 550 pound spring to hold the same ride height, 1950 (truck weight) divided by spring 550 (spring rate) = 3.54" of spring compression, plus preload compression of 1.18" (650/550) results in the spring compressing 4.72".

If you kept the same 16" spring, you would need to set total spring preload at 1.64" (4-3.54= 0.46 then add 1.18"= 1.64")

swapping to an 18" spring, you would need to remove preload 2" of preadload as the spring is longer by 2". However, based on these calculations, there is only 1.64" of preload so you would have to add a negative preload of 0.36" - which physics do not allow, means that making this spring swap in this example would result in a higher ride height.

*this also assumes a 18" spring fits over your coilover without any preload - if you are using a 8" stroke shock, odds are that an 18" spring will not fit without inducing preload.

 

I feel like springs need to be tried out rather than debated. Only so much you can tell over the internet with so many variables on trucks and coilovers.

I recall accutune had a pretty good deal on spring swaps if you’re local.

 

to a point, yes, that is why I responded with a way to measure and calculate based on however his truck is set up. I removed all other variables and only looked at spring lengths to back into the calculation rather than using motion ratio and truck weight. That doesn't work unless you know everything, including the sprung and unsprung weights.

 

My math above neglected to account for motion ratio, but as you said you do not need to calculate the motion ratio for just a spring change. The motion ratio on the stock IFS is around 0.54 with LT it will be a more like 0.5 or so.
In my example with 3,000 lb on the front (1,500 per side) the 650 would compress (3000/650) 4.6" and the 550 (3000/550) 5.45"
This means to with no preload the 550 lb springs would sit 0.84" lower than 650 with no preload

Right now he has in effect "negative preload" on the 650s and at full droop they are flopping around because the distance from the preload collar to the lower spring perch with the shock at full droop on the limit straps is more than the length of the uncompressed 16" spring. This is in effect already "negative preload" if you will.

If he threaded the preload collar down 0.5"-0.75" to the top of the 16" springs that would raise the truck by 1"-1.5" ( 0.5 motion ratio) which @El Taco Diablo states is too high, but he also said once he adds the full skids it will sag about 0.5" from his experience with his old setup, with the 550s it will likely sag a bit more.

Sounds like with the space between the top of the spring and the collar, and the threads above the collar there is an additional 2" of "slack" available to mount 18" coils with no preload.

650s with a true zero preload and no slack would be 1"-1.5"" too high

Based on a 2,500-3,000 lb front end that would compress the 550 lb springs 0.7"-0.84" more than it was compressing the 650 lb springs making the truck 1.4"-1.7" lower than with 650s with zero preload.

Based on this I believe @El Taco Diablo can achieve his desired ride height with 18" x 550 lb coils with 0.25'-0.5" of preload

I also agree with @Supra4x4

 

I did the work sheet for Accu-tune earlier. According to them, your math is dead on, because they are basically saying everything you are saying.

I think 550# at 18 inch is the way I'm going. This conversation is exactly what I was hoping. I think it narrows it down to me not having to buy a bunch of coils I don't want or need



And for the record... Accutune didn't care about or even ask about the coil seat.

 

Been a while since I’ve posted in this thread. Cage build is moving along great, I really cannot wait for this to be all done and the snow to be gone!

 

How I’m feeling now trying to read this. It’s Friday and I have my own truck to worry about putting back together tomorrow before storms hit and we get a foot of snow

 

@906taco I love how the middle back passenger gonna have the xtra oh shit grab bar. thats gonna be the best ride in there.

 

very nice work. It’s coming along and looks great.