Coilover Spring Rates

[RelentlessPursuitRacing]

Jerry,
What spring rate are you running on your Kings? Not sure yet what I'll run.


King 3" Race series Coilovers, 200 over 350.
1996 Bronco TTB. Estimating a max of 5,000lbs race ready, hoping for 4,500 and dreaming of ending up just over 4,000. I gave King the weights estimates and let them figure out the rate for me. We'll see if that was wise or not later. They will exchange the springs for a different rate for free as long as they are in "new" condition. So at least I have something to get the build going and when it is closer to being done I will have a much better idea of race weight, I will get a better idea if the rate is close or not.

[Scott]

King 3" Race series Coilovers, 200 over 350.
1996 Bronco TTB. Estimating a max of 5,000lbs race ready, hoping for 4,500 and dreaming of ending up just over 4,000. I gave King the weights estimates and let them figure out the rate for me. We'll see if that was wise or not later. They will exchange the springs for a different rate for free as long as they are in "new" condition. So at least I have something to get the build going and when it is closer to being done I will have a much better idea of race weight, I will get a better idea if the rate is close or not.

That's the same setup they recommended for our little Bronco. I think it's a little stiff, but we'll see when all the changes are finished in a few weeks. We weighed in about 4.5k fully dressed (without me and John's big asses in the cockpit!).

[RelentlessPursuitRacing]

That's the same setup they recommended for our little Bronco. I think it's a little stiff, but we'll see when all the changes are finished in a few weeks. We weighed in about 4.5k fully dressed (without me and John's big asses in the cockpit!).

Yeah, Don said the ones they recommended for them were WAY to stiff as well. Maybe they just assume we are all running trophy truck speeds....?

[roach]

King 3" Race series Coilovers, 200 over 350.
1996 Bronco TTB. Estimating a max of 5,000lbs race ready, hoping for 4,500 and dreaming of ending up just over 4,000. I gave King the weights estimates and let them figure out the rate for me. We'll see if that was wise or not later. They will exchange the springs for a different rate for free as long as they are in "new" condition. So at least I have something to get the build going and when it is closer to being done I will have a much better idea of race weight, I will get a better idea if the rate is close or not.


jerry, how much are 3" coil-overs compared to 2.5's???? if you can save some money you should run the 2.5's. there is no reason to run the 3". i believe the springs for the 2.5's should be cheaper also, saving you even more!! if you plan to run a bypass shock up front, the coil-over can be small. let the bypass do all the work.

also, this one is personal, but i am a Fox guy. i can rebuild them and change the valving as fast as i can remove them. SUPER easy to work on and the parts are cheap as hell. i think last i checked, a seal kit for a 2.5 fox was somewhere under $20 per shock!

and on a last note, brothers help each other out. i should have my truck done way before yours, and it sounds like we are building something similar, we have lots of springs sitting at work, it is how we find our spring rates as well. i have the benifit of bringing various spring rates to the desert with me until we are happy. then i can give you the specs and you can buy the same deal. 5000lb sounds a little heavy. we hope to not break the 4000lb by much.
hope this helps.

[RelentlessPursuitRacing]

jerry, how much are 3" coil-overs compared to 2.5's???? if you can save some money you should run the 2.5's. there is no reason to run the 3". i believe the springs for the 2.5's should be cheaper also, saving you even more!! if you plan to run a bypass shock up front, the coil-over can be small. let the bypass do all the work.

also, this one is personal, but i am a Fox guy. i can rebuild them and change the valving as fast as i can remove them. SUPER easy to work on and the parts are cheap as hell. i think last i checked, a seal kit for a 2.5 fox was somewhere under $20 per shock!

and on a last note, brothers help each other out. i should have my truck done way before yours, and it sounds like we are building something similar, we have lots of springs sitting at work, it is how we find our spring rates as well. i have the benifit of bringing various spring rates to the desert with me until we are happy. then i can give you the specs and you can buy the same deal. 5000lb sounds a little heavy. we hope to not break the 4000lb by much.
hope this helps.

The 3" King race series are BIG bucks...and they are HEAVY and HUGE! We'll have to talk more about this one. I'm all ears. I know just enough to get me into trouble! :) I am running 3" bypasses. I actually have to sell my coilovers and buy new ones anyway. A little mis-communication (the politically correct way to put it) and my guy ordered 16's instead of 14's and they are way too long I believe for my application.

You will definately have yours done before me. That would be awesome. I'll take all the help I can get. I know just enough to get myself in trouble. :)

I'm still hoping for 4,000, but i figured everyone always underestimates, so I figured I would over estimate and then be pumped when I come in under! :D

[straightaxle]

As far as spring rates, remember that there is spring rate and effective spring rate at the wheel. With a straight axle, they are basically the same, but with a TTB you have to factor in the swing arm. The spring rate for a TTB will be higher than that for a straight axle to get the same effective wheel rate. In the end, it still takes testing to come up with the right combination.

Cost was a big factor in the decision to go with 2.5 coilovers versus 3". Like Jerry said though, you only have to buy the original set as long as King will exchange them.

[151FAB]

I don't know if things have changed but a few years back Brett (King) told me they only exchange the coils for 2.5" C-overs and that they had to order the springs for the 3" C-overs and wouldn't exchange those.

[straightaxle]

Not sure about the 3" C/O spring exchange policy, but they have pallets full of new springs. 3" spring availability at King is good.

The Kings are not too bad to rebuild, but like Roach said, the Fox's are even easier.

[151FAB]

Do you know if your going to run the same rates on both sides of the front end?

[RelentlessPursuitRacing]

Do you know if your going to run the same rates on both sides of the front end?

Yes, I think so. Although the beam on the drivers side is heavier because of the 3rd member, I don't think it is a big enough difference to use a different spring rate from side to side. They don't make springs for every 40lb. increments of weight on a rig anyway.

[convoy]

IMHO 200 over 250 seems light to me.

BTW I'm running 3.0 triples with 2.5 c/o at 350 over 450 up front. I ran 450 over 500, but was way too stiff. Most of the work is being down by the bypass not the coils anyways.

[RelentlessPursuitRacing]

IMHO 200 over 250 seems light to me.

BTW I'm running 3.0 triples with 2.5 c/o at 350 over 450 up front. I ran 450 over 500, but was way too stiff. Most of the work is being down by the bypass not the coils anyways.

200 over 350.

[convoy]

Typo I meant 350.

I presuming the 200 is a tender?

[RelentlessPursuitRacing]

Typo I meant 350.

I presuming the 200 is a tender?

Nope. Hard to believe that KING screwed it up as bad as you make it sound.....especially given the fact that we estimated high and told them 5,000lbs. for the Racer.

[BajaBronco13]

I'll definitely have to get my vehicle weighted wet to figure out what springs I'll be running.

Jerry, any pics of the cutting up of your Bronco that you can post? Love to see the sawzall or plasma action, lol.

CP

[151FAB]

Yes, I think so. Although the beam on the drivers side is heavier because of the 3rd member, I don't think it is a big enough difference to use a different spring rate from side to side. They don't make springs for every 40lb. increments of weight on a rig anyway.

I was considering the length differances between the two sides. Assuming that the center of the tire is three inched past the upper balljoint that would make one beam 39.5" and the other 32". Now assuming that both C-over mounts are 4" short of the upper ball joint; the longer beam's springs have a moton ratio of 82% and the short beam's springs have a motion ratio of 71%. It would seem that the two sides would need differant rates of spring or the shorter beams C-over mount would need to be about 1.25" further out on the beam than the longer one to equal out the ratios. Of course wheel offset, beam extension, C-over mont location, etc would change the numbers I've used here but I'm sure you get the picture.

[steveG]

I listened in on a conversation between a friend and one of the Kings (maybe Bret?) and he was adamant that the springs should only hold the truck up to ride height and that the shock should do all the work. Knowing this, the fact that they recommend such light spring rates doesn't completely surprise me.

Of course King's opinion should be worth more than mine, but two things that come to mind....

With such low spring rates, what happens when the truck is cornering hard or is at the bottom of a long roller and it hits a bump? Because these are relatively low(suspension movement)-speed situations, the shock isn't doing much, so there's a good chance the suspension will be close to full bump. Lack of bump travel plus bumps some times ends badly.

Lastly, the front has really soft spring rates, what about the rear? Are the front spring rates going to work well with the leaves?

Whatever the case, I'd like to know what everyone ends up with and how they work.

[Moss2]

Here is a link from the competitors site that has some interesting calculation sheets. Kind of taking their word for it since it is plug in the numbers style and they dont give you the formulas to check but good to compare stuff with.
http://www.swayaway.com/TechRoom.php

I plugged in some guestimations on a TTB geometry and came up with a wheel rate about what your current spring rate is. So it may be a bit on the soft side but not a lot probably. Anyway Steve is right the softer you go on the springs it gets mushier in the handling department and gets deeper in the travel when you are on the brakes etc. So dont use the brakes in the bumps and your fine!.

[steveG]

I was considering the length differances between the two sides.

While there are differences between the two ratios (when modified with longer radius arms), you're not calculating them correctly. The beam is not a stand-alone unit. Think of the beam and radius arm assembly as an A-arm then make your calculations.

[RelentlessPursuitRacing]

I'll definitely have to get my vehicle weighted wet to figure out what springs I'll be running.
Jerry, any pics of the cutting up of your Bronco that you can post? Love to see the sawzall or plasma action, lol. CP

Weighing it all out will enable them to get it close with a guestimate, but it's always gonna take real world testing to dial it in just right. If you are VERY LUCKY, you will nail it on the first order of springs, but not likely.

[chupakabras]

that's for sure, only real world testing to dial it in just right, the math's wont be 100% accurate, one of the contstants ( weight) becames a variable, the load or weight distribution changes a lot while accelerating, breaking or cornering, so, you will have to start with something, the rest will need to be control by the shocks,. right?

also, coil overs let's you preload the shocks, so, maybe the first ones will be the one's at the end,. good luck man..

i don't know if everybody uses dual rate coil overs, most guys have dual coilovers but without dual rate, ours is 275 over 350, i adjust the shocks to use the 275 just 1.5 inches to compression from the rest position, from there, the shocks works 100% on the 350, hope i made my self clear, haha,

the photo doesn't shows what i'm trying to say, because it's fully extended, but when in flat position with tires on, the spliter o divider ends up on that distance from the limitter, ok, see yahh..
http://www.supermotors.net/getfile/537914/fullsize/king.jpg

[RelentlessPursuitRacing]

Jerry, any pics of the cutting up of your Bronco that you can post? Love to see the sawzall or plasma action, lol.
CP

Yeah, I've just been kinda teasing everyone a bit with the changing avitars....but, it is showing the progress. As slow as it may be. I will start a thread for my build in the next few days and post up pics from the start. Unfortunately you won't see a whole lot on it in the next 8 weeks. Other commitments. But, come Sept. 1, I will have a lot of time to dedicate to it. Stand by! :)

[151FAB]

While there are differences between the two ratios (when modified with longer radius arms), you're not calculating them correctly. The beam is not a stand-alone unit. Think of the beam and radius arm assembly as an A-arm then make your calculations.

I see what your saying: project a line perpendicular to the pivot axis and that length is your true ratio. I wasn't sure if that applied to the springs as well but now that you've brought it up I see how it would. Thanks.:)

[jimyz250]

I know this is an old thread, but, I am going to build my shock towers/engine cage this weekend, well at least get it started, andI want to get a basic spring rate for my 90 ttb with a standard 4" lift, ext. radious arms, dropdown brackets( they will be replaced by bent beams as money permits), it is really a basic setup, I have 12" swayaway coilovers and will mount the shock basically vertically from either the top of arm or right in front or rear (depnding on space ie master cyclinder/ a/c) and want to be somewhere in the ball park. I read this thread last night and got the impression that 250/275's over 350 would be close, I called autofab and the truck shop today, and both of em said I would need much heavier springs like in the 500 to 700 lb range. I dont want to be way off, I want to be close, and there is a huge gap in rates here. but I kind of have faith in you guys as the info I have gotten on here in the past hasnt steered me wrong yet. I know there are a few of you who have a similar set up. its a standard bronco, with a cage not heavier or lighter than most of yours.. please help...

[tnt]

I know this is an old thread, but, I am going to build my shock towers/engine cage this weekend, well at least get it started, andI want to get a basic spring rate for my 90 ttb with a standard 4" lift, ext. radious arms, dropdown brackets( they will be replaced by bent beams as money permits), it is really a basic setup, I have 12" swayaway coilovers and will mount the shock basically vertically from either the top of arm or right in front or rear (depnding on space ie master cyclinder/ a/c) and want to be somewhere in the ball park. I read this thread last night and got the impression that 250/275's over 350 would be close, I called autofab and the truck shop today, and both of em said I would need much heavier springs like in the 500 to 700 lb range. I dont want to be way off, I want to be close, and there is a huge gap in rates here. but I kind of have faith in you guys as the info I have gotten on here in the past hasnt steered me wrong yet. I know there are a few of you who have a similar set up. its a standard bronco, with a cage not heavier or lighter than most of yours.. please help...
Jim, I think that 500to700 is to stiff,Im not sure what mine is, I will check it friday its parked at my shop still broke, I have one 12" fox with a bump stop it needs one more shock and I will be good.Im sure there has to be another ttb guy on the board that knows more than me...whats up guys?

[jimyz250]

I just zoomed in on one of the pics I got when I met you, the bottom spring is a 600, top is a diferent brand (color) and cant read that one. I am gettin closer, thanks, and to anyone who knows more!
Jim

[gunit]

I know this is an old thread, but, I am going to build my shock towers/engine cage this weekend, well at least get it started, andI want to get a basic spring rate for my 90 ttb with a standard 4" lift, ext. radious arms, dropdown brackets( they will be replaced by bent beams as money permits), it is really a basic setup, I have 12" swayaway coilovers and will mount the shock basically vertically from either the top of arm or right in front or rear (depnding on space ie master cyclinder/ a/c) and want to be somewhere in the ball park. I read this thread last night and got the impression that 250/275's over 350 would be close, I called autofab and the truck shop today, and both of em said I would need much heavier springs like in the 500 to 700 lb range. I dont want to be way off, I want to be close, and there is a huge gap in rates here. but I kind of have faith in you guys as the info I have gotten on here in the past hasnt steered me wrong yet. I know there are a few of you who have a similar set up. its a standard bronco, with a cage not heavier or lighter than most of yours.. please help...

I use 400/450 on my Bronco. The shocks are 2.5 x 14 Kings.

[jimyz250]

thanks dave, it looks like you have bypasses in your avtar, what do you think of your spring rate, if you caould envision not having the bypasses doing alot of the work? soft, hard? would you change anything? thanks again.

[gunit]

I do have bypasses. I don't think that will affect the spring rate much but you will have to valve your shocks stiffer than my C/O's are. The spring holds the car up and controls ride height. The Shock dampens and controls.

[tnt]

Jim, here is what I have shock overall length 32" top spring is 1200.300.0450 bottom is1400.300.0600s.

[PWmtn]

I am pretty sure Jeremy (Spirit) used 450/450 on my Bronco. Cant see the lable on the top spring due to to much stuff hiding the coil.
I cannot imagins a change for my setup Works great.
Paul

[jimyz250]

thanks! with yours and some other help, I just ordered up a set of 500 over 600's look forward to seein ya out there at the races tnt
JIm

[Blanco]

(depnding on space ie master cyclinder/ a/c)
I had no issues on the A/C side but I did have to remount my Master Cylinder.
http://www.supermotors.net/getfile/189528/fullsize/023_22a.jpg

[jimyz250]

blanco, I would love to see more pics of your shock towers and brake relocation brackets they look interesting, diferent than the others I have seen. I went alittle heavier than most of you guys cause I forgot to tell you all that I have a 15000 winch on the front of the beast, again thanks for all the help. anyone want to send pics of there engine cages, shock towers and braces, I would love to see as many as possible and get as many ideas as possible thanks again.

[Blanco]

http://www.supermotors.net/getfile/218701/fullsize/img_1200.jpg
http://www.supermotors.net/getfile/218702/fullsize/img_1201.jpg

[motrucker]

Old thread, but im curious too see if anyone's finished their setups or testing them and how they like them?

[AngerIssues]

I am pretty sure Jeremy (Spirit) used 450/450 on my Bronco. Cant see the lable on the top spring due to to much stuff hiding the coil.
I cannot imagins a change for my setup Works great.
Paul

Jeremy built that?

One of my very first Baja 500 pre-run stories was with Jeremy, Nancy (before they were married), and J's dad. some crazy stuff.

speaking of "stuff"... they crammed the front of their bronco pre-runner (or was it F-150) into a 4-foot wide ditch on the erindira side. ouch. broke the radius arm in half. shoved a ratchet extension in the tubes and ratcheted it back together. made it santo thomas for margies.. then back into town driving WAY to fast on curvy roads for a busted radius arm.

I was with Coleman... we were pretty.. uh.. flabergasted.

ken

[jimyz250]

I finally got her done! whew, it is workin out great so far, but I am not whoopin on it yet as I havent built the tower crossbar yet, (it'll happen this week) I know I dont have bypasses, but the lower rates the guys at the begining of this thread (sorry for highjacking) seem crazy low, I have ended up with 500/650 as they came in with the wrong rate, I wanted 600 but the 500 is SOFT, I am running 1 turn of preload it is nicly soft as when the 650 kicks init firms up alittle stiff ( I can exchange them for 600's if too stiff) but like I said I havent taken it out yet in real world situations. I can see running 500's or maybe a 450 500 with a bypass. anyway, I got a full 17" of travel out of my 12" sway aways and thats actually limiting the uptravel by 2 " I have some limit straps on order to limit down travel to 15" as I dont like how far it drops, the camber is crasy tucked in. here is a some pics.

[Grimm]

Just reading through this again and we are installing our front coilovers 2.5 kings today. The spring rates they gave us was a 14" 250/ 16" 300. And it will not hold us up to ride height. No one on here mentioned how long each spring was only the rate. Can anyone give me any feedback on the length of their springs. I've got to screw the preload ring??...down like 1.5 - 2 " at full extention to keep tention on the springs, does this sound right??? I like the rates, i just think the springs need to be longer, maybe a tad stiffer.

[Moss2]

Are your shocks 14"? I dont have a set of our springs to look at but Don will probably chime in on what our lengths are. Everything sounds in the ball park, maybe a little light on the lower spring. You will have to run a lot of preload with a light spring and if your truck is heavier than estimated maybe heavier springs. It is unclear from your description why you cant maintain ride height. Did you run the adjusters all the way down the shock body and have no more adjustment? With too stiff of springs you will run into the problem of the springs getting loose at full extension depending of course on where you set ride height in the shock travel.

[Grimm]

Sorry, yes they are 14" shocks. I should also note that they are not charged yet, I'm sure that will make a little bit of a difference. We ran the adjuster (blue thing that screws down from top) about half way down the threads. There was more room to screw it down it just seems that it would be too much. Someone told me that you should have the adjuster within and inch or two from the top? Here is a pic, not sure if it will help. The adjuster is 4" from the top now. At where we would want ride height its about half way through the shock travel, extended about 7".
http://i251.photobucket.com/albums/gg286/Scottdgrimm/DSC02385.jpg

[Moss2]

The pic doesnt look that differnt from what our setting is. I think you are a little softer and shocks mounted a little farther back on the arm which will put you lower. You should have plenty of travel in the springs. I would run it and go from there. Are you going to run another shock?

[Grimm]

We're gonna run a 2.5 bypass to start and eventually go with a 3.0, unless I can find a killer deal on 3.0's. So you think its ok to run the adjuster that far down huh? OK cool. Thanks

[Dave G]

As long as you won't reach coilbind you should be fine with your preload nut.....your crossover nut, however, needs to be moved.

Pressurizing the shocks will make about an inch or two of difference, depending on the pressures you use!

[Grimm]

Crossover nut?.....Is that the two silver ones on the along the threaded body?

[jimyz250]

those spring rates seem awfully light, and from this thread I have found a huge diference in what people run with similar suspension setups, I am running 500/650 with the 500 being a 10" and the 650 a 14" but my shocks are only 12"er's. guess you will have to run yours to see if you like it. my fullsize bronco is Soft with those rates and i am running my shocks about 2 inchs back from the axle. looks like your "crossover nut" needs to be moved quite a bit, those nuts determine when your 2nd rate spring cuts in fully, so if you like the way it rides, but whant the upper half of travel stiffer, you can adjust those down so the stiffer spring comes into play fully , earlier. Have fun, dialing in your suspension is time consuming and expensive if you dont have access to diferent coil rates to try.

[straightaxle]

those spring rates seem awfully light, and from this thread I have found a huge diference in what people run with similar suspension setups, I am running 500/650 with the 500 being a 10" and the 650 a 14" but my shocks are only 12"er's. guess you will have to run yours to see if you like it. my fullsize bronco is Soft with those rates and i am running my shocks about 2 inchs back from the axle. looks like your "crossover nut" needs to be moved quite a bit, those nuts determine when your 2nd rate spring cuts in fully, so if you like the way it rides, but whant the upper half of travel stiffer, you can adjust those down so the stiffer spring comes into play fully , earlier. Have fun, dialing in your suspension is time consuming and expensive if you dont have access to diferent coil rates to try.

The reason the rates seem light is because Grimm's got a straight axle and you have a ttb (based on the avatar photo). Different animals, different EFFECTIVE spring rate. Effective spring rate being what you see at the wheel, based on where the coil over is mounted on the suspension arm. The 500/650 and 200/300 are likely to be similar effective spring rates.

I need to measure the springs we have, but like the other Moss said, the adjustment in the pic is not that different than ours, and yes we do use a little stiffer rate, but we are still a little stiff (never bottoms). Chuck uses soft rates like these. Gas pressure will raise it up a little more like Dave G said. I didn't know what a "cross over nut" until you described it, never knew it was called that!

[jimyz250]

yes totally diferent birds, sorry, and I never knew what the "chrossover nut was called either, until dave g called it that, sounds like as good a name for as any!

[Grimm]

Just an update. The 250/300 just wouldn't hold us up to ride height. So We had King send us a 400 for the bottom and got the shocks charged. This worked out pretty well, and got us to ride height, although it is a little stiffer We'll see how it runs. We may end up going down to a 350 but this is a good place to start testing. The "crossover nut"/ threaded thingymabob, apparently does not come into play with a straight axle set up. Thanks for all the feedback.

[Dave G]

....The "crossover nut"/ threaded thingymabob, apparently does not come into play with a straight axle set up...

Sure it does, the crossover nut dictates where the suspension crosses over from the combined spring rate (using both coils) to the main spring. This does two things - eliminates the possibility of your tender spring reaching coilbind, and increases your spring rate as you near full compression to (hopefully) avoid hard bottoming out of your shocks (or bumps).

With your spring setup, (a 250 tender over a 400 main) your effective spring rate is 153.85 lbs / inch

For this next part, imagine your shock is not charged, and you have zero preload on your springs.

As your suspension compresses with the first 153.85 pounds applied to the shock, your shock shaft has moved 1 inch back into the shock body, and your tender spring has compressed about 2/3 of an inch, while your main has compressed only about 1/3 of an inch. As the next 153 pounds of load is applied to that shock, your shock shaft again slides back into the shock body one inch, and your tender spring compresses another 2/3 of an inch, and your main compresses another 1/3". Somewhere around your 10th inch of travel, you now have about 1538 pounds of force on your shock shaft, and your tender spring has compressed about 6 1/2 inches, but your main has only compressed about 3 1/2. By now your tender spring may be approaching coil bind, depending on the number of turns, the wire diameter, and the working length of the spring.

Obviously, a 4000 lb truck can't have zero preload, so in order to get it to stand up, you'll need to put 1000 pounds of preload on each corner at ride height. If your desired ride height is at 5" (50% travel, and you have 10" of travel), you'll need about 1 1/2" of preload with your shock at full extension. (1000 lbs / 153 lbs/in = 6.5 in.)

Without a crossover nut, you're sitting at mid travel knowing that you have only 5" of travel left which equals only 765 lbs of additional load until you've completely bottomed your shock. If you move your crossover nut so that it contacts the spring slider at 8" of travel, you now have 1259 lbs of additional load capacity. You just gained almost 500 lbs capacity (read that as additional bottoming resistance).

The additional bottoming resistance is far more critical if you are not using position-sensitive shocks (bypass) or air bumps, but even if you are, it could be the difference between a harsh landing that you can drive away from or a metal bending, spine compressing landing that you can't.

DISCLAIMER:

obviously the compression resistance of a shock is not solely dictated by the spring rate, and is greatly affected by the low and hi-speed damping capacity of the shock and the gas pressure used to charge the shock, so don't beat me up for 'splaining it in simplistic terms, I'm just trying to make a point!... that the damn crossover nut CAN come into play if so desired!

[PWmtn]

Sure it does, the crossover nut dictates where the suspension crosses over from the combined spring rate (using both coils) to the main spring. This does two things - eliminates the possibility of your tender spring reaching coilbind, and increases your spring rate as you near full compression to (hopefully) avoid hard bottoming out of your shocks (or bumps).

=============
Dave, Give us some of your incite on coilover crossover for the high to low vs low to high rate on the both solid axles. Right now my latest front setup is at the high rate at static. The rear is set at the low rate with about 1"+ to the transition at static height.
My specs are 2.5" 10"/275# over 14"/400#. (The front has a keeper that is in coil bind except at full droop. Its rate is very low). Rear springs are 16"/250# over 16"/400#. No coil bind at full compression front or rear. Shocks are Fox 150psi res. Truck is a fairly heavy linked EB. Still not as heavy as a full size. Play truck not race and is still a garage queen only highway drives so far. Needs some off road driving before I change it again. Would you change anything?
Thanks, Paul
PS,This one was built by Glen S
PW

[Broncodawg]

Great simplistic writeup Dave! Feel like I died and went to school!:D

[convoy]

My specs, since someone asked.
16/350# over 16/450# on 16" 2.5 SAW

[Clydesdale4x4]

So I typed in "Suspension 101" into the search box, and this thread was burried 4 pages back. It drudged up 11 pages of results... and with the exception of the feller that put TTB looking Radius arms under an 84-5 Toyota, this was the closest to what I am looking for.

I love my truck.

I built, rebuilt it, tweaked it changed it, IT IS MINE!

K, now that is over, I hate the ride, don't mind the travel. More gonna see low speed stuff than fast speed stuff, more concerned about articulation over a rock ( Have a hard time seeing a diesel being an effective desert runner, but If I end up with the Fuller 6 speed OD, as opposed to 6 speed DD I am looking at, top speed will be insane..... :D ), BUT MY MAIN CONCERN is getting the taste of Kidney out of my mouth.

COnvinced I am linking the front, and possibly the rear.

3 or 4 link, have seen both used, is irrelevant at this point. I haven't measured my travel, and need too, But I would say 12-14" maybe more. I can park driver front tire 30" off the ground (steps for a ramp) before I start to lift the rear. Rear about the same, might could gain a little more. Travel is fine for what I do, more is better, but ya know, I am easy.

Spring rate.

Progressive rate coils?

Non Progressive rate coils?

ANd what was this about tender springs and non tender springs, saw tender springs listed on the Poly Performnance website.

The Easy Button would be wheel and Deal my dealer friend out of these particular Fabtech Coilovers and 63" Deavers on a Duramax, that has been reduced to a frame, that has all the IFS parts ruined in an accident. (A Dmax is within 5-10# of my motor, so ratings should be almost dead to the nuts for me) But this Coilovers are 5 years sitting now, and... he wants 12-1500 for them. Web Shopping on the Poly Site, I can be set up in the front for less, still needing to make links, hoops etc....

So lets start right from the git go... I played with the calculators in the link a bit, and came up with 390# rate, and I was thinking I needed to be close to 400.

Motor weighs 900#, changing to 1200 btw, its a 0ne ton 4 door beast, scales at 6500~

1500#~ is unsprung, Dana60/70 37" tires on Steel wheels... etc.

WHere do I look?

so after I re park my truck on my RTI ramp (tree out back), what measures travel? distance one side moves minus the distance the other side moves?

Help.....

I am leaning towards Bilstein 9100 Coilover's (rockkrawler series is the their label) Fox looked good, and one other I was looking at. But for the Price, the 9100's seemed to be a valid deal.

ANy leaf spring advocates want to chime in, that input is welcome as well, hell that WOULD be the easy button.... already leaf x 4 corners.

Current lift, is a shackle flip in the arse, using the front rear spring hanger for the rear rear spring hanger, gave me 6-7".. and (Rancho Branded I am assuming) 4" leafs in the front.

Current travel...

https://lh4.googleusercontent.com/_UnyULVO3Xr8/TLOd-eYvSTI/AAAAAAAAB9o/VgTH1nKj-Ec/s640/IMG_0216.JPG

https://lh6.googleusercontent.com/_UnyULVO3Xr8/TLOeDZwBSbI/AAAAAAAAB9w/QD5kgyI1NoE/s640/IMG_0218.JPG

There's more, but for a big dumb beast, he has okay travel, IMHO.