custom coil springs

[socalmoto]

i have a project truck and need long heavy coils for a 2.5c/o. we currently have a 6x500 over a 19.5x800 and the rate is too soft. we have 1/2" preload on the 800s at full shock extension (meaning short spring is doing nothing) not giving enough travel. I've tried hyper coil and its $430ea to make a custom spring. I've heard eibach doesn't really like to make custom coils,

so any where else to check before dumping $900 into a pair of coils?


and i realize the coils will buckle, so I'm going to make a slider on the shock to help with that. no room for a 3.75id spring.

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[racer56]

Consider changing your motion ratio.

[socalmoto]

Consider changing your motion ratio.

That may be the only fix for it, but its driving right now and id like to give the long springs a shot. We really want to keep the travel numbers we have and moving the shock mounts outward would lower the travel by 3-5".

[Johnny7903]

You might give PAC a shout, they may be able to do it for cheaper. http://www.racingsprings.com/

[cosmo]

Try Mirage, they may have what you want .

[partybarge_pilot]

Do you have enough room to step up to a 3.0 spring? Those are easier to get and spacers are easy to make.........

[socalmoto]

Ill give pac and mirage a shot.

and pb, do you mean a 3.0id spring? or a 3.0c/o spring (3/75id)? I am trying to find a 3.0id spring, but the 3.75 wont fit.

I sent an email to midwest spring and im hoping they have something like what i need. I saw some part numbers for a few springs made by them and if the numbers mean what i think they mean, then they should have them.

[Chris_Wilson]

If you cut a coil in half you double it's rate. So you could get a 12x500 and make it into a 6x1000 for example. Or make an even stiffer coil by cutting down an 18x500 to 6". then if you stack that onto the 19.5x800 the effective rate will still be less than 800 but probalby close to what you are looking for.

[Kritter]

i have a project truck and need long heavy coils for a 2.5c/o. we currently have a 6x500 over a 19.5x800 and the rate is too soft. we have 1/2" preload on the 800s at full shock extension (meaning short spring is doing nothing) not giving enough travel. I've tried hyper coil and its $430ea to make a custom spring. I've heard eibach doesn't really like to make custom coils,

so any where else to check before dumping $900 into a pair of coils?


and i realize the coils will buckle, so I'm going to make a slider on the shock to help with that. no room for a 3.75id spring.

What is the application?

Your information supplied as ambiguous. If the bottom 800lb/in spring is preloaded .5" then the top 500lb/in spring is preloaded .8" for a total of 1.3" of preload or 400lb of preload.

How much are the coils compressed at ride height? Does the truck sit where you want it? Where does the rate cross over to single rate or are you just coilbinding the top coil?

How much stroke does the shock use on the truck? (full droop limitng the truck more then full extension of the shock and metal to metal on the truck being less them bump cap to rod end hitting. IE a 14" stroke coilover doesnt stroke 14" on most vehicles when set up right)

how much travel does your top and bottom coil have? Call the MFG if you dont know and dont settle for a "about half the free length" answer.

[socalmoto]

Midwest spring said no, so back to square one.

If you cut a coil in half you double it's rate. So you could get a 12x500 and make it into a 6x1000 for example. Or make an even stiffer coil by cutting down an 18x500 to 6". then if you stack that onto the 19.5x800 the effective rate will still be less than 800 but probalby close to what you are looking for.

that may be an option, but will i run into issues with it not being closed wound? I can grind the end flat, but without the last closed coil it might be unstable seating.

What is the application?

Duramax with 18.5" of travel

Your information supplied as ambiguous. If the bottom 800lb/in spring is preloaded .5" then the top 500lb/in spring is preloaded .8" for a total of 1.3" of preload or 400lb of preload.

I didnt write down the preload numbers as i didnt think there would be this much issue so all the numbers are guesses. The truck left the shop with 1-1.5" preload on the top coil and i thought it had enough spring travel. I STILL have never seen a chart with spring travel for the 6x500 so i just measured the gaps between the coils. The truck came back for some more parts 2 weeks later and they adjusted the coil preload because the ride height settled down too low. The top coil was preloaded around 2.25-2.75" and the dual stops were preloaded 1/2" down on the 800s at full shock extension. He defintely coil binded (I measured he coil binded 2" before the shock bottomed out) and i told him no more offroading till we get the springs figured out. With the 800s being under preload i just pulled the top coil thinking i could find a longer main spring somewhat easily and i didnt want to have to hammer the dual sliders up and down if the top coil wasnt doing anything.

How much are the coils compressed at ride height? Does the truck sit where you want it? Where does the rate cross over to single rate or are you just coilbinding the top coil?

With 1/2" preload on just the 800 at full extension it still sits a little low. Maybe 1-1.5" wheel travel too low. I can get a meaurement on how much the spring is compressed tonight or tomorrow. but i think i estimated the sprung weight up around 1700lbs on each front corner.

[QUOTE=Kritter;1436400]How much stroke does the shock use on the truck? (full droop limitng the truck more then full extension of the shock and metal to metal on the truck being less them bump cap to rod end hitting. IE a 14" stroke coilover doesnt stroke 14" on most vehicles when set up right)

Truck is bumped and strapped at 19.5" measured from the hub face. Shock travel is 9.5" on a 10" shock. It was 9.25" when it left but the straps have stretched a little so the shocks are very close to full extension at droop now.

how much travel does your top and bottom coil have? Call the MFG if you dont know and dont settle for a "about half the free length" answer.

Ive asked and looked for the 6x500 spring travel MANY times but never come up with anything. I just keep getting sent the eibach spring catalog. The catalog does have travel for the 4x500, but doesnt show 6x500 or the 19.5x800. I did measure the gaps on them at one point a while ago for another project, but dont know where i wrote it down. I usually just measure the gaps to be sure. When this duramax came back with the new preload im pretty sure it wasnt going to have enough spring travel and high enough ride which is why i pulled the top coil. WE needed another 2+" of spring travel and the top coil wasnt close, but its been a VERY busy couple months and ive got way too many other things taking up brain memory....so i may need to re measure