A few quick questions about coil spacers.

1. With a 1" spacer inside the strut assembly - how much lift will that give?

2. With a 1" spacer on top of the strut assembly - how much lift will that give?

I am pretty sure that with the outside spacers you almost get a 2 to 1 ratio or something close to that. I have been known to be wrong before. I am unsure of the spacers that go inside the coil pack though.
Anyone care to share some facts and knowledge about these things?
I have searched and still some things aren't very clear.


TIA

Oh yeah.....This is with stock struts and coils from a 98 4cyl non-trd. I do have a set of 98 v6 coils too. No aftermarket stuff for me........

 

It doesn't matter whether they are inside the pack or not. Both will give the same amount of lift.

 

1.5" spacer gives 2.5" of lift.

 

If you make a spacer to fit on top of the stock coil plate, it will yield twice the lift. (1" spacer = 2" lift.)

If you make a spacer that replaces the stock coil plate, they usually yield the amount of lift the spacer is. (1" spacer = 1" lift) Now, keep in mind it all matters on where you place the shock mount on the bottom of the spacer! To far down and the shock will jam together on bottoming. To high and you won't get the lift you want.

From making many different kinds of spacers for my own truck, I find that making one to go on top of the top plate the easiest but replacing the stock plate is a better design. If you replace the top plate, make the shock mount anywhere from 3/8" to 1/2" higher than the bottom of the spacer. This will keep the shock from jammin' on bottoming. If you don't follow me, it will become apparent when you go to test fittin' your spacers.

Good luck and Happy Fabin'

 

Thanks all for the responses.

SloPoke - I take it from the way you are creating your spacers that you are combining both spacers into one by varying where the actual center mount for the strut is? Like you are getting some preload of the spring for lift and getting extra lift from the "thicker" top plate too? Do I understand you correctly?

Bamachem - Is that a cornfed spacer you are talking about? I have seen your posts on the thread about the different coil springs. There is a lot of info in that thread! I would love to be able to build the franks but I can't afford to. I am trying to figure out how replicate that setup with stock struts and coils by making a combination of preload and topout spacers to get the stock strut the "same length" as a bil or ome and still keep it soft and flexy with minimal preload. I wonder is it possible with the stock struts and coils with custom spacers? I only want 2 inches of lift - I don't wheel that much. I still want it to ride good also. Am I wasting my time or can it be done?

Thanks.

 

Hey, 88!
In reference to your sig, try Old State Rd. or near the Saluda River for wheelin'. There also might be some places up near the Newberry/Prosperity side of Lk. Murray for wheelin, too.

 

Warning thread Hijack - WIth the change in Cornfed spacer material of construction, what is the favoured spacer currently available?

(for bonus points, PM me with where you are obtaining your inland truck upper arms from - google got me nowhere)

 

Then why is the cornbred spacer about 1.25" thick and yields 2" of lift? This type of spacer fits inside the pack.

 

88toy4x4: Yes, you seem to be understanding perfectly.

Robinhood: Here's a scenerio for getting 2" lift from a 1 1/4" spacer.
Top surface of spacer is 3/4" above the top surface of the stock top plate. (this yields double lift = 1 1/2" lift)
Bottom surface of the spacer is .5" below the bottom surface of the top plate. (this yields same lift = 1/2" lift)
for a total of 2" of lift
(of course, the top plate is replaced by the spacer and these dimensional referances are just for mental picturing)

Again, When making spacers that replace the top plate you have to be carefull that the design does not allow the shock to be stuffed/jammed together during bottoming. As you change one dimension in this design, all the others change with it.

It is easiest just to make a spacer that fits on top of the stock top plate. This keeps the stock preload and allows the stock amount of travel. When doing it this way, you also need to drop your bump stops to keep from jammin'/stuffin' the shock when bottoming. If you do loxer your bump stops, it's not really nessasary to lower the amount of lift. Stock, the shock have about 1/2" more travel to bottom when the truck on it's bump stops. This can be all but subtraceted (keep 1/8" for safety sake) from the lowering bump stop dimension and get you just a little more travel. (so if you lift 2" this way, you can lower your stops 1 5/8" and still be 1/8" away from jammin'/stuffin' the shock at full compression.


Edited and it's still sounds confusing when I reread it. :pat: If anything isn't clear, holla!

 

Edited out picture.

As for preload, see my website:
http://www.robinhood4x4.com/suspension2.htm
I've asked real suspension engineers (they design suspensions for a living) on an engineering forum to proof read it and they find nothing wrong with it and agree that spacers and preload are a myth.

You can also read this about preload:
http://www.tundrasolutions.com/forum...59&postcount=4

 

Hmmmm

My Cornfeds replaced the Top plate, bolts and everything. ???

are those possibly Rear coil spring spacers you have there Robinhood ?

 

Nice write ups but I don't see where it takes in to account the shock being at it's max length then installg a spacer. The digram just shows the spacer added to the length of the shock. When the shock is at it's maxed length and you move the upper coil seat down, whilst the bottom of the coil remains the same, it preloads the coil. That's not saying that it'll will compress different as per your other diagram, (500lbs = 15") that doesn't change. The thing that changes is the amount the spring compresses. If you move the seat down 1" yopu now have a 19 extended lenght, and then load it with 500lbs it will compress to 15. But this time it moved 4" not 5". The 1" is preloaded.

 

David made a few different models of spacers. I'm not a cornfed offering guru but I believe he offered Gen1 and Gen2 spacers. One replaced the top plate and the other fit between or on top. I'm not sure. I think in between.

and I'll agree, they look like rear spacers but they'd have to be 7" diameter not 5" like they look in the pic. 5" dia. would be a front spacer.

 

Yes, I agree when the shock is fully extended and a spacer is used, the preload is increased. However, we don't care what the preload is when the tire is in the air. We only care about the static length of the shock/spring when the weight of the truck is on the spring. I'll get into the reasoning behind this next.

This is the reason most people think the preload is increased, when the shock is removed from the truck, naturally you have to compress the spring to install the spacer. But that is not the condition in which the shock is in when the weight of the truck is on the spring.

You're saying that at a spring rate of 100lbs/in and a compression of 4" plus the "preload" of 1" =500lbs---> 4"x100lbs/in + 1"x100lbs/in =500lbs.

The problem with this is that the shock is free to extend 1" when the weight of the truck is on the shock. The shock length is not limited like it is when fully extended. Since the shock can extend 1" the preload is alleviated. So---> 5"x100lbs/in=500lbs

This is the reason we don't care about the condition of a fully extended shock.

 

I may have been premature about using that picture. I take it back.

 

I agree that the preload is eleviated from the weight of the truck but that same eleviated preload is what supplies the lift. (by being eleviated) This is exactly what I was trying to say but, with you help, this sounds like and easier way to explain it. When making a spacer, you need to calculate in the preload on the extended assembly as it turns in to lift when eleviated by the weight of the truck. That added with the lift calculated from moving the top surface = total lift the spacer will yield.

When you start moving the shock mounting surface along with the altering the amount the spacer sticks below the stock plate, it really gets a little more technical in calculating total lift in relation to the top surface. Most the time, it was easier just to buld and test rather than calculate. Although, after a couple sets, it became fun to calculate and see how close to actual I was.

 

Hmmm...it sounds like we're saying the same thing but going about it a different way, hehe.

Would you care to go into the calculations? Math is a universal language...

 

whats the name of that fourm?

 

You mean tundrasolutions?

 

the engineering fourm that you referred to