OME spring mix and match

[msggunny]

Looking at putting in some OME springs on the D2. Im running a 9.5ti winch in a tactical rover bumper (full bush guard). Im thinking the XHD for the front because of the weight, or will this be too much spring and i should use an HD instead?

I dont want to run XHD or HD in the rear, i rarely carry much stuff in the back and am worried that too stiff a spring will make the ride horrible. Dont really know though as i have never ridden in a truck with XHD springs.

Will mixing XHD and Med springs be an issue?

Can I use HD instead of XHD, or do i have too much weight in the front?

Thanks,

 

[Buddy]

It depends. I don't think the TR bumper or the 9.5ti are super heavy compared to something like a RTE with a 10k Husky. Also if you're running synth rope that will save a bit of weight. I would think that's probably pretty normal for a bumper winch combo and no XHD.

But if you mix and match too much you might end up with a bit of Carolina Squat going on. You should probably think about the kind of lift you want to end up with and then pick your springs based on that.

For some reason with Rovers they decided that to increase the lift they take the same height spring and just make it stiffer rather than longer. This does help though because these trucks get a bit sketchy off road when you lift them too much and the HD springs help to mask that.

When I had a normal lift on my DI I was very happy with the RTE HD Front and MD rear springs.

 

[Tugela]

But if you mix and match too much you might end up with a bit of Carolina Squat going on.

What is that? Is it something like the "always going uphill even on level ground" look that I see on nearly every Toyota 4Runner and pickup made prior to 2003 that have never had rear springs replaced?

 

[K-rover]

What is that? Is it something like the "always going uphill even on level ground" look that I see on nearly every Toyota 4Runner and pickup made prior to 2003 that have never had rear springs replaced?

Its worse than that.. Kids think that only lifting the front and dragging the ass like a dog is cool. They usually have 22 or 24" wheels with stretched out tires... :rofl::banghead:

 

[K-rover]

I used to run 761 and 763 OME springs.. Advertised as a 3" lift, but I netted 2.5 at best. I have a TR front bumper and Tigershark 9500 with steel wire. The front was good, but the rear was too stiff. I didnt carry enought weight on the rear so it was stiff and bouncy. I believe both those were HD, not sure about XHD?

 

[p m]

I used to run 761 and 763 OME springs.. Advertised as a 3" lift, but I netted 2.5 at best. I have a TR front bumper and Tigershark 9500 with steel wire. The front was good, but the rear was too stiff. I didnt carry enought weight on the rear so it was stiff and bouncy. I believe both those were HD, not sure about XHD?

761 is a front medium-duty spring, 763 - extra heavy duty rear. The specs at EE website confirm your observations.
These springs on a D2 may offer reasonably close ride height front and rear, but this combination should be horrendous dynamically.

 

[msggunny]

Anyone running OME 2781's or have had experience with them? EE's website has them listed as Heavy/Medium. Im not really sure what they mean, unless its that they run like a medium until they are loaded?

 

[p m]

You know, you could actually do things right - measure the current stance of your truck and take it to scales so you know the weights on the front and rear axles. After that, choosing the springs becomes a pretty simple math exercise:
(a) divide the weight on the front axle by two
(b) for all springs on the market, the height under load would equal (uncompressed length) - (spring rate X half the weight on the front axle) - INCORRECT
(b) for all springs on the market, the height under load would equal (uncompressed length) - (half the weight on the front axle / spring rate)
(c) pick the ones with the loaded height that you want; there could be more than one, in which case you decide if/how you want trade handling for ride quality
(d) downselect the choices of the front springs to one kind;
(e) calculate the spring rate for rear axle as (spring rate for front springs) x (weight on the rear axle / weight on the front axle)
(f) repeat steps (b) and (c) for rear springs.

Does it sound like overthinking the problem?
It might, because it certainly is - there are very few spring/shock combos that have not been tested yet.

 

[SGaynor]

Just go with the HD springs front and rear and be done with it. I got about 2" of lift (HLC front bumper, GD bumper rear, HLC sliders), and didn't really notice that big of a difference between the springs and my rear air bags (that I replaced with springs). I got mine from Justin.


I also added the OME nitro shocks at the same time.

 

[CORover]

You know, you could actually do things right - measure the current stance of your truck and take it to scales so you know the weights on the front and rear axles. After that, choosing the springs becomes a pretty simple math exercise:
(a) divide the weight on the front axle by two
(b) for all springs on the market, the height under load would equal (uncompressed length) - (spring rate X half the weight on the front axle)
(c) pick the ones with the loaded height that you want; there could be more than one, in which case you decide if/how you want trade handling for ride quality
(d) downselect the choices of the front springs to one kind;
(e) calculate the spring rate for rear axle as (spring rate for front springs) x (weight on the rear axle / weight on the front axle)
(f) repeat steps (b) and (c) for rear springs.

Does it sound like overthinking the problem?



It might, because it certainly is - there are very few spring/shock combos that have not been tested yet.

Have you seen the T-shirts that say "I didn't use math today"? I am going for the I did use math today...


So let's use 5000 as a vehicle weight (YMMV) and 3000 for the front and 2000 for the rear.
a. 3000/2=1500
b. This is where I get lost. Uncompressed length (use 17.2) minus spring rate x half front axle weight so, 150 lbs/in x 1500. You get 17.2 - 225000. That does not work
skip c and d
e 150 lbs/in x 2000/3000 or 150 x 0.666667 or 100
f?


I used some info from the red90.ca sight that has some old Rover spring info on it just for the numbers.


Can you straighten this out for me?

 

[p m]

Got me brother. Here's a corrected version:

(b) <...> the height under load would equal (uncompressed length) - (half the weight on the front axle / spring rate)

In your example - height under load = 17.5 - (3000/2)/150 = 7.5 in

I was thinking of something different when I wrote it.

 

[Buddy]

Got me brother. Here's a corrected version:

(b) <...> the height under load would equal (uncompressed length) - (half the weight on the front axle / spring rate)

In your example - height under load = 17.5 - (3000/2)/150 = 7.5 in

I was thinking of something different when I wrote it.

Yes, but if he's got 3,000 lbs of sprung weight on one axle he needs to be looking at XXHD springs.

 

[p m]

Yes, but if he's got 3,000 lbs of sprung weight on one axle he needs to be looking at XXHD springs.

Not necessarily.
OME (2)762 springs are about 16.5" unladen and have spring rate of 300-340 lb/inch. Loaded spring length is going to be about 11.5" - pretty far from fully compressed.

By the way, here's a nice list of Land Rover coil springs.

 

[CORover]

That's 3000 per axle, not per corner.


That info is just a copy of the red90.ca info I used in the example. They just copied it, it mentions red90.ca in the heading at the top of the list.

 

[Buddy]

Not necessarily.
OME (2)762 springs are about 16.5" unladen and have spring rate of 300-340 lb/inch. Loaded spring length is going to be about 11.5" - pretty far from fully compressed.

By the way, here's a nice list of Land Rover coil springs.

Not sure if those are front or rear springs. I assume rear based on the spring rate. So if it's a rear spring 11.5 is about factory ride height. My RTE MD 3" springs with a well kitted truck HD bumper, gas tank skid, tools and gear sat at about 14.5-15". So yeah 3,000 lbs sprung is a heavy bitch.

 

[Buddy]

That's 3000 per axle, not per corner.


That info is just a copy of the red90.ca info I used in the example. They just copied it, it mentions red90.ca in the heading at the top of the list.

Ok if you have 3,000 sprung weight per axle. that's 6,000 sprung weight and probably 2,000 lbs of unsprung weight. So you have a disco that weighs 8,000 lbs. God lord....

 

[Buddy]

You're best option is to actually weigh the truck. But if you think about it this way. Let's say you have a 5,500 lb truck. Depending on tire size you probably 250-400 lbs for tires, another 1,000 lbs (which is light) for axles etc. radius arms, a-arm, trailing links, springs and socks are kind of middle ground between sprung and unsprung so let's say another 200 lbs there. So now we have 3,800-4,000 of sprung weight. So let's say a 55/45 split front to rear. So you have roughly 1,800-2,000 sprung weight per axle. Add passengers and gear and you're probably at 2,000-2,200 per axle.

 

[p m]

Ok if you have 3,000 sprung weight per axle. that's 6,000 sprung weight and probably 2,000 lbs of unsprung weight. So you have a disco that weighs 8,000 lbs. God lord....

Do you know the definition of unsprung weight? It is, essentially, the weight of axles and tires. I don't think I have ever had more than 110lb/tire, and the axles are about 300 apiece, give or take. Not sure where 2000 lbs come from.

And, obviously, if the truck dents the scales at 6000 lbs, unsprung weight is counted in - so you'd have to use something like 5k lbs to calculate spring heights.

CORover's response to you was that 3000lbs referred to total weight on a single axle, not weight on each side of an axle.

 

[Buddy]

Do you know the definition of unsprung weight? It is, essentially, the weight of axles and tires. I don't think I have ever had more than 110lb/tire, and the axles are about 300 apiece, give or take. Not sure where 2000 lbs come from.

Yes I do, and technically it will also include a portion of the weight of the suspension links etc. 2,000 lbs was just a random number which is about as accurate as 3,000 lbs for sprung weight.

And, obviously, if the truck dents the scales at 6000 lbs, unsprung weight is counted in - so you'd have to use something like 5k lbs to calculate spring heights.

I guess you're trucks are a lot heavier than any I've owned. Based on rough math my current truck is about 1,300-1,400 lbs of sprung weight in the rear (220lb coils compressed 3ish inches) and 1,500-1,600 in the front. (86lb spring rate compressed 8-9 inches). The heaviest I can remember doing the math on was around 2,200-2,300 front and 2,000-2,100 in the rear.

 

[p m]

Your post a few minutes after the one I responded to clarified things a bit.

I don't know how heavy are everyone's trucks; I don't think mine would hit 5k on the scales. Whenever I get it started, I'll take it to the city dump just to hit the scales, out of curiosity.