rusty's lift

KJ04 · **Posted:** Sun Jun 01, 2008 8:35 am

kj924 wrote:

Spring rate has nothing to do with lift......period!!!! We already sloved that argument by measuring the coils last night. The lenght of the coil is what gives you lift, spring rate will tell you how much a spring will compress.
Derick

I'm sorry but, I have to differ with your theory on the spring weight.
If you take 2 springs of identical lenght and one is a 300 lb. rate and the other is a 400 lb. rate, the 400 lb. rate spring will simply not compress as much under the weight of the vehecle, there by, creating more lift height. Does this make any sence now?

ATXKJ · **Posted:** Sun Jun 01, 2008 9:29 am

The spring length providing lift - presumes that there is no weight on the spring while the Jeep is sitting - that is not true, it is under pressure, it is supporting weight.

Point of comparisons - all OME springs for Liberty's are the same length, with different spring rates - when the CRD 1st came out - people tried to use the OME 927's at 400 lbs/in - and got virtually no lift - the CRD was too heavy for the spring, OME later came out with the 790 - at 500 lbs/inch - same free length and it provide the lift for CRD's. The free length was the same, the rate was different the resultant lift was different.

My lift dropped almost an inch when I installed the ARB, spring length was the same - but the force on the spring changed.

Vendors normally measure lift at the spring length ~1 1/4" for OME - however the strut assembly contacts the lower A arm about mid length - so the vehicle lift - is actually the ratio of the length of the A arm pivot to the end of the A arm divided by the length of the A arm pivot to the strut mount - That's the leverage the A arm has - and it's about 2 - so a 1 1/4" spring - normally nets about a 2 1/2" lift - depending on the weight on the front.

Also - Daystar's work pretty well - again when CRD's first came out - there were no spring suspensions that worked - We used Daystar spacers - and mine have made 2 trips to Moab no problems - I will at some point upgrade to the OME to get the 500 lb spring rate so I can add a winch- but it's not a rush.

501 · **Posted:** Sun Jun 01, 2008 9:32 am

KJ04 wrote:

I'm sorry but, I have to differ with your theory on the spring weight.
If you take 2 springs of identical lenght and one is a 300 lb. rate and the other is a 400 lb. rate, the 400 lb. rate spring will simply not compress as much under the weight of the vehecle, there by, creating more lift height. Does this make any sence now?

This makes sense to me.

If you take a KJ weighing say 4500 lbs and put it on 3 different sets of OME springs (lets say Lt Duty 300 lb. rate, Med. Duty 400 lb. rate, and Hvy Duty 500 lb. rate) all three measure 15 1/2" when sitting side by side off the KJ. Now put them on the KJ and lower it. The Lt. Duty will compress down from the weight of the KJ to say 13", the Med. Duty will compress down to 14" and the Hvy. Duty will compress down to 15". Therefore resulting into different lift heights from 3 different springs that started out the same length but have different load ratings.

At least thats what I got out of all of this

(Note: the ratings and measurements show are for informational purposes only, I am not a mechanic and am using the numbers for an example only, not saying these are actually results.)

KJ04 · **Posted:** Sun Jun 01, 2008 10:01 am

501 wrote:

KJ04 wrote:

I'm sorry but, I have to differ with your theory on the spring weight.
If you take 2 springs of identical lenght and one is a 300 lb. rate and the other is a 400 lb. rate, the 400 lb. rate spring will simply not compress as much under the weight of the vehecle, there by, creating more lift height. Does this make any sence now?

This makes sense to me.

If you take a KJ weighing say 4500 lbs and put it on 3 different sets of OME springs (lets say Lt Duty 300 lb. rate, Med. Duty 400 lb. rate, and Hvy Duty 500 lb. rate) all three measure 15 1/2" when sitting side by side off the KJ. Now put them on the KJ and lower it. The Lt. Duty will compress down from the weight of the KJ to say 13", the Med. Duty will compress down to 14" and the Hvy. Duty will compress down to 15". Therefore resulting into different lift heights from 3 different springs that started out the same length but have different load ratings.

At least thats what I got out of all of this

(Note: the ratings and measurements show are for informational purposes only, I am not a mechanic and am using the numbers for an example only, not saying these are actually results.)

Exactly

Most everyone here seems to be able to grasp this concept except for KJ924.

kj924 · **Joined:** Wed Jan 16, 2008 11:01 pm **Posts:** 103

Ok, this is the last post I will make on this ridiculous subject.

Lets define "lift". IMO lift is anything over stock height. If an OME coil was 14" same as the stock one removed from my truck, and this 14" coil had a 500lb spring rate, then the KJ would sit at stock height BUT WOULD NOT SAG OR SIT ANY HIGHER THAN STOCK. Think about it, you need more coils to achieve "lift".

Here's something else to think about: I replace my original springs with new Mopar springs of the same rate and height, and the truck sits higher, did I lift the truck or just take it back to original height?
Thats my point right there...you don't gain lift by using heavier rated springs, just produced less sag when suspension is loaded.
Less sag does not equal lift.

KJ04 · **Posted:** Sun Jun 01, 2008 11:11 am

kj924 wrote:

Ok, this is the last post I will make on this ridiculous subject.

Lets define "lift". IMO lift is anything over stock height. If an OME coil was 14" same as the stock one removed from my truck, and this 14" coil had a 500lb spring rate, then the KJ would sit at stock height BUT WOULD NOT SAG OR SIT ANY HIGHER THAN STOCK. Think about it, you need more coils to achieve "lift".

Here's something else to think about: I replace my original springs with new Mopar springs of the same rate and height, and the truck sits higher, did I lift the truck or just take it back to original height?
Thats my point right there...you don't gain lift by using heavier rated springs, just produced less sag when suspension is loaded.
Less sag does not equal lift.

Quote:

Poor him??? Poor me you mean. I just came on here an gave my opinion on my Rusty kit, which was the point of kjsport05's question. Then I got jumped by several people who think they are right, and in their own little world they are right. But what got me was the fact someone stated that spring rate will net you lift.Spring rate is the measure of spring deflection when a given weight is applied to the spring.

Spring rate has nothing to do with lift......period!!!! We already sloved that argument by measuring the coils last night. The lenght of the coil is what gives you lift, spring rate will tell you how much a spring will compress.

I thought this was a good place, until I was called slow and dense. If this is the way your forum runs, by demeaning people's intelligence, then there's no place for me here.

Thanks to all the good people I have talked to on here, I hope the
ignorance and thick headedness of some won't drive away future members.

May as well end it here, as you seem to be blinded by the light of some of us ignorant and thick headed people. Maybe there are just to many trees in the way to prevent you from seeing the FOREST. :roll:

Inc · **Posted:** Sun Jun 01, 2008 11:31 am

KJ294, in all seriousness, I apologize if I have offended you. It just seems like you really don't understand what some people on here are saying. Yes if you have two 500 lbs. springs and one is 10" tall and the other is 15" you would get 5" of lift, but if you put one 10" spring at 200 lbs. and a 10" spring at 500 lbs on the same exact kj. the 500 lbs. will sit higher, is that lift, YES.

See, the stock springs could never have sat as high as the OME, even if they were the same length from the beginning because they are a softer spring and thus would sit lower from the start. So adding the OME would give you "lift", meaning hold the jeep up higher, over the stock height. The springs may not be a gain of height when off the KJ, but all that matters is how they sit once on the jeep. :wink:

So by your own definition, "lift is anything over stock height" OME do give you some lift. It may not be a ton of difference, but it does make the kj sit higher and that is some of the lift we are trying to tell you the OME gives because of spring rate.

tommudd · **Posted:** Sun Jun 01, 2008 11:39 am

Some people get it some don't . This is a done topic to me. Nothing you can say will change his mind and us that have been trying to explain to him are tired of explianing. I guess years of experience will never mean anything to some.

Tom

jason thompson · **Posted:** Sun Jun 01, 2008 11:40 am

Guys he will not EVER get it
not that he can not but rather he does not want to
he does not under stand that some thing that was made to hold 300# will sink more under the same load when compared to something that was made to hold 400# ,NO ONE can be this simple

Inc · **Posted:** Sun Jun 01, 2008 1:17 pm

So kj924 is leaving us:
http://www.lostjeeps.com/forum/phpBB3/vie ... hp?t=32943

ATXKJ · **Posted:** Sun Jun 01, 2008 3:31 pm

501 wrote:

This makes sense to me.

If you take a KJ weighing say 4500 lbs and put it on 3 different sets of OME springs (lets say Lt Duty 300 lb. rate, Med. Duty 400 lb. rate, and Hvy Duty 500 lb. rate) all three measure 15 1/2" when sitting side by side off the KJ. Now put them on the KJ and lower it. The Lt. Duty will compress down from the weight of the KJ to say 13", the Med. Duty will compress down to 14" and the Hvy. Duty will compress down to 15". Therefore resulting into different lift heights from 3 different springs that started out the same length but have different load ratings.

At least thats what I got out of all of this

(Note: the ratings and measurements show are for informational purposes only, I am not a mechanic and am using the numbers for an example only, not saying these are actually results.)

for your example you don't have to be a mechanic - it's just simple math
a 300 lb/in spring would be compressed from 15 1/2 to 13 inches by 750 lbs of pressure - 300 lbs/in * 2 1/2 inches
a 400 lb/in spring would be compressed from 15 1/2 to 14 inches by 600 lbs of pressure - 400 lbs/in * 1 1/2 inches
and the 500 lb/in spring would be compressed from 15 1/2 to 15 inches by 250 lbs of pressure - 500 * 1/2 inch

so a better comparison would be to use the same weight - say the 600 lbs of pressure

the 300 lb/in spring would go from 15 1/2 to 13 1/2 = 2 inches of compression to support the 600 lbs
the 400 lb/in spring would go from 15 1/2 to 14 = 1 1/2 inch of compression to support 600 lbs
and the 500 lb/in spring would go from 15 1/2 to 14.3 inches to support the 600 lbs (600/500 = 1.2 in)
so in this example - with constant 15 1/2 inch free length springs - the lift of the springs would vary by .8 inches and due to the leverage of the lower A arm would make about 1.6 inches of difference in ride height.

Fulltimer · **Posted:** Sun Jun 01, 2008 4:08 pm

ATXKJ

If I ever need something figured out using numbers...........I"M GONNA CALL YOU! :lol:

Terry

kjsport05 · **Posted:** Sun Jun 01, 2008 8:45 pm

http://www.rocky-road.com/kjome.html

so if i get the ome medium setup, is this all i need?

SoDakJeep · **Posted:** Sun Jun 01, 2008 9:33 pm

correct 4 springs and 4 shocks but get them from Heather at AllJ's www.boulderbars.com

jsc7002 · **Posted:** Sun Jun 01, 2008 11:44 pm

kjsport05 wrote:

http://www.rocky-road.com/kjome.html

so if i get the ome medium setup, is this all i need?

yep or you can go with the HDs :wink:

, and Dirk over at DPG Off-Road sells them too

www.dpgoffroad.com

Dje Ryu · **Posted:** Sun Jun 01, 2008 11:51 pm

Just stay away from RRO. They suck!

jsc7002 · **Posted:** Mon Jun 02, 2008 12:01 am

Dje Ryu wrote:

Just stay away from RRO. They suck!

lol thats true too, but kinda sad b/c that limits places to get parts for the KJ

rusty's lift

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