wheelbase loss with lift

how much wheelbase loss did you guys loose with a 4.5-5" lift. i know the front can be remedied by longer control arms when installing the lift. but the rear springs are what i am talking about. with a 23" eye to center pin on the leaf, i measured a 3/4" loss when the leaf is dropped 5". so in a sense a 23 3/4 eye to center pin leaf would be nessesary to keep the wheel/tire in the same location of the wheel well. i am toying with a few differant (stock vehicle) spring packs with different eye to center pin locations. i would like to end up with a 4.5-5" lift but also have the rear wheels set back 1" when done.

what i came up with is using a stock blazer leaf pack. (52" total length, 26" eye to center pin) using u-bolt eliminators that have an offset center hole of 1.5" should net me the desired wheel/tire location. actually from my measurements it will end up being 3/4" further back than stock with a 5" lift.

the more arched the leaf springs the more towards the rear the axle will go when the suspension compresses. if you move it too far back you will find that you may rub the rear of the wheel openings on suspension compression.

i run ruffstuff antiwrap leaf perches with 3 centering holes to fine tune my wheelbase.

thats just it, stock blazer leafs have less arch, but are thicker leafs. i believe they are rated at 1700#. which would work great for the amount of weight i plan to add. being they do not have much arch they should have less forward back movement during the suspension cycle, and more just up and down. XJ have alot more fender well area that can be removed from the rear than the front, so interference is no problem.

are you saying stock blazer leafs have less arch than stock xj leaves?

i find that hard to believe seeing that blazers are a spring under axle configuration.

i have also heard that blazer zr2 leaves are a direct bolt in for xjs and give 3.5" of lift. but dont quote me on that

no, i am not.
actually i am talking about early full size blazers. (late 60s-70s) unsprung and laying on the ground, they have about the same arch ( slightly more) as the stock XJ. they just dont settle nearly as far when loaded. the early blazers are not a spring under configuration. you may be refering to newer ones or possibly s10 blazers. when compared to the S10 spring i have from an early (84) s10, the s10 springs have much more arch. i like the blazer springs because they have thicker leafs and a higher rate. i am not looking for comfort (its a 4x4 jeep not a lincoln continental) as much as load capability.
i considered the ruff stuff perches, but their centering holes are only 1" apart. which would set the axle another 1/2" further back than the TnT u-bolt eliminators, which have a 1" and a 1 1/2" hole. remember i am using these in the reverse way as if you were using stock leafs. with the blazer springs at 26" instead of 23" of the stock, i actually need to bring the axle forward more as to not have too much set back. hope all this makes sense.

wont stiffer springs hurt articulation?

he must be refering to s10 blazers as the zr2 is an s10

Vanimal said:

wont stiffer springs hurt articulation?

he must be refering to s10 blazers as the zr2 is an s10

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well yes and no. the springs may be stiffer, but they are also flatter. a higher arch spring will not want to allow much more of an arch. thats where the shackles come into play. a longer shackle will give more throw hense giving you more suspension travel. (if properly set). the stock chevy springs actually allow alot of downward travel, especially with a decent shackle. remember when you are wanting more articulation, you are wanting more downward travel. downward travel only is affecting the top spring unless the straps are done tight against them. a spaced strap will allow the top spring to give more arch as the weight of the axle pulls on it. you will be arching the top leaf only and the remaining leafs will be at rest untill the straps max out and start pulling on the rest of the leafs. all this meaning, if the leafs are a stiffer pack, they can still give good articulation if assembled properly with correct shackle position, and strap gap.

ktm racer 419 said:

are you saying stock blazer leafs have less arch than stock xj leaves?

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2stix said:

no, i am not.

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2stix said:

well yes and no. the springs may be stiffer, but they are also flatter..

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contradictory?

do you even read the threads? those were answers to two different questions.

no, i am not saying that blazer springs have less arch than stock xj springs.

yes and no that stiffer springs can hurt articulation.

contradictory? no.

does that answer your question? do you have any useful information on how much your wheelbase was lost after lifting your jeep?

comparing the arch of two leaf packs from two different vehicles isn't really going to help you much. just because a pack is flatter doesn't mean it will flex better.

i think a stock xj pack has a spring rate of 655 or 745, depending on the arch the leaf packs have. if you are talking about 73-87 k10 blazer leaf springs they range from 1875 to 2775.

that is more than tripling the spring rate. unless you plan on regularly keeping about 1500lb in the back it will probably ride like a tank and flex like computer desk

actually the blazer is a K5 and their 3-1 packs are rated 1290# and the 4-1 pack is rated 1900#. compared to the s10 4-1 pack it is rated 1750#. which many people have used in their bastard pack. so if even using the 4-1 pack from a k5 blazer you are only gaining a roughly 150#load range. still all this means is a leaf stack can handle the rated load. when flexing you are only using the 1 top leaf. so the differences are very minimal. now comparing the stock XJ load of 745# is almost out of the question. try loading the average built XJs stuff to a stock spring pack and watch that sucker sag to the bump stops. heck just a good steel bumper/tire carrier, hitch, and a 33x12.50 tire would overload any stock spring pack. not to mention a small trailer. the s10 pack has been used many times with decent outcome. and i have never heard anyone say they were too stiff, only that they were too soft. so i am betting the K5 blazer springs will be just that little bit stiffer. i highly doubt it will ride like a tank, especially after loaded with all the accessories. as for flex, yes it may have slightly less flex i dont know yet, but it is a proven fact that a flatter leaf will flex better than a high arched leaf. and with the strap spaced to allow more flex and shackles set properly, i am betting they will flex just fine.

well there ya go.

the leaf spring chart i was looking at didn't have the k5 on it. just the k10 and you didn't specify in your previous posts. plus i couldn't find any info on the k5 spring pack.

when I talked to the local leaf spring shop about spring rate I was told that just adding a cut down main leaf from a stock pack would put the spring rate into the 900lb range.

i know what you're saying about a stock pack not being able to handle much weight in the back, it just seems like 1500 -1900 is going to ride like shit without a bunch of weight in it. unless you get a leaf pack custom made with the arch set and the load capacity you want

I have taken apart at least (6) s10 & blazer leaf packs & owned a sonoma as well. They are all spring under packs to my knowledge. When I built my leaf packs I took the main leafs from 3 s10 packs and cut the ends off to make my leaf packs because the other leafs have too much arch to go under a xj main leaf..

Anyway I agree with ktm racer about the adjustable leaf perches if you are worried about wheelbase.

actually i did specify in my previous post that i was talking about "full size blazer springs from early 60s-70"
again, the K5 blazer has a 3-1 pack and a 4-1 pack. 4-1 being 1900# and 3-1 being 1290# even if starting with the 4-1 and finding it is too stiff, i can remove a spring to make it a 3-1 and 1290# would be plenty soft.
but lets get off this spring rate thing and maybe someone can actually answer the original question. how much wheelbase did you lose when you lifted you XJ 4-5 inches. the 23" centering pin compared to the 26 centering pin is what i am more interested in. and yes i have allready mentioned i plan to use u-bolt eliminators that have offset pin locations. the ruff stuff ones are at 1" apart, and the UBEs have one at 1' and another at 1 1/2". this will give me SOME adjustability. i am just looking to see if anyone has actually measured what their outcome was after lifting with a spring pack (mostly bastard packs) with staying with the 23" center pin.
i have used measurements to calculate it all, but just thought id ask if anyone had actually measured. it is not really a big deal, i can customize and fabricate what i need. i was just hoping to come up with a simple, easy to find, and cheap spring pack swap other than the typical s10 pack and having to cut springs and still need to use the stock main leaf and 23" pin. we all know trimming the front of the rear fender is very limited because of the rear door jamb. so instead of actually loosing 3/4" wheelbase, i think using a simple swap pack that will gain 3/4" wheelbase would be a good alternative. i am sure many others would like the info.

I didn't lose any wheel base with a 4" lift...
4" On 31's... This is a bastard pack with s10 leafs with an xj main leaf and jks boomerang shackle

When fully compressed

Full droop

cool, thanks Maxx. i am surprised. i would have bet a 4" lift with stock leaf would have to move the axle a little forward. it sort of looks like it does in your last pick, but i realize that is at full droop. are the bump stops centered over the axle at rest?

I have about 3.5" lift (BP + MJ shackle), bumps are right over the tube as they were stock.

2stix said:

thats just it, stock blazer leafs have less arch, but are thicker leafs.

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ktm racer 419 said:

are you saying stock blazer leafs have less arch than stock xj leaves?

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2stix said:

no, i am not.

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This is the part that confused me. You said they're flatter, he asked if you were saying they had less arch, you said no. :dunno:

aintright said:

comparing the arch of two leaf packs from two different vehicles isn't really going to help you much. just because a pack is flatter doesn't mean it will flex better.

i think a stock xj pack has a spring rate of 655 or 745, depending on the arch the leaf packs have. if you are talking about 73-87 k10 blazer leaf springs they range from 1875 to 2775.

that is more than tripling the spring rate. unless you plan on regularly keeping about 1500lb in the back it will probably ride like a tank and flex like computer desk

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aintright said:

well there ya go.

the leaf spring chart i was looking at didn't have the k5 on it. just the k10 and you didn't specify in your previous posts. plus i couldn't find any info on the k5 spring pack.

when I talked to the local leaf spring shop about spring rate I was told that just adding a cut down main leaf from a stock pack would put the spring rate into the 900lb range.

i know what you're saying about a stock pack not being able to handle much weight in the back, it just seems like 1500 -1900 is going to ride like shit without a bunch of weight in it. unless you get a leaf pack custom made with the arch set and the load capacity you want

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There is no K10 Blazer that I am aware of. The K10 is the 4x4 1/2 ton truck. As far as I know, all full size Blazers were the K5. Most likely the chart just messed that up, or it was talking about the truck.

Either way, I may be wrong, but I'm pretty sure that comparing weight rating and spring rate are two different things. Weight rating is the total weight a spring can carry, spring rate is measured in pounds per inch, correct? So, for example, when people talk about front spring rate, it's generally somewhere between 150 pounds per inch and 250 pounds per inch, yet we know the front springs can carry a heck of a lot more than 150-250 pounds.

why is it that you guys feel the need to take all these quotes out of context? read on further and you will read that i am comparing the K5 blazer springs arch to s10 springs. (or any other leaf pack that would be used in a 4-5" lift) i go on to explain it in detail and should be pretty clear. are you guys reading the posts in their entirety? or is this just a (lets see how we can really screw up a thread) type of deal? i have allready asked to please keep this thread on its original topic, but apparently only one person understands that. (thank you MaxxXJ). it is no wonder people get so little info when doing a search. if i was to search 'wheelbase loss with lift" i would get this thread and get very little info on the matter. many of you guys only seem to want to do is try and find ways to show contradiction, and by taking quotes from different posts and out of context. i have read this type of thing more and more recently. and now that it is happening to me i am taking it a little personal. i came to this group because i found many of the members to be very helpful and considerate. (even to us dumb asses). but i am having real reservations about paying another membership fee. this thread has been a complete waste of my time.(well except for MaxxXJ's post). and other who may have read it looking for info on the original topic.
very sad, i thought i really liked this site.