Lowering XJ

Ok speedy if they arent realy meant for what some of us want to do such as lowering and making them fast and if the factory never intended it at all why did 4banger MJs kick the crap out of every one in thier clase in road raceing. I'm just like aalarge majority of us on NAXJA we love to build things and work with our hands and be a little diffrent. I personaly have a 89 xj on 35s and soon will have a lowered MJ and a MJ sitting on atleast 38s. we're hear to talk about things and help eachother out no mater what they want to do. hell if some one wanted to make a boat out of an XJ we might laugh alittle but damn if we wouldn't help the guy the best we could.
 
Now you got me thinking again... when my projects are done I should have 2 spare perfectly operational 4.0's laying around... they would power a boat nicely.

Sorry, back on topic!
 
Ed makes a great point about the front bumpstops...

I knew all along that the typical MJ has longer rear bumpstops (and shackles) than the XJ... when I lifted my 89 XJ I used the front bumpstops from my 89 metric-ton MJ (had trimmed the "bells" that grab the springs on that set) and yesterday confirmed that they indeed are longer - by maybe 1"- than the XJ variety that they replaced.

So there is some cross-use possible now that we know about the differences...
 
I saw the Hot Rod MJ's @ Brainerd Intl Raceway several times. What a blast! They kicked everything else's a**. They ran in a tight, drafting position, bouncing off each others' tails, hangin' the rear end sideways. The peopel couldn't bleiive they were only 4-bangers.
Yes, there is a legitimate interest in making the XJ a street-mod, tail happy powerhouse.
On the lowering, my '97 5-spd 4.0 has sagged about an 1 1/2inches already, due to hauling, towing and extra 'S' goodies (sub, skids, spare, stuff).
I'm wondering if the late models (97-01) need to worry about driveline vibes when you go DOWN, just liek when you go UP?
I'd love to be able to drop it about 2-inches up front, but have the hydraulics to go the same distance UP whn the situation called.
Is that too much too ask?
G
 
I'm trying like hell to find any info or pic fro, the mj racing days but haven't had much luck.
Hydralis would work but air bags would do the same job and ride better and be alitle cheaper. i dont think you'd have drive line problems if you lowered it but you may need to shim the axle to get the drive line angles right.
Back in 97 I got my first XJ and it needed motor so i rebuilt it and but a header and a cam in it. That thing was very quick and was amazing on the highway. from about 65 till the limiter kicked in it would run with just about any v8 at the time and was just abunch of fun to drive
 
It could be possible to do a shackle flip like the full size chevy guys but in reverse. If you flip the shackle up you would get around a 2 inch drop and you could always use a longer shackle. This is just an idea and I haven't looked to check for clearnce issues. But I thought I'd throw it out
 
What about redrilling the rear shackle mounting holes up closer to the body. there appears to be about 1 1/2" of room. maybee add a plate to the exterior prior to drilling if you're worried about the new hole being too close to the old one. Replace the shackle with one similar to a boomerang with the concave side towards the rear bumper. Trim the bottom of the bumper as needed.
This might require a longer main leaf, very flat leaf or flipped leaf added to the pack. I'm not sure. Just thinking out loud.
Another option(and this may be way out there) would be to have the foward spring eye wrapped in the opposite direction. If it could be done then you might loose 1 1/2"(?).
What about a coil/four link conversion with shorter (custom?) coils?
I may be out of my mind here, would'nt be the first time. But then again...


T just babbeling Bent
 
The great thing about Jeeps is their power to weight ratio that makes them fun to drive on the street as well as off-road, so we are here to cover the until now ignored performance side of our great vehicles. [/B]
Click to expand...


Dammit, now that is the exact point I'm trying to make to anyone as a counterargument when I hear that Jeeps are'nt designed for speed. That is complete horseshit. I've got that same power to weight ratio as an Acura Integra Type R. I consider that an excellent benchmark for a fast vehicle. I'm glad someone else out there thinks the way I do about Jeeps.....the ultimate sleepers.
 
This is the forum that I've been looking for.
The XJ can be made to do almost anything. Obviously it can offroad, but it can race and drag too. It might even autoX!:D THAT would be something. I'd like to see a rally Cherokee, though. That would make everyone happy. It would be built for the road, but would sling gravel to make the offroaders happy.

The naysayers should be reminded of the Archer Bros. Jeeps after the first outburst.

Now, lowering a Cherokee will free up a few horsepower at speed. This is because the Cherokee is a brick. It will also increase fuel mileage. Combined with a front airdam, the results might be pretty good. Handling might also be better at highway speeds or in crosswinds. This is real world performance. Over 99% of the Jeeps here get driven on the highway.

Is it ricey? No, not if done properly. Just like the rear wing on a FWD example above, it can be done right or wrong. It also requires some thought. Things are not always as they first appear. A FWD car produces downforce on the drive wheels as speed increases. A lowered FWD might produce even more front downforce. Like a seesaw, the rear lifts up. Even though the rear wheels aren't driven they do need to be pressed to the pavement, otherwise they might want to swap ends under hard braking. They also might toe out or lose camber when lifted.

Look at the hood on the front of a Civic TypeR hatchback. See the angle of the hood? Imagine tilting the hood of your Cherokee forward to that same angle. Think you'd get some front downforce at 80mph?:LOL: I use the Civic as an example because it was aero tested against sports cars in a German car magazine. Germans test things very well.:)
 
Welcome to the forum! You sound like you have quite a bit of knowledge to add to the community... I like that.
 
Looked at the rear of mine, bumpstops were broken off long before I bought it, shocks now limit up travel with no interference conserning the fenders with stock tires.
SOA usually gives about 5" of lift - what if you went SOA with a 3" AAL? This would stiffen the spring rate - usually a good thing for handling - and using a shorter than stock shock? In theory this would net about a 2" drop, and the shock mount that gets in the way could be relocated to the other side of the axle - use somethinf like the crossmember that some people use that angle their shocks over (Cross Enter? I remember seeing a bought one).
For the front - what about using springs from a 4 cyl w/o A/C? Dunno if this works on Cherokees, but using the lightest factory springs available to drop the front of a big block car is an "old school" trick from way back. Need to increase the roll-bar diameter to get back the wallow resistance on the twisties. Maybe the Currie Anti-rock set as stiff as possible?

Not my cup of tea, but if someone wants to lower their Cherokee, thats fine. Just, PLEASE, don't put a fart tube on the exhaust - they annoy my dog (and me!).....
 
Didn't say the shocks lived well, but they still work. Basically it's an emergency back-up vehicle, just one step from being a donor. Just wanted to show that it will work, the shocks bottom out at about the same time the axle hits the frame.

Shocks are rusty, show some seepage, and the lower mounts are bent a little down. Have no idea what brand or part number, might have a little Monroe blue on them, but I can't say for sure. $100 and I drove it home, so I didn't ask alot about the previous abuse.
 
XJ Saga said:
Dammit, now that is the exact point I'm trying to make to anyone as a counterargument when I hear that Jeeps are'nt designed for speed. That is complete horseshit. I've got that same power to weight ratio as an Acura Integra Type R. I consider that an excellent benchmark for a fast vehicle. I'm glad someone else out there thinks the way I do about Jeeps.....the ultimate sleepers.
Click to expand...

Agree 100% with that argument. I've spent the last eight years slowly modifying mine and it's still a work in progress.
I haven't lowered my suspension yet but I have installed poly bushings to the front antisway bar and the UCA's and this has tightened up the handling nicely. Since I have the UpCountry off road package, I have 1" coil spring spacers at the front which I could remove to lower the front by 1". My XJ is an oddball export model that also has a rear antisway bar so I could do with some poly bushings for that as well.
I've also installed the front air dam from a '91 GMC Jimmy. This has reduced front end lift to make the Jeep noticeably more stable at speed and in crosswinds.
The XJ does indeed have a very good power/weight ratio and it's not difficult to improve on that. I've gained ~50hp (crank) with my performance mods while at the same time I've also lightened my XJ by 85lb. Stock was 19.1lb/hp (with my 165lb body in it), now it's 14.9lb/hp.
 
I guess any benchmark of 'performance' needs to factor in the intended & actual use of the vehicle, and how well it performs or usefulness is improved with a given change from OEM.

The off-road side of NAXJA addresses this on a daily basis within that aspect of modification....and lots of the suspension tech crosses back & forth, even if with opposing goals (lift & flex vs drop & tight road handling) LOL In case anyone hasn't noticed, folks don't brag on rear sway bars over there ;)

What makes XJs & MJs pretty amazing to me is their versatility. The platform can transform from reliable daily transport to trail rig to road or drag-mud-sand racer and back with a simple day of suspension & axle? swapping and adding appropriate tires/wheels. It may not excel at any particular aspect without some trade-offs elsewhere, but a basic changeover involves just some $$$ in mostly bolt-on parts and a bit of wrench time.

I am interested in hearing more specific tech about basic XJ/MJ suspension lowering and how it helped your Jeep...Part #s and sources are good :)

I'd like to learn some OEM Jeep spring rate & length/ride height info...

Dr Dyno, forgive my ignorance, but you mean to say that the UC package on your 92 is a 1" spacer? Hmmmm I always thought it was a longer and/or stiffer coil.

I have heard TJ front coils offer a little lower ride height than OEM XJ...If so, there ought to be plenty of those available for cheap-to free.

Also think that a springunder/over leafpack rear axle isn't out of the question for a multipurpose XJ. Before I "XJ'd" my MJ D44, it had both sets of spring pads attached, and could have gone in either way. Simply undo brakes, shocks, pinion UJ, U-bolts, & shackles...roll out, roll in, attach, bleed, etc... It's almost fun when ya get used to it :)

A few off-road parts & tricks that would switch hit nicely are ORGS ACOS (trick adjustable 0" to +3" front coil spacers) and adding a traction link(s?) to the shaved rear axle.
 
woody said:

Dr Dyno, forgive my ignorance, but you mean to say that the UC package on your 92 is a 1" spacer? Hmmmm I always thought it was a longer and/or stiffer coil.
Click to expand...

You're probably right about the longer coils. I just haven't had a non-UpCountry XJ to compare mine with because all the XJ's sold out here came with the offroad package as standard.
I forgot to mention that the UpCountry package also included heavy duty gas charged shocks, and they really do perform very well.
 
The spacer seems strange... my '01 Upcountry has stiffer/taller springs, the stiffer shocks and taller bumpstops. There is a rubber coil isolator as on all XJ's, but no additional spacer to my knowledge. Do you have the rubber isolator and a spacer between the coil spring & the body, or just one item?
 
Whew...thought I had lost my mind :) I figured that if there was a 'spacer' of significant height, the cheap-o off-road folks would have been raiding the junkyards and stacking these things up for added lift. As it is, the rubber 12mm isolators can be stacked to tweak the ride height.

This is where Off Road General Store's ACOS is sweet... front ride height can be easily adjusted within a 3" range to get the altitude where it's needed for different uses. IE: a 2" drop for cruising and a +1" lift for light trail use or load carrying

Coil Theory Question: Removing (cutting off) a wrap or two from a coil spring increases it's stiffness - Yes? If so (asssuming the coil is linear & not progressive rate) is there a simple equation that one could plug in spring rate # and number of wraps to predict drop and/or rate increase?
 
You must log in or register to reply here.

Similar threads

N
  • Locked
Lowering An XJ
Replies
0
Views
450
NAXJA_Archives
N
J
D35 Leaking
Replies
1
Views
152
lawsoncl
L
A
T-Case Problems?
Replies
7
Views
272
Ol Blue
Ol Blue
T
Daily driven for a year then DOA! Dreaded crank no start. Please help
Replies
15
Views
295
Da XJ nut
Da XJ nut
P
1999 XJ is getting the best of me. No Start.
Replies
13
Views
441
Anak
Anak
Back
Top