Effects of less lift

[ExplorerTom]

I've got a SAS on my Explorer. Dana 30 with 5.5" XJ coil springs from Rubicon Express. Plus a 2" body lift.

It's tall.

Possibly too tall. I haven't rolled. And I don't want to. I feel like it's come close. It leans a lot. I'd like to get rid of some of that height and stiffen the springs at the same time to fight the lean.

Here's how it sits now:
http://i642.photobucket.com/albums/uu143/TJUrbanek/Explorer/FEE5CF65-C59C-4C03-A7A7-6740576F2AA2.jpg (http://s642.photobucket.com/user/TJUrbanek/media/Explorer/FEE5CF65-C59C-4C03-A7A7-6740576F2AA2.jpg.html)
http://i642.photobucket.com/albums/uu143/TJUrbanek/Explorer/1a561fe4937026aa993288acacc5093a.jpg (http://s642.photobucket.com/user/TJUrbanek/media/Explorer/1a561fe4937026aa993288acacc5093a.jpg.html)

Here's a video coming off the Rock Slab at Metberry where you can see the tippiness:

http://youtu.be/raxv4Oi4ilU

I can't undo the body lift. My bumpers and sliders are built to that height. I wish I could undo it.

as I see it, here my options:
install shorter lift springs
cut the springs I have now

I've done the measurements and can get very close to the published spring rate of 184lbs/in on my springs. I can therefore adjust the active coils in the formula for spring rate and see the effect. If I take out 3 coils, I will get pretty close to the 3.5" lift springs from Rubicon Express. The problem with cutting the springs is that while I know the spring rate, I don't know the resulting height. This is where getting the RE springs makes it easy.

OK, with all that aside, what does the new lower height end up doing to the rest of the system? My driveshafts were built to the current height- that shouldn't be an issue. What about alignment? I come from a long line of FWD and IFS, this solid axle is still pretty new to me. I shouldn't get any binding or interference with the trackbar/drag link/etc with any other thing as it could be in this "height" with my current springs if I hit a bump.

Thoughts? Should i cut or buy new springs? Issues?

[xaza]

How soon you trying to make the change? Would 4.5" help you? I am thinking that after the weight of the cage is added on I may be wanting a 5.5". What are you running for a leaf spring? Wider off set tires would help too.

[gm4x4lover]

It didn't look that tippy to me but I was just watching on a flat screen. I would pull the body lift out. I know you said that the bumpers and sliders are made for it with the body lift. The suspension seems to work really well how you have it tuned now. The body lift really isn't performance adding. I will pull that and maybe up grade the shocks.

[ExplorerTom]

How soon you trying to make the change? Would 4.5" help you? I am thinking that after the weight of the cage is added on I may be wanting a 5.5". What are you running for a leaf spring? Wider off set tires would help too.

The 4.5" are softer than the 5.5" so I don't think that would be a good idea. Leaf springs are Chevy 1500 63".

[Hypoid]

It didn't look that tippy to me but I was just watching on a flat screen.I have a ridge in my office chair from watching that vid.




OK, with all that aside, what does the new lower height end up doing to the rest of the system?The castor angle will change, the anti-sway bar will not be as effective, the track bar will push the axle to the passenger side, the steering wheel will be rotated when the tires are pointed straight ahead. Hopefully, your system has enough adjustment built in for the new ride height.




Should i cut or buy new springs?The cut springs might prove difficult to resell if you don't like the result. I have some RE coils in my stash, I'll get a part number tonight. If they are the same part you are considering for replacements, I'd be OK with letting you install them for a reference point.

[ExplorerTom]

Ok. Let me know on the springs.

[Brad]

This is a problem I have as well. Stiff lift for expedition gear and tall tires. I am leaving my lift alone and getting wider tires to stabilize the truck.

[redneck23ms]

did you have the sway bar connected? if not try running it connected and see how it works. if the sway bar helps but limits flex too much you could go with an antirock swaybar or one similar

[ExplorerTom]

My suspension is very compliant. I'm thinking stiffening it up while lowering it will help.

Wider track will is also being considered.

[jayson44]

x2 on the sway bar. get an antirock if you can, that will help keep you stable + flexy.

also, I'd stay away from cutting the springs as that could mess up their ride quality. you might lose height, but you'll also lose feel and the progressiveness that they are designed to have.

I'm not sure castor will change a whole lot...it will, but probably not enough to notice. it is something to look at, though. and x2 on everything else Mike said about needing to adjust your steering wheel & trackbar.

J.

[mattmcl]

Would it help to increase the wheel backspacing, or use wheel spacers?

[gm4x4lover]

Would it help to increase the wheel backspacing, or use wheel spacers?

I think what you ment to say was "Would it help to increase the wheel offset or use wheel spacers. Backspacing is the measure from the hub mounting surface to the back of the wheel. Increasing Backspacing would make the track with narrower and the vehicle less stable. Increasing offset or using wheel spacers accomplishes the same thing. Some times manufactures only offer standard offsets and that is when the wheel spacers come into play.

[mattmcl]

I think what you ment to say was "Would it help to increase the wheel offset or use wheel spacers. Backspacing is the measure from the hub mounting surface to the back of the wheel. Increasing Backspacing would make the track with narrower and the vehicle less stable. Increasing offset or using wheel spacers accomplishes the same thing. Some times manufactures only offer standard offsets and that is when the wheel spacers come into play.

Yup! Thanks.

[Hypoid]

Let me know on the springs.Turns out these are not even RE springs. When I searched the part number, I found they are pro Comp, 3-inch lift springs, with a 230 lbs/inch rate. :frown:

[H8ROADS]

I agree with the body lift removal suggestion. You clearly have a ton of room in there to stuff the tires and while you might get a little rub at full flex without the body lift I bet that would lower your COG enough to make a difference.

[Chris]

I'm of the 'remove body lift' opinion as well. It sounds like it'd involve a lot of work but probably the best way to go anyway.

[Jim]

I'll be a contrarian here.

I have a hefty suspension lift and, what many consider gaudy and excessive, a 3" body lift.

If you're looking for a lower center of gravity (COG), consider either reducing your suspension lift or widening your stance.

Ask these questions:
1) How much mass (weight) do you have in your truck's body when loaded (the body, people, gear). Is your fuel tank mounted to the frame or the body? I'd guess frame. If body, add that in too.
2) How much mass (weight) do you have in your truck's frame / engine / trans / xfer case / drivetrain / fuel tank [6lbs per gallon of fuel] - the mass sitting on those springs less what would be in question 1.

My assumption is that #1 would add up to 1/3 of what #2 would be [somewhat a guess - do your own figures].

Would lowering your body, which would net you 1/3 "gain" for each inch lowered vs. the same inch lowered in suspension, be worth the hassle?

Now, the same 1" suspension decrease will net you 2/3 gain having #2 be lowered AND the 1/3 gain as #1 will also be lowered.

So, I'll ramble into another dimension... (or a rant - not aimed at anyone)

Suspension flex

In general, we want all four tires touching the ground as we want traction for forward motion. Well, when we get crazy flex we often need some upward flex. It's the upward stuff we have a problem with (wheels rubbing fenderwells). Bump stops will keep fenderwell rubs in check. Now, the royally flexed out tire probably isn't going to have much traction as the spring between the axle and body isn't compressed to push the tire into the ground. We're not going to get much traction. About all the crazy flex is good for is a curious photo op. The crazy flexed out tire will spin while the tire buried into the fender isn't getting any love from the open diff.

In step lockers. Skip going crazy flex and just stick in front and rear lockers. When into the one, or two, wheels "hanging" with low to no traction, the firmly planted tires will give the forward motion.

Coming back to square one... drop some suspension lift (your u-joints will thank you for it), stick in bump stops to reduce wheel-body rub, consider going front and rear lockers to keep forward motion rolling.

This might be appropriate :brody:

[Robert B]

i can help you with this but would need to know if you have done anything on it and the big one is where are you worried about rolling wheeling or street? because stiff springs wheeling increase the possibility of rolling and the tires wont move into the wheelwells .... also id like to know if those that say "take out the body lift" have ever custom made mounts for bumpers and sliders because thats an insane amount of time and effort.. and from the video you took a while to turn to the right for that obstacle to me but didnt seem tippy to me .... and welcome to the world of coil springs lol lots of money to do them and you usually just have to buy new springs to change height and maybe the bars associated with them if they dont have enough adjustment. the rear leafs seem pretty flat and like you are running 1 or 2 so if you dont have a block or lift shackles you will need to find springs that are meant to be negative arched to put in there

[Haku]

It might have been said and I didn't see it, but rather then stiffer springs I would go with stiffer shocks. This will allow you to keep the articulation and more compliant ride of the softer springs but still get decent road handling. This in combination with a decent set of sway bars should really be all you might need. With the coils in the front, if you do new springs I personally would keep the same spring rate and just get shorter springs and invest in some stiffer shocks (adjustable/tunable even better...i.e. Fox, Sway Away, King or FOA).

That said, it does look taller then it needs to be. I've always been a believer in the "only do enough lift to clear the tires you want to run" philosophy. I know that when I dropped my Toyota crawler 4-6 inches from what I bought it, that it made a big difference in the stability. I've since put wider axles under it and completely re-did the front suspension with 4 link and coilovers, but just lowering it made me feel much more comfortable in tippy situations. It leaned less on off camber sections and while driving "on road" and I managed to do it in a way that kept almost as much travel as I started with by taking lift blocks out and raised the leaf spring mounts up into the frame in the rear and took a few leafs out of the front pack and made shorter shackles.

Accomplishing the task of lowering the rig is simple in theory but harder in application but its definitely doable. I think you might surprised how much even a little bit lower CG helps with that tippy feeling.

[ExplorerTom]

i can help you with this but would need to know if you have done anything on it and the big one is where are you worried about rolling wheeling or street?

What have I done to it? Just a SAS with SOA. On the street with the front sway bar connected, it is quite sure footed. No concerns there.

Leaving the the front sway bar connected on the trail isn't a great option because where it got relocated to limits my steering (inside tire sidewall rubs sway bar). With it disconnected, I have lock-to-lock capability.

the front uses Rubicon Express 5.5" XJ springs. The back uses Chevy 1500 '63" springs' with Explorer lift shackles.

I might try try some Chevy 3/4 ton springs with OE shackles. That way I lose a little lift with the shackle but the springs should bring it back up. And in the front some type of OME spring with about the same height but a higher spring rate.

The path to my current setup was not a straight line. If I knew I was going to end up here, I would not have done the body lift. But such is life.

Stiffer shocks I don't think would do anything because they can't stop lean, they just slow it down. This could be beneficial for a lean caused from bounce, but a slow steady state tip needs a stiffer spring to help control it.

[Haku]

Stiffer shocks I don't think would do anything because they can't stop lean, they just slow it down. This could be beneficial for a lean caused from bounce, but a slow steady state tip needs a stiffer spring to help control it.

I suppose thats true. I've read recently that a lot of the suspension tuners for KOH and other offroad racing series have been asking for MUCH lighter spring rates compared to the past, and can often dial out the downsides with shock tuning. That said, they also say the springs need to be just heavy enough to suspend the vehicle and carry the loads it needs to. I do know that bunch of guys in Colorado have started going with the "light spring" method with their buggies and harder core offroaders it seems like its paying off in both slow and fast speed applications. It is certainly a fine line to tread sometimes though.

One way to get a bit of the best of both worlds is to look at progressive springs that start out softer and get stiffer as they compress. Also, as you get stiffer springs, you'll have to worry about getting into coil bind (where the spring compresses fully and you get a hard stop) so it could possibly limit your suspension travel too. I'm not saying this is happening, just that its stuff to think about. Torsion bar style sway bars like the Curry Anti-Rock ones are worth looking at since they are designed for long travel applications and have varying length arms so you have more options on where to put them.

[dieseldoc]

cutting coils is bad.
you heat them as you cut. thus siftenning them.
go get a set of coils from a full size bronco.
the stock set wiil get you what you want.
they will lift a TJ some 3+ inch so you might need a 2 inch lift set but they are much stiffer and thicker thus leaving you the option to heat and soften them.

[GPP33]

cutting coils is bad.
you heat them as you cut. thus siftenning them........they are much stiffer and thicker thus leaving you the option to heat and soften them.

So which is it? Will heating stiffen or soften them? I don't mean to be a dick but both are incorrect.

A spring rate is dictated by the thickness of the wire, the length of the wire and the modulus of elasticity of the wire. Modulus of elasticity is how much the material will defect with a given load normalized by the cross section. It doesn't care how hard the material is, a steel at 20 HRc has the exact same modulus of elasticity as a steel at 65 HRc. The only way you can change the spring rate (aka soften or stiffen) of a spring is to change the length of the wire. Actually you can really only decrease the length which will increase the spring rate. You can't make a spring softer by heating it, you can however decrease the yield strength to where you can plastically deform it, at that point you've ruined the spring though. Please don't take a torch to a spring to try and soften it.

[gm4x4lover]

I think what he means is most people cut off the progressive rate part of the springs and therefore they become stiffer.

[ExplorerTom]

Well I accomplished my ultimate goal. I swapped the soft Rubicon Express 5.5 XJ coils with a set of firmer 7.5 ZJ coils from Iron Rock Offroad. Leaving the ZJ coils as is would have given me an additional 2" of lift and would have still been a little softer than I wanted. But after plugging the numbers into the spring rate equation, I discovered that if I cut 2 coils off, I would be at about the same height as before (maybe 1/2" lower) with a resulting spring rate of 280 lb/in. I was shooting for 290 lb/in, but 280 is close enough.

I know now I lost some flex, but I've still got a ton. The on-road manners have been greatly improved. I'm much happier overall with this setup now.

[96EXXLTinCO]

Will be interesting to see what you think of the change on the trail.