Anyone filled the rear tires with water??

[Safari Ary]

if the water idea is important, cant you get 2 big coolers, fill them w/ water, and strap them to the cargo area?

The whole point is to add to the unsprung weight, not the sprung weight. By adding it to the cargo area you add to the sprung weight.

The reason I even brought this up is because I know a lot of the comp guys do this w/ their front tires to keep them planted on hill climbs. I wonder how they're dealing with all of these problems you guys are bringing up?

 

[xj_punk]

The whole point is to add to the unsprung weight, not the sprung weight. By adding it to the cargo area you add to the sprung weight.

The reason I even brought this up is because I know a lot of the comp guys do this w/ their front tires to keep them planted on hill climbs. I wonder how they're dealing with all of these problems you guys are bringing up?

it has come to my attention that it is not just done in front tires now. that is how it started, but the comp guys i talk to say they run it front and rear, as much water as they can possibly get in there. interesting idea, and i would do it if i had 35spl d60's f/r for sure!!!
unsprung weight RULESSSSS imo

 

[SouthernXJ]

So, why is it that manufactures boast about how light thier wheels are?

 

[robert.wesolowski@]

So if your dogging it, your wheel is spinning freely, you jab the brakes, the tire weighs about 50 lbs more than it should,,,,,,, what would happen?

Being that it is fluidic, my guess would be that the water would act as spinners would and keep rotating for a bit.

 

[Safari Ary]

So, why is it that manufactures boast about how light thier wheels are?

Because most people buying wheels that care about weight are concerned with going fast. A lighter rotating mass means quicker response from the drivetrain once the accelerator is depressed. Therefore, lighter wheels make you go faster.

Ary

 

[PlainWhiteXJ]

So, why is it that manufactures boast about how light thier wheels are?

Back in my college days I took a class (Internal Combustion Engines - good stuff!) from an ex-editor of Hot Rod Magazine. He was talking drag racing, but the point applies here.....

Everybody knows that if you want to go faster, add less weight. Well, when you are talking about acceleration, rotating mass (driveshafts, axles, gears, tires and wheels) counts roughly twice as much as non-rotating mass. It has inertia that needs to be overcome to translate (go down the road) and rotate. Even though XJs are not usually found on the dragstrip, rotating inertia can be important to acceleration and to braking.

Besides that, for what they charge for some shiny wheels, they have to have somethign to tout as a plus!

 

[MaXJohnson]

Being that it is fluidic, my guess would be that the water would act as spinners would and keep rotating for a bit.

Now we're talking. add some sprinkles and some little colored foil stars. Everytime you stop, the stars and sprinkles would still be going round and round. You couldn't see them, but you'd know they were in there, spinning around. A private little sprinkle party, right inside your tires.

this thread is cool without pics

 

[basalt51]

be sure to use heavy water to get the maximum benefit!!

 

[Ramsey]

i hope i get invited to the private spinning sprinkle party arty:

 

[OT]

i hope i get invited to the private spinning sprinkle party arty:

Ohhhh, I could soooo make this thread go to the Den with a response to that.

 

[Safari Ary]

Ohhhh, I could soooo make this thread go to the Den with a response to that.

No, you're not allowed, enough of my threads go to the Den without people like you trying to make them go there

 

[SouthernXJ]

Even though XJs are not usually found on the dragstrip, rotating inertia can be important to acceleration and to braking.

I know, that's why the water acts as the oposite by keeping more mass unsprung. Going heavier rather than lighter. So, my question was, why the rockcrawlers with the drilled out wheels. Seems you would want your wheels to be heavier, not lighter since we're not so much talking about rotational mass as just plain mass to cause the vehicle to be less top heavy and to increase droop.

 

[Go Go]

why not add tire slime, it's heavier than water and will seal up any punctures you may encounter. It works great on my mountain bike inner tubes but I was told not to use it in car tires. I do think the sprinkle party sounds good too, maybe get clear tires or acrylic wheels so you can see the sprinkles.

 

[Ed A. Stevens]

You guys are too funny :scared:

Adding water to the tire adds mass. Mass that rotates and is moving down the road. The brakes have to stop the tire mass and rotating water mass and the extra mass of the water speeding in a straight line (Newton's second law of motion: things in motion tent to want to stay in motion). The result is the mass of water contributes considerable stress and effort to work the brakes or the throttle.

Speed adds to the stopping effort, in an exponential way. Driving twice the speed does not require twice the force to stop, it requires four times the retarding force (F=1/2 Mass * (Velocity squared)). When you run heavy tires and rims it takes four times the work from the brakes to stop, and four times the work to achieve the doubled retardation of speed (more horsepower from the brakes and from the drive-train: why the drag racers go light). This extra effort required, and it exponential relation to speed, is why you will seldom find water (or any fluid in volume) on a vehicle operated at highway speeds (anything above 10 mph).

We see farm tractors (slow off-highway vehicles) run water in tires, and (before 4x4’s became common) old school adventurers ran agriculture tires and water on the back of fenderless Model-T’s and Model-A’s. The extra tire weight helped stability on hills and helped traction, and these adventurers were not in a hurry (the speeds were farm tractor slow). The adventurers who are still alive took it slow, and stayed well below highway speeds when running water in the tires (take the hint and keep it slow if you run water in the tires).

The competition rockcrawlers have applied the same use of water in the tires to control where the weight is loaded on the chassis (lower the total vehicle CG) and help them tune the balance of unsprung weight. It’s a tool to play with the prevent rollovers. If you want to do the same, it’s probably best to have two sets of tires and rims (the highway lightweight set, and the slow crawler set).

What about running water in the tire? There are guys in competition (and posters on the PBB) that have pumped water into tubeless tires. It gets messy, and most knowledgeable farm hands (those who have lived around lightweight tractors) would laugh at the effort. If you want to run water, fit a tube inside the tire and fill the tube with water. If you chunk the tire sidewall, or unseat a bead, the water stays inside the protected tube.

How do you get the water into the tube, and out of the tube? It helps if the rim used has two holes for valve stems: one for the tube stem and one stem for airing up the tire around the tube (just like tubeless tire).

You can pull the valve stem core (the Schraeder valve) and with a few fittings make a hose to fill the tube stem with a garden hose. Vacuum the tube closed, or pressurize it closed (more on this later), open the tap and fill the tube with the line pressure of the water hose. It’s best to do this with the tire on a scale to weigh how much you put into the tire (so you can balance right & left tires). When you get the weight of added water to where you want it, top the tube off with the pressure you want to run (and make sure to remove the valve core for the tire valve-stem).

Fully deflating the tube is one task where the extra valve-stem comes in handy; to deflate the tube by airing up the space between the tire and tube. If you did this first, before adding water to the tube stem, the tube would have been pressed flat from the pressure between the tire and tube. It’s hard to burp the trapped air with the tire mounted on the rim, because placing the tube stem at a high point (to push all the air out of the tube) can be difficult. If you want to really fill the tire fully, you may have to drain and refill from scratch (or go ahead and try to burp the air, for those who have to try).

Draining the water from the tube, how? Inflate the space between the tire and tube (use that handy second valve-stem). Just be careful to keep out of the path of the water jet streaming out of the tube stem, as the trapped water can get fairly rancid after a few weeks or months (or years).

You are now ready to run out and drill that second valve-stem hole in your high dollar rims, with that second set of trail-only ultra-expensive rhino-hide mudlugs, and the cost-is-no-object natural rubber drag race tubes?

Clear as mud? Good luck, and let us know if it’s worth the effort?

 

[hpi_jeep]

in our tractors i think it's a mixture of like 80% calcium chloride and 20% water.

i dont know the advantage of this but im sure there is a reason, maybe it's heavier.

(that might not be the name of the chemical, but it's the same stuff the county spray's on the gravel roads to keep dust down)

 

[basalt51]

Speed adds to the stopping effort, in an exponential way. Driving twice the speed does not require twice the force to stop, it requires four times the retarding force (F=1/2 Mass * (Velocity squared)).

When you run heavy tires and rims it takes four times the work from the brakes to stop, and four times the work to achieve the doubled retardation of speed (more horsepower from the brakes and from the drive-train: why the drag racers go light).

You provided alot of good info there Ed, but I think you got a little confused while explaining the above. Running heavier tires (say twice as heavy) doesn't require four times the force to stop, it is directly proportional, as you first stated. Or maybe I just didn't undertand how the heavier tires related to speed?

 

[Ed A. Stevens]

You provided alot of good info there Ed, but I think you got a little confused while explaining the above. Running heavier tires (say twice as heavy) doesn't require four times the force to stop, it is directly proportional, as you first stated. Or maybe I just didn't undertand how the heavier tires related to speed?

You are getting some of it right: twice as heavy at the same speed, requires twice the power to move or stop.

Now, double the speed and make it twice as heavy?

The doubled mass demands twice the braking power, multiplied by the four times (2 squared) of effort demanded by the speed increase, for a true result of eight times the effort to stop the weighted tire (2 cubed: because braking effort is actually de-acceleration, a third order differential equation, IIRC).

Maybe one of the math & physics wizards can elaborate?

 

[Buck Jackson]

in our tractors i think it's a mixture of like 80% calcium chloride and 20% water.
i dont know the advantage of this but im sure there is a reason, maybe it's heavier.
(that might not be the name of the chemical, but it's the same stuff the county spray's on the gravel roads to keep dust down)

Glad to see someone pointed this out. No one runs just plain water in their tires for agricultural or industrial usage. If you take your jeep to the local industrial tire shop and ask for fluid insertion, they will pump in a mixture of calcium carbonate (basically chalk) and water into your tires. The purpose is to prevent the water from changing volume with changes in temperature (prevents friction boiling and freezing), and to add more weight. They do not fill the tire totally up, but leave some air space inside. And as it has been said, this is absolutely NOT for highway usage. As Ed points out, it increases mass hugely and will cause all sorts of problems with driving and braking manners. Imagine trying to stop 44's with your stock brakes, good luck. If you have ever driven a tractor or forklift with fluid filled tires you will know what i am talking about, even at speeds of about 20mph you are bouncing and careening all over the place. They only use the stuff if the application calls for remaining very stable on the ground (ie telescoping forklifts that lift loads 50 feet in the air, tractors that need to function on a steep side grade, etc.) If competition guys use this on their rigs, their rigs are almost certainly trailer queens or they have more balls and less brains than me. Ary if you do this be prepared to go through brake pads like smarties, and probably bust u-joints left and right. And definitely have another set of "air only" tires to drive you to and from the trails.
Good luck,
Buck :canada:

 

[Tommy_Harrell]

I had a truck tire with water and loved it.
it was an old semi wheel/tire combo (steel 24.5 bud wheel) when full of water it was a hair over 350lbs and made a great winter weight for my pickup.

Tommy

 

[JeepinAudiophile]

Welding kegs on the end of my axles tomorrow, wrap em' in chains and they should work great.(15 1/2 gallons each) lol.