aquaplaning !!!

[tntoyota]

Not sure how this has anything to do with it. AWD's can hydroplane. Hydroplaning is more about speed than traction, here AWD's are at the same mercy's as 2WD's.

A heavier rig just means you have to be going a lot faster than a lighter rig.

Yeah!...And with enough speed you can get the Edmund Fitzgerald to plane........



Are you sure bout that?


My theory,


your doin 70 you hit water and the left front is the first to hydro.


open diff law states: "the wheel that slips is the wheel that grips"


with engine torque suddenly applyed to the L. front wheel it will dig through the water because it has the engine's torque and get to the traction.



diffs are blind they go by feel you cannot tell me this does not apply in any order, it will always follow the weakest wheel.



2WD's are at the mercey of AWD's, AWD is far supirior*. (A streetable version of 4WD but not true 4WD)


This is why I have an 80 and not all 2WD's


I spec'd a 4WD and this one came up, no 2WD or P.T 4WD conversion no tranny loss, I spec'd it.


ask all those (older) porsche (C4) guys they'll tell you.


Bugatti only did it becouse of the audience poll .


* excluding fuel economy

 

[tntoyota]

Oh don't worry, they can. Scared the **** out of myself in an Evo 9 a few times now

Were you wearing BFG AT's at the time?




or racing (street) tires?


Which brings me to another point....................counter steer


counter steer with an AWD or FWD and it's, bye bye Betty!

 

[Kalawang]

I doubt tires help at all. My 80 aquaplanes when it hits water puddles at speeds as little as 60 kph and worse yet, the splash comes up on the windsheild and blinds you. The only defense I have is to pay more attention to the road after a rain.


Kalawang

 

[chibo]

Were you wearing BFG AT's at the time?




or racing (street) tires?

I run 35" BFG ATs on the 9 They were race tires, so it's to be expected.

 

[IdahoDoug]

TN,

Incorrect. You're not going to grind down through the layer of water upon which you're hydroplaning. Not happening. And yes, the Edmund Fitz will hydroplane if you put it on rubber tires and run it down the road. Repeat after me - "Water behaves like a solid at high speeds"

DougM

 

[tntoyota]

TN,

Incorrect. You're not going to grind down through the layer of water upon which you're hydroplaning. Not happening. And yes, the Edmund Fitz will hydroplane if you put it on rubber tires and run it down the road. Repeat after me - "Water behaves like a solid at high speeds"

DougM

Yeah if your talkin this,


http://www.youtube.com/watch?v=E0RM6JWPgZI


or this? ,


http://www.youtube.com/watch?v=j3jMSO9j628


thats just like saying the truck in the link (I posted) would do the same thing, skimming water on BFG AT's?


the wheels are driven, not just along for the ride.


I know the high speed water thing but thats way beyond an 80's threashold.

to skim an 80 would be 4" water/ 90+ mph?

factors:

lift before, nail it during, saw the wheel, tire's, air pressure, tread depth in relation to speed, weight, driven wheels, .

 

[Brian Macgyver]

Were you wearing BFG AT's at the time?

Another big gainful acclaim for BFG's. They are great!!
Not! The BFG tag stands for Big F-ing Gimmick! My last truck came with a set if them on it. They would not grip rock. They would load up in snow or mud. They would dig holes in gravel. They were over-advertised junk. The only redeeming feature of the tire was that they kept the same design for ten or more years. But now they are not the same, yet no better. They have changed the tread pattern without finding any improvement. They still fail to grab terra firma!
P.S. The do have a tough sidewall and carcass. I'll give them that.

 

[Doc]

with engine torque suddenly applyed to the L. front wheel it will dig through the water because it has the engine's torque and get to the traction.

You're assuming you have enough run out on dry pavement to matter.

An 80 will hydroplane, as a few in this thread have testafied to. If you can't accept that... then nothing I saw will change you mind.

 

[TX_TLC]

You're assuming you have enough run out on dry pavement to matter.

An 80 will hydroplane, as a few in this thread have testafied to. If you can't accept that... then nothing I saw will change you mind.

Did you check out his poll too?

 

[Doc]

Did you check out his poll too?

I think I've found a new candidate for my ignore list. Also, why does he feel the need to yell so much?

 

[jonheld]

lift before, nail it during, saw the wheel, tire's, air pressure, tread depth in relation to speed, weight, driven wheels, .

Have you ever taken a physics class? Strike that, I just answered my own kweschun.

 

[TCH2FLY]

the wheels are driven, not just along for the ride.


I know the high speed water thing but thats way beyond an 80's threashold.

to skim an 80 would be 4" water/ 90+ mph?

factors:

lift before, nail it during, saw the wheel, tire's, air pressure, tread depth in relation to speed, weight, driven wheels, .

You are incorrect that the difference relates to the tire being "driven". The hydraulic action of water does not change just because the wheel is used to propel the vehicle.
In aviation the phenomena is covered thoroughly. We recognize three types of hydroplaning but only two are applicable to this discussion. BTW before you tell me it isn’t the same the NASA state the theories are also applied to highway vehicles.
1. Dynamic Hydroplaning: Dynamic hydroplaning is a condition where the tire is lifted completely above the surface of the runway. As little as one-tenth inch of water combined with the “NASA critical speed” of the tire is the causal factor.
2. Viscous Hydroplaning: Viscous hydroplaning can occur at slower speeds and rather than the water lifting the tire from the pavement, the tire slips on a thin film. This occurs on very smooth surfaces.

The formula to determine the “critical speed” in layman’s terms; the hydroplaning speed of a tire (in knots) is 8.6 times the square root of the tire pressure in PSI ( pounds per square inch). (1 knot =1.15 MPH)
So regardless of the actual weight a LC with a tire pressure of 38 psi would theoretically hydroplane at 61 mph. And yes the surface conditions and the tire tread will cause the actual speed to vary slightly.

 

[TX_TLC]

I think I've found a new candidate for my ignore list. Also, why does he feel the need to yell so much?

x2...even StuckinGA wasn't this bad....was he?

 

[IdahoDoug]

Mike's got it. It's an inviolable physics situation. I know it seems puzzling and agree that it's something you have to stop and think about. Then read some more about and finally understand. Somewhat counterintuitive.

The video is cool, and I've seen it before. Little relation to an automobile hydroplaning behavior, though.

DougM

 

[tntoyota]

Did you check out his poll too?

ok, gotta point there!

I think I've found a new candidate for my ignore list. Also, why does he feel the need to yell so much?

yeah ask a question and blow you cred,

You are incorrect that the difference relates to the tire being "driven". The hydraulic action of water does not change just because the wheel is used to propel the vehicle.
In aviation the phenomena is covered thoroughly. We recognize three types of hydroplaning but only two are applicable to this discussion. BTW before you tell me it isn’t the same the NASA state the theories are also applied to highway vehicles.
1. Dynamic Hydroplaning: Dynamic hydroplaning is a condition where the tire is lifted completely above the surface of the runway. As little as one-tenth inch of water combined with the “NASA critical speed” of the tire is the causal factor.
2. Viscous Hydroplaning: Viscous hydroplaning can occur at slower speeds and rather than the water lifting the tire from the pavement, the tire slips on a thin film. This occurs on very smooth surfaces.

Just like the race cars or any thing other on a wet track or road?
then you dont even need water for that......tires when they get hot start to melt and "drifters" hydroplane on the hot rubber.



The formula to determine the “critical speed” in layman’s terms; the hydroplaning speed of a tire (in knots) is 8.6 times the square root of the tire pressure in PSI ( pounds per square inch). (1 knot =1.15 MPH)
So regardless of the actual weight a LC with a tire pressure of 38 psi would theoretically hydroplane at 61 mph. And yes the surface conditions and the tire tread will cause the actual speed to vary slightly.

Oh, so sorry so dumb I thought were talkin AWD Land criuser's here but the Hydro dynamics of a 747 doin' a buck fifty+ on a flat run way and 2wd's apply to.


I did not say it was impossable, but out side the normal envelope.

x2...even StuckinGA wasn't this bad....was he?

I'll keep my chat down, you bunch of Elietest's really gota good thing going here, there would be no fourm if Toyota imported what you want or would even let you order one, Did you see my post..........


But just like a typical American let power's that be (all over you) alone dont do a thing about it just continue to take it...................


your system is working (to keep you right where you want to be) great


Magazine readers are more together than you Elietest's


They get more accopleshed with less tools.

And they only got a factory air locker SA HD front axl Jeep to show for it, could you got one those a few years back?


Do all cruiser owners wave at eachother? (no)

I'll see my self out, thanks been a real hoot!!!!!!!

Bitch and complane but dont do anything about it (the American way). You sink $40k in a rig I'd like to finance a brand new one .

 

[little_joe]

So regardless of the actual weight a LC with a tire pressure of 38 psi would theoretically hydroplane at 61 mph. And yes the surface conditions and the tire tread will cause the actual speed to vary slightly.

Dang it sucks when someone replies with actual scientific info, doesn't it?Awesome info, Mike!

I wonder then what the tread compound, tread depth, and tread pattern do to impact the formula.

At this point would not "channels" that expel water or tire surface area / contact patch - all other things such as depth, compound, etc being equal - increase the speed required to hydroplane?

I speculate yes, and here I am with Nay, this is an area where the BFG AT's suck. I ran them on a mini and found their only redeeming quality to be they were round and tolerable onroad in dry weather - they were terrible in rain, not good in constant lake effect snow, a slick offroad except in the dry (where any tire would grip, incl the stock GY RT/S). MTR's and Bridgestone Dueler MT's did incredibly better in every condition on the same truck. So even if I'm wrong scientifically, my empirical evidence suggests there is something w/ BFG AT's that makes them below average.

 

[KliersLC]

snip.... I am an idiot...... snip
.

See how easy that was?


Good riddance, now if we could get him to leave the truck section too.

 

[TCH2FLY]

I considered posting and trying to explain it to him again but I can see it isn't worth my time. I think he may just need to get a new keyboard like this, it might help him out....

 

[re_guderian]

So does the plane take off or what?

























And by the way, in AZ you don't have to worry about driving in water too much...

 

[IdahoDoug]

Little Joe,

The compound, tread pattern and depth don't matter much. The surface area of the contact patch will be very very close to exactly the same (assuming same tire pressure), and that's the whole ball game. A good rain tire helps at sub-hydroplaning speeds by channeling water away - perhaps a couple MPH higher hydroplaning in theory. But the problem with the hydroplaning speed is that's where water is acting less like a liquid (where it would flow out the tire's gaps) and more like a solid (where the speed simply doesn't give the water time to clear or move). As a result, the tire literally lifts off the pavement much like a typical planing motor boat's hull has s speed where the boat lifts up and begins planing on the water. As you've seen from the formula, it doesn't take much speed to hydroplane when you hit an inch deep water puddle - even on a heavy 4WD.

It helps to envision the contact patch at 61mph. It is covering 90 feet EVERY SECOND. That's why the "powered tire" TN was advocating doesn't matter - it's getting fed fresh untouched water at 90 ft/sec. Having said that, Audi did find that a driven tire's contact patch elongates in the direction of travel, reducing hydroplaning by a very small but measurable amount simply due to the change in shape - not (and I repeat NOT) because it was "clawing its way to the pavement". If you were in fact spinning the tires with power on water at freeway speeds, it's happening because you're hydroplaning - a bad thing, not a solution.

DougM