M923A2 Doing 80 MPH!!

[Csm Davis]

So that most of you know the speed rating has more to do with the load capacity of the tire. The 4 things involved in affecting tire life are Load, Air pressure, Speed, & Duration. You can change any one of those variables by altering the others. For example a XZL mich 1600R20 max load is 14540lbs @ 110psi @ 55mph @ sustained duration

Those tires at 120psi @ 25mph @ 2hours run time will yeild MUCH greater load capacity because we changed the charicteristics of the equasion.

Right or wrong this guy likley had fully inflated tires on an empty truck driving faster for a short period of time.

Tires blow due to heat buildup. The above equation is essentailly a HEAT buildup rating. Many of the tires that people on here have blow up are due to 1 the equation, and 2 age of the tire. An older tire cannot work at the same capacity as a new one. HOWEVER i am currently running 35 year old tires on my Jeep. I run them at max air pressure, slow speeds and short distances. They are ugly, weather cracked, and some would say dangerous... I however understand the limitations of these tires so i dont take them down the freeway for more than a mile or 2, and the load on the tires is HALF of what they are rated for.

This is not the primary reason for the speed restrictions on these tires, the centrifugal, or how ever you spell it, forces are a major reason they are restricted in speed. And if you are running 120 psi in a 14.00 you are way over pressure on the stock 939 rims and are just as bad as the guy running 80 mph. Maximum pressure on the rims are 85 psi.

 

[MuleMac01]

https://youtu.be/xEF0PV3kAx8

 

[spicergear]

The M939 series is a comfortable truck to drive compared to the deuces or 800 series. 50mph is easy, and feels like you're loafing along. It's big, drives well, and oozes confidence which is good if you're in touch with driving well and knowing what you have...bad if you got it and think it's a deuce size truck or decide to drive it like you stole it.

 

[Suprman]

It's not like the mil trucks are the only oversize vehicles people push the limits in. I see triaxle dumps and other heavy haulers flyng down the highway all the time. In my civ car if traffic is flowing at 80 in the number one lane I have no problem crusin along. I can't tell you how many times a big truck or semi will pass on the right.

 

[Special T]

This is not the primary reason for the speed restrictions on these tires, the centrifugal, or how ever you spell it, forces are a major reason they are restricted in speed. And if you are running 120 psi in a 14.00 you are way over pressure on the stock 939 rims and are just as bad as the guy running 80 mph. Maximum pressure on the rims are 85 psi.

I dont think what the driver was doing was Smart, Prudent, or Safe.

I understand the point about the wheels, and you are correct. I only pointed out the example because i know of 1600R20's in industrial/ AG use on different wheels in the exact situation I described.

Tires that come apart via seperation or centerfusial force to not "Blow out". The tread comes off the casing and the casing still holds air... Until you wear out the steel belt from braking or driving. One example of misuse of a tire rating is this. I had relaced one tire on my trailer for a trip. it was the same make/size design ect as the others but was a load range C instead of D. (on accident) Since i was loaded to capacity, and doing 60mph for about an hour the LR C tire seperated and the tread came off. The tire still held air and i was able to change it out with my spare.(letting the air out of the tire before doing so).

Part of the additional reason why centrifugal force may NOT have been an issue has to do with how much tread is on the tire. I belive the tires come with 35ish 32nds if the tread depth is much less than that the force would not be so great.

 

[drivebymashing]

I wish my deuce would do 80 at least it could cruise at 65mph comfortably.

 

[steelandcanvas]

I wish my deuce would do 80 at least it could cruise at 65mph comfortably.

Then you probably have invested in the wrong vehicle.

 

[turnkey]

It is the chase truck for the new movie, Fast and OMG 8......They are going to drift the MV at 75 and see what happens..It is going to have a disel in it. Not sure which one???

 

[turnkey]

Nice video...It doesn't cover backseat drivers....

 

[drivebymashing]

Then you probably have invested in the wrong vehicle.

No i invested in the right vehicle. Ive had 35 vehicles. I know what I bought. Cant a man dream?

 

[Sardo67]

https://youtu.be/xEF0PV3kAx8

Ummmmmmm. Wtf?

 

[porkysplace]

If your truck shakes over 50mph, something is wrong.

The guy going 80mph obviously has his fuel and governor turned up. He's exceeding the tire rating and speed limit, but he'll get caught and slow down, or have his insurance cancelled.

Anybody ever consider this is why insurance companies refuse to insure MV's , you really can't blame them with idiots like this.

 

[Sardo67]

It's because they're massive large and usually old rigs that if ever in an accident will mess things up along with 0 things for crash safety than maybe a lap belt. Also it's typically something with air brakes or needing a CDL to operate but depending on how it's registered the operator may be able to get around needing the CDL.


How how many of these are in accidents a year anyway? I would guess these are on the same level to insure as a tri-axle dump truck no?

 

[rhurey]

The dump truck is usually an asset where the owner isn't making money if the wheels aren't turning.

 

[red]

I wish my deuce would do 80 at least it could cruise at 65mph comfortably.

You can safely get a deuce cruising at 65mph. Brakes, tires, power steering, and overdrive upgrades are required.

 

[DavidWymore]

So that most of you know the speed rating has more to do with the load capacity of the tire. The 4 things involved in affecting tire life are Load, Air pressure, Speed, & Duration. You can change any one of those variables by altering the others. For example a XZL mich 1600R20 max load is 14540lbs @ 110psi @ 55mph @ sustained duration

Those tires at 120psi @ 25mph @ 2hours run time will yeild MUCH greater load capacity because we changed the charicteristics of the equasion.

Right or wrong this guy likley had fully inflated tires on an empty truck driving faster for a short period of time.

Tires blow due to heat buildup. The above equation is essentailly a HEAT buildup rating. Many of the tires that people on here have blow up are due to 1 the equation, and 2 age of the tire. An older tire cannot work at the same capacity as a new one.

That's what I was gonna say. They blow due to heat buildup due to sidewall flex. Lots of air, no load, no flex, minimal heat. Course the front is always heavy, so the fronts will always have some flex.

I'd go 80 in a 900 series, not in traffic and whatnot though. It's one thing to endanger yourself and another everyone else.

 

[Wildchild467]

With one or two clicks of the gov springs an A2 truck will easily go 80mph. I don't advise it though. The 6cta motor is military goverened at around 2100 rpms but with minor mods it will happily rev well over 3k. At 2100 rpms you can do around 70mph. You will kill your ctis hub seals going fast though.

How does speed effect the hub seals? I am not sure I understand the connection. I don't know anything about the CTIS hub seals. Thank you.

 

[Floridianson]

It has nothing to do with new tires, motors, brakes or anything you think you did to make yourself believe the truck should go faster. It's our bumper is to high. We will walk over top of or the walkover causes us to leave our lane and maybe even flip the truck over. Could even leave our lane and involve another car too. A bumper that is say 20 inches off the ground pushes the other poor guy who knows where but it pushes it out of our way and for the most part we stay in our lane and if luck is on your side you come to a stop with just dirty tidy white's

 

[Alexsha]

Because I'm a smart ass here, I'm just going to add this:

It's not centrifugal, it's centripetal. Centripetal force is a force. Centrifugal "force" is not a force, but a feeling that results from centripetal force.

 

[patracy]

No i invested in the right vehicle. Ive had 35 vehicles. I know what I bought. Cant a man dream?

Sometimes dreams turn into nightmares...

Kind of like this thread.