Almost all of my drivings from 500-1500'.

Its 500 pounds lighter. Not a whole lot, but it helps.

I wonder what elevation the V10s rated at?

 

A few years ago I replaced a spindle on a Dodge dually that a guy was using to run these hotshot loads all across the country. He asked me what kind of warranty came with my replacement and I told him that I guarantee it to be straight, the welds won't break anf the spindle won't pull out of the housing. But, as soon as you hook to anything that requires half of what you have this truck licensed for, forget it. Guarantee is void. He had a 60,000lb tag on a 1 ton dodge dually. He said the truck would pull it. I said, no, the engine would. The rest of the truck won't, otherwise I wouldn't be here replacing this spindle that you damaged when you snapped the axle shaft. I told him hauling this much weight you need a semi tractor. If one tons were meant to pull that kind of weight, a lot of semi trucks could be grounded.

 

Performance numbers are marketing numbers. I would be shocked if they weren't either tested at sea level or the numbers have been calculated to be equivalent to sea level. With the way the industry tries to out do one another on hp and torque, I can't see any way that Ford or any other manufacturer would publish anything other than best case. If I were them, I'd publish Death Valley numbers on a cold day in January with a high pressure system sitting overhead.

 

Yeah sorry.....it was the Air Force and the F-22 Raptor which uses Diesel...well JP-8 which is a "type" of Diesel. hahhah

 

Yeah, I thought they use JP8 in their jets too. JP8 was suppose to be a universal fuel for the military. Again though, the military has no problem replacing fuel injectors, or entire engines for that matter, every 50,000 miles on the tax payer dollar.

If I remember right JP8 is a kerosene blend of some sort though. That makes it more like the diesel trucks are running jet fuel, not jets are running diesel fuel. After all JP stand for Jet Propellent.

Hey: wiki eve has JP8! That surprises me. Interesting they note how the stuff sticks to everything. It really is nasty stuff to work with.
JP-8 - Wikipedia, the free encyclopedia

 

Yeah, alltitude hurts engine performance for sure.

As for a turbo, you bet it affects them too. The 7.3 will be hurt the most because the 6.0, 6.4, and 6.7 have variable veins which can help minimize loses, the 7.3 does not. But overall a turbo will still feel it no matter what. Even the variable vein turbos have to have a faster sindle and axel speed to keep up. I am not sure of the % loss, I would GUESS the 7.3 would feel a 2% where as new tech migh be closer to 1%, but those are just guesses. You would have to pull out the compressor maps to see for sure, and I don't have one for the 7.3's turbo.

 

They probably do it in a pressure chamber

 

Thats really messed up. God forbid he wrecks and kills someone. At least the victim's family will have his house, his wrecked truck and everything else he owns. I would imagine that truck had a hell of a time getting that rig to a stopped.

 

JP-8 has been used in the Air Force since the early 90's. It may be nasty stuff, but it's nothing compared to JP-4, which it replaced. JP-4 was very volatile and had major issues with static buildup during refueling.

The only injector issues I remember having were related to the afterburner, not the hot section of the engine. I do remember engines getting swapped out relatively frequently, as compared to civil aviation, but that was not necessarily due to injectors. You run any engine through what those engines go through and you have to pull them and inspect them. After all, you're talking about a $3 mil plus asset, per engine. It's not a $7,000 dollar option with a turbo.

A 7.3 should not lose any performance up to a certain elevation. Even the stock turbo has excess capacity. It uses a waste gate to relieve the excess pressure. As you go up in elevation, the excess capacity reduces to zero. At that point, the truck will start losing performance with elevation gains just like trucks with N/A engines do.

A 6.0 and 6.4 both have the variable vanes that not only make the turbo more efficient, but the keep the turbo from overboosting the engine. At some point, just like a waste gated turbo, there will be no excess capacity. As long as a turbo has the capability to get too much energy from the turbine than the engine can handle, the engine will enjoy the same performance as if it was at sea level.

I have heard numbers from 7,000 to 11,000, meaning that a psd will enjoy sea level performance up to those elevations. I'm just curious where the truth lies for each particular engine. Of course, the possibility exists that I could be completely wrong.

 

Thats were the commercial registration and insurance come in.
With both of thoes its perfectly legal and an accident will be covered.

With trailer brakes it should stop ok. I would much rather have air brakes at that kind of weight though.

 

By nasty I mean you get JP8 on you and never comes off.

The 7.3 has excess capacity in the turbo, but that doesn't matter unless you retune the entire engine compressor map for that specific alittude. The turbo will bring a certain volume of air and compres it. If that volume of air is less dense, there will be less oxygen in that volume of air. Less oxygen to the engine means lower performance. You could connect a boost controller and crank up the boost to compinsate for the lower atmospheric pressure, but that's a different story. But also remember, to much extra capacity and you get lag, so it won't be enourmous. The turbo set up will also not loose power as bad as N/A's will. I forget all reasoning behind it, and I'm about to leave on a weekend trip, so I don't have time to look it up, but I remember turbo don't loose as bad as N/A.

For a clearer picture of what I'm talking about just google airplane, turbo, and altitude, there are tons of information about boost at altitude. I wil grant you that the turbo and wastgate can probably handle a certain amount of elivation without power loss, my guess would be 5,000-6,000 feet or so since most of the US is below that and very few people will be using max power above that. But I can guarentee the all engines will suffer at 11,000 ft.

even if the engine is designed to operate at 11,000 ft, compared to sea level to will not make as much power. Think of it this way, at elivation you have to work far harder to cram the same amount of oxygen into the the same area because the air is less dense right? The extra compression isn't free, energy for that has to come from somewhere, and that some where is from the overall power produced. It can manifest it's self in many places, exshaust back pressure, lower boost, etc., or any combination of those but it is there somewhere. Technology has come a long way in minizing the effects of alititude, but there is no way around the simple physics that you have to work hard to get the same amount of boot when the air is less dense.

Any concept that boosted car/truck engines don't suffer at altitude like that is nothing more than wishful thinking. Take a dyno up there and prove me wrong lol.

 

That's probably one of the reasons why PA registration goes by the manufacturer's GVWR and GCWR and not by any weight you want.

 

He wanted to keep debating me about how his truck would pull his trailer, and I finally called him a effin idiot. And I meant it! One of the few times I ever called a paying customer a effin idiot to their face.

 

I would have done the same.

With that weight he was about tripleing the rated GCWR of the truck. That is gross neglegence in my book. A good attorney will make shure he never sees the road again whether he has insurance or not.

The brakes would stop the truck eventually, but in what distance. Throw some hills in there and the brakes can be toast before you know it.

The way it should be IMO.

 

When I FLOOR my truck (2009 6.4 PSD) it shifts a little past 4000 RPM's. Are you now saying the V10 redline is 8000 RPM's +? Hell, in tow/haul it shifts above 3k without standing on the gas.