That's why they shoot up Vail Pass...In the truck lane...with their flashers on. They can't stay at WOT too long.

 

This had NOTHING to do with the engine. It is 100% a transmission logic to keep the temps down. I believe the same logic exist for the 7.3/4R100 combo.

 

They can run at WOT just fine, for any amount of time.

 

Correct. This is NOT an engine "safegaurd". It was purely for the transmission and transmission only!

 

Tom drives a 6.4 doesn't he? Or does he drive someone elses vehicle in the test?

 

Well then I'll default to my previous statement that goes like this: "They have no *****".

Actually, what you're saying is that they can run at WOT all day...if the transmission says it's ok...

 

Although I own a V10 (by choice, not accident) I regularly drive the '09 6.4 F250 regular cab short bed we have at work. While it's certainly a nice truck, it's in no way a match for the 6.7 Cummins in my Dad's '07 Dodge. It actually feels a lot like my V10 except it gets worse mileage. Now the question to you is, ever drive a V10?

 

I drove Tom's truck (the white 6.4) and Tom drove my truck (the V10) all four times in the videos.

 

They can run full throttle all day either way.
It just changes the RPM that it runs at.

 

Tom drives a 6.4 but he was in Matt's 6.0 when he was calling out the 31....32.....33....34.... They were testing a 6.0, 7.3, 6.4 and v10 on that day.

 

Yes, we had several of them as TMP vehicles when I was in the Army

 

It's a 4R100 logic only that would effect a diesel the same as gas engine that locks the TC up after certain parameters are meet. I don't think it's a "safeguard" per say. It's simple programing logic. I highly doubt Ford though about starting a 18K+ load out on a 15% grade. They just took some parameters and said this plus that should be "good enough".

 

What year V10?

 

Actually, that would probably have more to do with the way that the transmission will hold the gearing lower when grunting than when not towing weight. A spike of 3,000RPMs may show say 7 psi. while a sustained 3,000 might show 15. This is due to the turbo pressurizing the engine with boost, which increases up to a point consistently.

Thing is that I have heard about horsepower in the thread about a thousand times, but torque is not discussed. Our 1999 Kubota L3010 only has something like 23hp, but would pull trailers and stumps as much as we could load it down. Torque is much more important in towing than horsepower. Tractor trailers used to have a fairly close gas/diesel ratio, but almost all on the road today are diesels. This change over happened back before diesel was more expensive than gasoline, too.

 

If anything you're saying with more load the Diesels will put out LESS power once the EGTs get up. The computer wasn't limiting the engine speed. It was trying to protect the transmission by locking the torque converter up. A locked up converter generates a lot less heat then an unlocked. I guess Ford was worried that the "wimpy" V10 can burn up the same transmission used behind the 7.3.....

As far as a 6.4 not hitting full boost unless towing/hauling, that is probably the result of the engine programming meant to help improve mileage. It won't fully fuel the engine unless it calculates a heavy load. Older Diesels will happily hit full boost unloaded. So if you don't hit full boost unloaded, that means you are not making your full 350HP either But anyways the difference between hauling 10,000 lbs and 12,000 lbs is not going to make the engine boost any higher.

As far as having a lot of torque, yes that is important for a pleasant towing experience. It means your engine can put out more horsepower at a lower RPM. Less downshifts, etc..You could have a 650 ft-lb engine 15HP engine, lots and lots of torque and can get any load moving but when it comes down to it, it can only do 15HP work of work. Your top speed will be extremely low and going up any hill will require you to downshift until you are barely moving. The same thing with my 12HP IH Cub Cadet. The near infinite ratios of the hydro transmission lets this 700 lb 12HP tractor pull my 3200 lb ranger just barely up to the tractors max speed of 8MPH, and at that speed pulling the truck the engine's governor has the throttle plate on the carb wide open.

Has anyone here actually been in a semi before? I have. I was in one with a trailer full of scrap foam, not exactly a heavy load and even then acceleration was a joke. Even though this engine had well in excess of 1200 lb-ft of torque, its 350-400HP is what ultimately limited its acceleration and top speed. We were going about 60, and I asked my buddy driving if the pedal was to the floor - and he replied with a yes, and that was after we unloaded all the scrap foam too. Any hill meant a downshift or 4 and a dramatic reduction in speed.