F550 Chassis Super C power ratings

Also Ford is quick to cancel your warranty on your diesel if you re-program it for more power. Pretty risky since it's $12-20,000 when the fuel pump goes out on the 6.7L. Plenty of information on both topics on the Ford diesel forums, and also good info on the fuel pump in the Tow Vehicles section.

tatest wrote:

McKenziek wrote:
the claimed GCW is 19000 and the GCVW is 35000. Would it be possible to re-tune or even advisable?

It is almost always possible to retune, although some parts swaps may be required, I don't know the details for the various versions of the PowerStroke. I know a lot about bringing 160-250 HP CTDs up to the 300-350 HP level, and a little about building those for drag racing and tractor pulls.

I don't consider it advisable, the whole point of having different engine ratings for different duty cycles is to meet customer expectations of service and longevity. In the search for more power, where do you stop? More important, how do you plan to use the extra power? To tow a heavier load, or to just cut a couple seconds off your acceleration to freeway speed?

Unless you already have a racing engine with an expected life of a few hours or less, you can always up the ante, especially with supercharging and computerized engine controls. A 600 HP 6.7 Powerstroke is not much of a reach, but it is not going to put out that kind of power for 250,000 miles.

Look at it this way. The last of the piston engines for large aircraft had takeoff ratings of 3000+ horsepower. They could sustain that for something like two minutes to ten minutes before immediate self-destruction. Same engine might be 2200 horsepower maximum sustainable, good for a couple hundred hours. Cruise power might be 1600-1800, 300-500 hours. They needed flight engineers managing the engines and logging times and power settings, to optimize engine life, and determine when to rebuild. What you had was a 2200 HP engine with a 140% power setting for takeoff. The extreme cases were about 180% power.

Modern computer controlled engines have, in the pickup truck versions, the equivalent of takeoff power. The marketing department demands this. But the computer engine management goes only so far as to avoid the immediate self-destruction. Although it may be logging other uses of power, it is not set up to tell you "engine life nn%" or predict " nnnn hours before overhaul."

So what you get in a truck that might need to put out 100% power 100% of time, is an engine limited to 100% power. You don't get the 150% output setting provided as a sales tool for the F-250.

Well said. Thank you

McKenziek wrote:
the claimed GCW is 19000 and the GCVW is 35000. Would it be possible to re-tune or even advisable?

It is almost always possible to retune, although some parts swaps may be required, I don't know the details for the various versions of the PowerStroke. I know a lot about bringing 160-250 HP CTDs up to the 300-350 HP level, and a little about building those for drag racing and tractor pulls.

I don't consider it advisable, the whole point of having different engine ratings for different duty cycles is to meet customer expectations of service and longevity. In the search for more power, where do you stop? More important, how do you plan to use the extra power? To tow a heavier load, or to just cut a couple seconds off your acceleration to freeway speed?

Unless you already have a racing engine with an expected life of a few hours or less, you can always up the ante, especially with supercharging and computerized engine controls. A 600 HP 6.7 Powerstroke is not much of a reach, but it is not going to put out that kind of power for 250,000 miles.

Look at it this way. The last of the piston engines for large aircraft had takeoff ratings of 3000+ horsepower. They could sustain that for something like two minutes to ten minutes before immediate self-destruction. Same engine might be 2200 horsepower maximum sustainable, good for a couple hundred hours. Cruise power might be 1600-1800, 300-500 hours. They needed flight engineers managing the engines and logging times and power settings, to optimize engine life, and determine when to rebuild. What you had was a 2200 HP engine with a 140% power setting for takeoff. The extreme cases were about 180% power.

Modern computer controlled engines have, in the pickup truck versions, the equivalent of takeoff power. The marketing department demands this. But the computer engine management goes only so far as to avoid the immediate self-destruction. Although it may be logging other uses of power, it is not set up to tell you "engine life nn%" or predict " nnnn hours before overhaul."

So what you get in a truck that might need to put out 100% power 100% of time, is an engine limited to 100% power. You don't get the 150% output setting provided as a sales tool for the F-250.

the claimed GCW is 19000 and the GCVW is 35000. Would it be possible to re-tune or even advisable?

Almost every turbodiesel shared between pickup trucks and medium-duty trucks gets de-tuned to a sustainable output for the MDT application, and rated for 100% duty cycle.

Ford and Freightliner were doing the same when using Cummins and Cat engines in their MDTs. Ratings were even below the engine offerings for bare motorhome chassis, which is considered light-duty compared to medium duty truck applications.

Pickups get something more like a "peak horsepower" rating usable for short bursts of power, with the computer watching things and cutting back to sustainable outputs when necessary to save the engine. Those ratings are for marketing, there is a horsepower race in the pickup sales business, like those 400-425 horsepower V8s in 1960's muscle cars. Dragstrip horsepower.

Yes, that is the problem. Ford has lower output on the F-450 and F-550 cab and chassis engines, and also has a significantly higher rear axle ratio, so the engine is spinning faster for a given road speed.

But you should be able to tow a really large trailer with the F-550. It can be had in 17,500 and 19,000 GVWR last time I checked. Crewcab might not offer the highest GVWR though.

Fred.

Ford only offer the high power rating in pickups. All cab/chassis are detuned due to duty-cycle demands.