7.3L HP/TQ: stock & with tunes

[cleatus12r]

The following two shots are the torque curves for each. The diesel graph was emulated from an existing 400 HP dyno run while the gasoline graph was transcribed from Desktop Dyno software. Again, the diesel is on the left and the gasoline engine is on the right. Don't get too bent out of shape as to what seems to be a much flatter, more broad torque curve on the gas engine because the RPM axis covers twice the ground and it affects the way the curve appears.

[cleatus12r]

The bread and butter.....

0-60 times. The times and 60 MPH speed are shown in the upper left hand corner of the graphs.

[cleatus12r]

As you have realized, there is no reason to EVER build a full-on gasoline engine to tow with. Sure, it will kick the crap out of a diesel with similar torque numbers, but it's going to use 35 gallons of gasoline to feed 6000 RPM all the way up a 4-mile ascent.....if the engine even lives that long.

I don't hate diesels. I love them. I love my Powerstrokes. However, when people ask me how much torque they will get and that horsepower doesn't matter, I just give them the option to double the advertised horsepower rating....and be mindful of where the torque peak will be in the RPM range.

I think your dyno is a bit off. Your rear-wheel torque reading on a 100 HP tune should be in the neighborhood of 600 ft. lbs. Most stockers will run in the vicinity of 200 HP and 420 Ft. lbs. at the rear wheels.

[cleatus12r]

As a matter of fact, out of pure curiosity, I made a few different calculations and found that the 521, if only allowed to make 680 ft. lbs. at a similar RPM would only then just be on par with the 920 ft. lb. Powerstroke in terms of acceleration.

Gearing is where it's at and torque multiplication THROUGH gearing means that higher average horsepower will win every time (just not from a durability standpoint).

[turbosuzuki]

WOW im really lost now then, all this time i thought that the diesels torque was what it was all about, well that sucks. Nice write up though

[dietoremain]

Originally Posted by turbosuzuki

WOW im really lost now then, all this time i thought that the diesels torque was what it was all about, well that sucks. Nice write up though

He explained it very well.. But torque is a product of power band and diesels have a much BETTER power band than a gasser any day(more work in less RPM) and that is why they put down so much 'torque.' That is why you wont see gassers with a torque # double that or more of HP... and of course why gassers arent big tow rigs, they suck, literally lol..

Hope that helps too.

[cleatus12r]

Originally Posted by dietoremain

But torque is a product of power band

Torque is a product of volumetric efficiency.

Originally Posted by dietoremain

and diesels have a much BETTER power band than a gasser any day(more work in less RPM) and that is why they put down so much 'torque.'

Torque is the product of compression and diesel fuel burning characteristics. Also, the term "better powerband" is not really accurate.

Originally Posted by dietoremain

of course why gassers arent big tow rigs, they suck, literally lol..

Gassers make great tow rigs. However, at the RPM that most of them would be required to run to put the most power to the pavement, they don't lend themselves well to being fuel efficient.
Remember, not every trailer is required to be pulled in a competitive environment either.