Big Three road tests

[BlackSilver]

Found this review on line, of the three heavy duty pickups.

[buddyIam]

I found it. The 68RFE is:
3.27
1.84
1.41
1.00
.82
.63
reverse is 4.44

[buddyIam]

No, the ford has the most power, the ram the most torque in the high horsepower version. But ford was also higher in torque than the ram that was tested

Boy, Alison sure takes a big jump from 1st to 2nd

Wonder what the gears are in the tansmission the ram was tested with. The one in the truck they tested was the 6-Speed Automatic 68RFE Transmission.

[Turtle_n_Peeps]

Something seems amiss. First the fact that there was a quarter mile test. And then looking at the results, the two with the highest power ratings score near equal times. Yet the Lowest rated truck bests the other two by 3/4 second empty and .9 seconds loaded

Then why do you think something is amiss? The Chevy had the most "power" and won going up hill. Ford is overrated (as I said in my first post) and many tests have proven it.

BTW the Allison has a:

3.10 1st gear.
1.81 2nd gear.
1.41 33rd gear.
1.00 4th gear.
0.71 5th gear.
0.61 6th gear.

The Aisin has a:

3.75 1st gear.
2.00 2nd gear.
1.34 3rd gear.
1.00 4th gear.
0.74 5th gear.
0.63 6th gear.

Both in the test had 3.73 rear. So much for the gear advantage. :E

[buddyIam]

Turtle

You just made my argument. Go to the point on the chart where the PRODUCT of RPM, times torque, is the greatest.

For this chart it is about 3200 RPM just like you said. Torque dropped off slowly up until that point, but the rise in RPM meant the product of RPM and torque continued to increase.

If torque only drops slowly as RPM increases. POWER goes up. Because POWER is the product of RPM and Torque.

You notice I don't argue with the term power. Just HP. That is because HP is only a salesman pitch.

For instance, tell me the size of the horses Watt used to come up with his constant of 5252? Were they Shetland Pony's or Clydesdales?

It's fine to compare an engine using Power as long as you understand that power is just a product of torque and RPM.

HP=RPM*torque/5252

[Turtle_n_Peeps]

I will say this again. A engine makes it's greatest power at the point of a graph where the product of Torque and rpm is the greatest.

You can say it all you want but it's still totally wrong.



Look at this chart. Lets look at the Dmax (yellow line). It makes the most torque around 1600 RPM. The Dmax does not make it's most power at 1600 RPM. It makes it around 3200.

[Turtle_n_Peeps]

buddyIam wrote:
Basically HP is acceleration, torque is twisting power, Your highest HP will be at the point of a curve where the product of RPM and torque is the greatest.

A dyno can not measure HP. It only measures torque and RPM.

Torque times rpm equals power. To compare that to a real horses power you have to divide by the constant 5252.

To rate yourself in elephant power you would have to make an estimate of how much power a elephant makes, make the calculations the same as Watt did, and replace the 5252 constant with your new elephant constant.

The 5252 number is not exact. It's just a number that is used in all HP calculations. It was a steam engine salesman's pitch to sell steam engines.

And that is why the Cummins with almost 100 more ft of torque got waxed towing up a hill and at the drag strip. The Chevy put out more HP so it was faster up the hill.

Nothing amiss at all. The math works. The Chevy had the most HP and beat the Ram up the hill.

[RCMAN46]

buddyIam wrote:


A dyno can not measure HP. It only measures torque and RPM.

.

Look up what a chassis dynamometer is and how it works. This is the most common dynamometer you will find used in the field.

It does not and can not measure torque directly. The torque is calculated.

[buddyIam]

Turtle

If you are making 1000 ft lbs of torque at 100 rpm you are making 19.04 HP.

If you could make that RPM 2000 and the same 1000Ft lbs you would be at 380 HP on your bicycle. You would most certainly need to have a system of torque management for your peddles.

I will say this again. A engine makes it's greatest power at the point of a graph where the product of Torque and rpm is the greatest.

You can not measure HP. It is only a mathematical equation. A sales pitch.

[buddyIam]

Basically HP is acceleration, torque is twisting power, Your highest HP will be at the point of a curve where the product of RPM and torque is the greatest.

A dyno can not measure HP. It only measures torque and RPM.

Torque times rpm equals power. To compare that to a real horses power you have to divide by the constant 5252.

To rate yourself in elephant power you would have to make an estimate of how much power a elephant makes, make the calculations the same as Watt did, and replace the 5252 constant with your new elephant constant.

The 5252 number is not exact. It's just a number that is used in all HP calculations. It was a steam engine salesman's pitch to sell steam engines.

[Turtle_n_Peeps]

Sport45 wrote:

buddyIam wrote:
Turtle

For the last time Torgue creates HP. 😄

Link

Right, torque is measured and HP is calculated from it based on rpm. (I'm not quite sure what torgue does. :))

So HP is the indication of how fast the engine can apply torque. A high torque engine will get the load to the top of a hill without doubt. To get to the top faster all you have to do is increase the HP. 😉

At least someone gets it! :B

BuddyIam I can make around 200 ft/lbs of torque when I get on a bicycle. (over a 1000 ft/lbs though gear reduction)But only about a 1/2 HP. Think I would make a good towing engine? After all, I can make more torque than a Cummins! :B

[buddyIam]

sport45,

Basically HP is acceleration, torque is twisting power, Your highest HP will be at the point of a curve where the product of RPM and torque is the greatest.

A dyno can not measure HP. It only measures torque and RPM.

Torque times rpm equals power. To compare that to HP you have to divide by the constant 5252.

To rate yourself in elephant power you would have to make an estimate of how much power a elephant makes, make the calculations the same as Watt did, and replace the 5252 constant with your new elephant constant.

The 5252 number is not exact. It's just a number that is used in all HP calculations. It was a steam engine salesman's pitch to sell steam engines. 😄

[buddyIam]

rjstractor,

You brought up my dilemma. I sure would like the manual for the exhaust brake coming down steep 2 lane mountain roads. Coming down hill I run into a great many 10 mph hairpin turns up in the Sierras. Giving up the power to get it burns my butt. :B

To get out of the valley were I live there is a good amount of steep interstate grades. It sure would be nice to have the extra power for those.

I always end up thinking safety on the steep mountain downhill should be my priority.

But that limits me to only the Ram. Even worse power in the 4500's and 5500's.

[Sport45]

buddyIam wrote:
Turtle

For the last time Torgue creates HP. 😄

Link

Right, torque is measured and HP is calculated from it based on rpm. (I'm not quite sure what torgue does. :))

So HP is the indication of how fast the engine can apply torque. A high torque engine will get the load to the top of a hill without doubt. To get to the top faster all you have to do is increase the HP. 😉

[rjstractor]

buddylam wrote:

The difference in HP could be the result of higher RPM of a very small amount.

Now if the Alison first gear was very low compared to the Ford and Ram. The DMAX would create a great deal of torque in first gear that might lead to a initial lead that might be insurmountable within a 1/4 mile.

I'll say it a different way. Something stinks.

Either the tests are faulty.
The Dmax is under rated.
The Ford and Ram are over rated.

None of the 3 above have anything to do with my sisters or hookers.

It appears the customer is being deceived in some form. That is what concerns me.

Something that no doubt is a factor is torque management. I don't know how exactly the computers manage it, but you can almost guarantee that none of those trucks have full torque available in first gear. If they did they would need huge driveshafts and axles to avoid drivetrain damage at the hands of a driver lacking common sense. I imagine that is why the Ram Cummins with a 6 speed manual is derated quite a bit from automatic models. I'll bet a software change or two could up the hp and torque to the same as an automatic, but the driver would have to have brains enough to not drop the hammer in low gear with a 20K trailer in tow!

[buddyIam]

Turtle

For the last time Torgue creates HP. 😄

Link