Visit our Popular Forums

J. Morgan · 01-29-2015, 10:06 AM

Why did they skew the HP and torque chart?

Top of the chart for HP is 400, and top of the chart for torque is 450,,,,

This might lead a person to think that charted torque and hp figures don't ALWAYS cross at 5252 RPM.

1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

dznf0g · 01-29-2015, 01:09 PM

Because the torque and horsepower don't rise at a one to one ratio at any given RPM. Something has to be skewed or you would have odd "dropouts in the line(s). If you want to represent a smooth RPM and torque line, then you have to skew one of the Y axis....or skew the x axis and have constant Y axis values.

This is me....not explaining very well.....where's someone with the proper math terminology?

J. Morgan · 01-29-2015, 02:45 PM

Traditionally, all of the graphs I remember seeing the HP and torque are on the same scale.

When I looked at that graph, and the lines did not cross at 5,252 RPM as they must on a one to one scale, I had to ask myself what was wrong with the graph. (Then I noticed the different scale)

Fwiw, torque and horsepower are always exactly the same at 5,252 RPM. This is dictated by the math.

Torque = twisting force only,

HP = amount of work that can be done in a specified period of time.

1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

scamp · 01-29-2015, 03:15 PM

Quote:

Originally Posted by tjdonahoe

Who wants to drive an engine at 5600 rpm to get the Max hp of 365 and 4100 rpm to get 383 lbs of torque??this is a going to the cafe to have coffee with the retirees engine.....

And get a 5 year 100,000.00 mile warrantee! Alright!

Don

dznf0g · 01-29-2015, 03:32 PM

We're really not disagreeing. But if you actually plotted the true datapoints on an equal scale, it would be a zig zag sort of a line. That is an attempt to show meaningful "curves" in relation to each other while maintaining as close to actual data points for each line individually (thus the skewed scale). The charts that show both on the same scale and have a nice smooth bell shape are gross averages of actual data points. Engine outputs are not a smooth constant line throughout their operating RPM range.

Notice that even with the skewed y axis, there are some angles in the slope of the curves. This is for accuracy...at any RPM you can see (more) actual individual torque values on the one y axis and (more) actual HP values on the other Y axis.

J. Morgan · 01-29-2015, 04:34 PM

Quote:

Originally Posted by scamp

And get a 5 year 100,000.00 mile warrantee! Alright!

Don

And beside this, what percentage of driving, even when towing does a person need full power?

1% of the time? I doubt it.

1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

phbarnhart · 01-29-2015, 04:48 PM

Engine power info for the 6.2:

Click Me

Same info for the 5.3:

Click Me, too!

These graphs are similarly skewed for some reason but they do a good job of demonstrating the flat torque curve of both engines. I can tell you that the 6.2 has phenomenal power the 8 speed transmission always finds the sweet spot.

rostam · 01-31-2015, 09:18 AM

Horsepower = (Torque x RPMs) / 5252

P.S. I don't own an Airstream and, hence, expect this to be challenged.

J. Morgan · 01-31-2015, 11:26 AM

Quote:

Originally Posted by rostam

Horsepower = (Torque x RPMs) / 5252

P.S. I don't own an Airstream and, hence, expect this to be challenged.

It wont be challenged by me, math is objective....

1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

white laker · 02-01-2015, 08:59 AM

So back to the original topic.......
Went to my local chev dealer and had a good look at the 6.2 combo in the 1500 ltz with lots of goodies. Nice truck. Ordered one to be built on March first. I currently haul my classic 31 with an '09 Yukon xl which does a great job, until I need to hit the hills. I was looking for a bit more without needing to go into a 3/4 ton diesel set up. I just didn't need that much truck for what I do 99.9 percent of the time. So this truck will show up with the max tow package with the 6 speed transmission, large diff and I believe a set of 3.42 gears. The package offerings are really confusing as they come from GM so we will see what shows. It should pull like a Billy Goat which will be fine for me. The truck will have all the rest of the trailer goodies as well, including a brake controller that I still may have to replace to run my disc brakes. In Fords lit it states that their controller will run "some" disc brake set ups. Do we know if they are compatable with Dexters?
So looking forward to the new truck in the spring. Really looking forward to the SPRING too.
Pete

lsbrodsky · 02-01-2015, 10:12 AM

I thought the 8 speed came with the 6.2?
Larry

dznf0g · 02-01-2015, 10:16 AM

Yeah, Pete, you'd better check into that. Doesn't make sense to me. Even the non-MaxTow are 8 speeds. And the order bank isn't open right now to 6.2L MaxTows with 8 speed.

A W Warn · 02-01-2015, 10:13 PM

Quote:

Originally Posted by white laker

So back to the original topic.......
Went to my local chev dealer and had a good look at the 6.2 combo in the 1500 ltz with lots of goodies. Nice truck. Ordered one to be built on March first. I currently haul my classic 31 with an '09 Yukon xl which does a great job, until I need to hit the hills. I was looking for a bit more without needing to go into a 3/4 ton diesel set up. I just didn't need that much truck for what I do 99.9 percent of the time. So this truck will show up with the max tow package with the 6 speed transmission, large diff and I believe a set of 3.42 gears. The package offerings are really confusing as they come from GM so we will see what shows. It should pull like a Billy Goat which will be fine for me. The truck will have all the rest of the trailer goodies as well, including a brake controller that I still may have to replace to run my disc brakes. In Fords lit it states that their controller will run "some" disc brake set ups. Do we know if they are compatable with Dexters?
So looking forward to the new truck in the spring. Really looking forward to the SPRING too.
Pete

You will be HAPPY with your new truck!!!!
Did you get the crew cab 4x4? If you did, I would like to know what payload capacity is on the door placard when you receive it.

ROBERTSUNRUS · 02-02-2015, 12:01 AM

Quote:

Originally Posted by rostam

Horsepower = (Torque x RPMs) / 5252

P.S. I don't own an Airstream and, hence, expect this to be challenged.

Hi, check out some recent articles in Hot Rod Magazine and this is exactly what you will see mentioned; Also check out the Dyno readings.

walker · 02-02-2015, 04:38 AM

Get what you want but I have had great success with RAM 1500 w 5.7 Hemi, 3.42 gear, 8 spd and the Air Ride is all four corners. To me it rode the best of all and stays level. Have used with Reese and Hensley. Reese was fine with this truck. Got the Hensley for my SUV that I like to tow with. I pull a 87 34'.

Sent from my iPhone using Airstream Forums

rostam · 02-02-2015, 07:25 AM

Quote:

Originally Posted by ROBERTSUNRUS

Hi, check out some recent articles in Hot Rod Magazine and this is exactly what you will see mentioned; Also check out the Dyno readings.

I knew this would get challenged

I bet the Dyno readings you refer to have different scales for HP and Torque. If they use the same scale, HP and Torque MUST match at 5252 RPM. And I would bet Hot Rod Magazine is wrong! Do you have a link to Hot Rod Magazine's article?

DC Bruce · 02-02-2015, 10:31 AM

Pete
Before you sign on the dotted line, you should be sure of what was ordered for you. At my insistence, the sales manager confirmed that GM is not accepting orders for the max trailer tow package with the 6.2 liter engine. However, you can order this with the 5.3 liter engine and perhaps this is what you're getting. The 5.3 does come with a 6-speed automatic, just like last year. Only the 6.2 comes with an 8-speed. The max trailer tow with the 8-speed does come with a 3.42 rear axle. I believe the 6-speed comes with a 3.73, because of its higher first gear.

white laker · 02-02-2015, 10:35 AM

The truck that I have coming is due in late March. It is the full 4 door, 4x4. Like I said the specs are really confusing when you look at the Max tow package. The NHT package states a 6 speed trans but it may be restricted to the 5.3 engine. The dodder entail ratio is also somewhat confusing as it looks like they warn to stay away from the big wheel when you get the 20" wheels. Like I said, this looks like the closest thing to what I am looking for. Will have to wait and see what arrives. Checked with the dealer and he can order the max tow with the 6.2 now, but I don't think he really has a handle on the order specs either.
Still have to deal with the better half over the colour.................. It never ends. I just want to hitch up and get out of the cold and snow!
Will let you know how I make out
Thanks to all
Pete

dznf0g · 02-02-2015, 10:48 AM

5.3 = 6 speed and 3.73 gears with maxtow
6.2 = 8 speed and 3.42 gears with maxtow

5.3 = 6 speed and 3.08 or 3.42 gears without maxtow
6.2 = 8 speed and 3.23 gears without maxtow

SteveH · 02-02-2015, 11:08 AM

Quote:

Originally Posted by dznf0g

5.3 = 6 speed and 3.73 gears with maxtow
6.2 = 8 speed and 3.42 gears with maxtow

5.3 = 6 speed and 3.08 or 3.42 gears without maxtow
6.2 = 8 speed and 3.23 gears without maxtow

Rich, Which configuration is your new truck, and how is it doing towing the trailer?