torque

Thread Tools
 
Search this Thread
 
  #1  
Old 10-11-2011, 05:18 AM
dnunez3418's Avatar
dnunez3418
dnunez3418 is offline
New User
Thread Starter
Join Date: May 2011
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
torque

Ok so I have an 83hour f-250 with a 460. It is coupled with a c6 auto 3speed tranny. I know what the motor is rated at out of the crate and I know what the tranny is rated at as well. What I wanna know is if there is some way without dynoing I can find out how much my truck is puttin out at the wheels. Torque and hp. Any help would be appreciated and I know without a dyno it'll just be a give or take estimate. This is just for personal knowledge..........for now. Thanks
 
  #2  
Old 10-11-2011, 09:17 AM
85e150's Avatar
85e150
85e150 is online now
Super Moderator
Join Date: Apr 2004
Posts: 31,869
Received 1,591 Likes on 1,296 Posts
If it's a stocker, save yourself time and money and figure maybe 80% of what is published.

Or go to this place:

The Dyno Edge

Don't know where you're at, could be around the corner or it might take you all day to get there.
 
  #3  
Old 10-11-2011, 09:40 AM
dnunez3418's Avatar
dnunez3418
dnunez3418 is offline
New User
Thread Starter
Join Date: May 2011
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by 85e150six4mtod
If it's a stocker, save yourself time and money and figure maybe 80% of what is published.

Or go to this place:

The Dyno Edge

Don't know where you're at, could be around the corner or it might take you all day to get there.
So does that mean it would be the combined hp and torque of both motor and tranny or just the motor.
 
  #4  
Old 10-11-2011, 02:57 PM
85e150's Avatar
85e150
85e150 is online now
Super Moderator
Join Date: Apr 2004
Posts: 31,869
Received 1,591 Likes on 1,296 Posts
The engine produces torque. Via the TC and gear reduction, the trans multiplies this torque to make the vehicle move. In the process, some power goes up in heat due to the friction in the trans, axle, u-joint etc.

So the net engine torque to reach the rear wheels is roughly figured at 80% of the flywheel torque figure.
 
  #5  
Old 10-11-2011, 05:05 PM
Beechkid's Avatar
Beechkid
Beechkid is offline
Moderator
Join Date: Aug 2002
Location: Southern California
Posts: 5,776
Received 210 Likes on 160 Posts
In general, automatic trans typically suck up about 30 hp
 
  #6  
Old 10-12-2011, 11:28 AM
Bear 45/70's Avatar
Bear 45/70
Bear 45/70 is offline
Post Fiend
Join Date: Mar 2004
Location: Union, Washington
Posts: 6,056
Likes: 0
Received 6 Likes on 6 Posts
Depends on what gear you are in, because torque is multiplied by gearing while horsepower is not.

200 ft/lbs with a 4.10 rear gear with trans in high = 820 ft/lbs

200 ft/lbs with same rear gear but in first gear (2.46) = 2017 ft/lbs
 
  #7  
Old 10-14-2011, 02:30 PM
jokerforever's Avatar
jokerforever
jokerforever is offline
Elder User
Join Date: Jun 2005
Posts: 817
Likes: 0
Received 1 Like on 1 Post
They would be very rough numbers and would only be peak but you could take the truck to a drag strip and run it a few times, take your time, trap speed, plus weight of the truck and plug them into any of the HP calculators available online. Again, these wouldn't be exact but would give you a baseline and something to bench race with.
 
  #8  
Old 10-15-2011, 12:08 AM
85e150's Avatar
85e150
85e150 is online now
Super Moderator
Join Date: Apr 2004
Posts: 31,869
Received 1,591 Likes on 1,296 Posts
I take it this is a stock truck, so the OP knows the factory flywheel numbers and can figure the approximate RWHP without doing anything other than multiplying that flywheel number by .80.

IMO, OP is looking for something that isn't there.
 
  #9  
Old 10-24-2011, 09:10 PM
dnunez3418's Avatar
dnunez3418
dnunez3418 is offline
New User
Thread Starter
Join Date: May 2011
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
Bear 45/70....say for example if i were to put it in first gear. And not in 4low first gear just regular first gear. My trucks gear ratio is 2.45:1. Are you telling me that in first gear if I put my foot down that I'm slapping the blacktop with roughly 2000'# of torque?
 
  #10  
Old 10-24-2011, 10:56 PM
85e150's Avatar
85e150
85e150 is online now
Super Moderator
Join Date: Apr 2004
Posts: 31,869
Received 1,591 Likes on 1,296 Posts
Think about it. If you lean 250 or even 500 lbs into the back of the vehicle, how fast will it accelerate? The gear reduction multiplies the engine torque to get you moving. Note that's the short version of how it works.

Gears just give the twisting force a longer "lever" against the load.
 
  #11  
Old 10-25-2011, 10:52 PM
Bear 45/70's Avatar
Bear 45/70
Bear 45/70 is offline
Post Fiend
Join Date: Mar 2004
Location: Union, Washington
Posts: 6,056
Likes: 0
Received 6 Likes on 6 Posts
Originally Posted by dnunez3418
Bear 45/70....say for example if i were to put it in first gear. And not in 4low first gear just regular first gear. My trucks gear ratio is 2.45:1. Are you telling me that in first gear if I put my foot down that I'm slapping the blacktop with roughly 2000'# of torque?
Those numbers are at PEAK torque which is at 2800 RPM.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Dustball8504
6.0L Power Stroke Diesel
18
11-05-2007 02:08 PM
jhromy
Explorer, Sport Trac, Mountaineer & Aviator
3
01-09-2004 09:17 AM
maximumhorsepower
FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)
10
04-14-2003 04:32 PM
1980F100
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
5
10-24-2002 09:52 AM



Quick Reply: torque



All times are GMT -5. The time now is 02:13 PM.