How much power to pull wheels off ground?
09-21-2004, 12:21 PM
#13
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Join Date: Mar 2004
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RE: How much power to pull wheels off ground?
the bottom line is it takes a fair amount of torque multiplication via first gear in the tranny and the rear end gear along with the necessary amount of torque from the engine plus a good suspension including subframe connectors to make the chassis lift rather than twist.
09-21-2004, 01:45 PM
#15
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RE: How much power to pull wheels off ground?
ORIGINAL: Dbeck002
first you must locate the center of gravity of the car. lets say that in a mustang its exactly in the middle. the car then weighs, 3300 lbs. if the length of a mustang is 9 feet and the center of mass is 3 feet from the rear wheel axle, considering you have 100% traction. the torque you will need to do this is 9900ft-lbs at the axle. factor in say 3.73 gears you will then be looking at 2654 ft-lbs coming out of your tranny. say first gear is 3.6:1 ration the torque output your engine must produce to lift the wheels completely off the ground will be about 750 ft-lbs. of course it could be less because the center of mass and dimensions of the mustang that i gave you are just guesstimates. Hope you have an understanding of how it works though.
first you must locate the center of gravity of the car. lets say that in a mustang its exactly in the middle. the car then weighs, 3300 lbs. if the length of a mustang is 9 feet and the center of mass is 3 feet from the rear wheel axle, considering you have 100% traction. the torque you will need to do this is 9900ft-lbs at the axle. factor in say 3.73 gears you will then be looking at 2654 ft-lbs coming out of your tranny. say first gear is 3.6:1 ration the torque output your engine must produce to lift the wheels completely off the ground will be about 750 ft-lbs. of course it could be less because the center of mass and dimensions of the mustang that i gave you are just guesstimates. Hope you have an understanding of how it works though.
Hope you have an understanding of how it works though.
09-22-2004, 02:45 AM
#16
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RE: How much power to pull wheels off ground?
quote:
ORIGINAL: Dbeck002
first you must locate the center of gravity of the car. lets say that in a mustang its exactly in the middle. the car then weighs, 3300 lbs. if the length of a mustang is 9 feet and the center of mass is 3 feet from the rear wheel axle, considering you have 100% traction. the torque you will need to do this is 9900ft-lbs at the axle. factor in say 3.73 gears you will then be looking at 2654 ft-lbs coming out of your tranny. say first gear is 3.6:1 ration the torque output your engine must produce to lift the wheels completely off the ground will be about 750 ft-lbs. of course it could be less because the center of mass and dimensions of the mustang that i gave you are just guesstimates. Hope you have an understanding of how it works though.
Most cars are between 12 - 14 feet and the center of mass is more like 3 feet from the front wheels - not the rear, and besides your theory would be true only if there was no suspension and 100% traction, but thats not the case. The suspension rising on the front and squatting on the rear will help to "spring" the front tires up off the ground. So in reality its more like 3500 lbs of torque to the wheels with a good suspension - which is more like stock what a mild bolt-on 5.0 would put to the tires with 3.73 gears.
Hope you have an understanding of how it works though.
ORIGINAL: Dbeck002
first you must locate the center of gravity of the car. lets say that in a mustang its exactly in the middle. the car then weighs, 3300 lbs. if the length of a mustang is 9 feet and the center of mass is 3 feet from the rear wheel axle, considering you have 100% traction. the torque you will need to do this is 9900ft-lbs at the axle. factor in say 3.73 gears you will then be looking at 2654 ft-lbs coming out of your tranny. say first gear is 3.6:1 ration the torque output your engine must produce to lift the wheels completely off the ground will be about 750 ft-lbs. of course it could be less because the center of mass and dimensions of the mustang that i gave you are just guesstimates. Hope you have an understanding of how it works though.
Most cars are between 12 - 14 feet and the center of mass is more like 3 feet from the front wheels - not the rear, and besides your theory would be true only if there was no suspension and 100% traction, but thats not the case. The suspension rising on the front and squatting on the rear will help to "spring" the front tires up off the ground. So in reality its more like 3500 lbs of torque to the wheels with a good suspension - which is more like stock what a mild bolt-on 5.0 would put to the tires with 3.73 gears.
Hope you have an understanding of how it works though.
there are different factors that contribute to lifting the wheels off the ground, correct, as i said in the first post i did really rough guesstimates. if you want i can factor in other things like the force exerted on the ground when the car springs up. the instanteous momentum gained as the car starts to move also helping the front end whip backwards, etc... in any case suspension and rigidity of body, the forward acceleration that helps push the front end backward are variables when it comes to lifting the wheels. it may not be exactly 750 ft-lbs but it will be a high number if the car did not have the correct suspension and gearing.
EDIT: Also, the wheel radius plays a big role in this too... there are hundreds of variables to determine how to pull the wheels off the ground, for now lets just stick with lots of TORQUE!!
09-29-2004, 01:01 PM
#19
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RE: How much power to pull wheels off ground?
ORIGINAL: nd_dsm
dbeck your an f-in tool, i dont post much just read around, and i just have to laugh when ever you post.
dbeck your an f-in tool, i dont post much just read around, and i just have to laugh when ever you post.
