So what increases Torque
#11
12-17-2005, 03:07 AM
Pro Rider
Join Date: Mar 2005
Location: illinois
Posts: 583
Likes: 0
Received 0 Likes
on
0 Posts
#12
12-17-2005, 07:05 AM
So what increases Torque
Originally posted by: midnite
Oldmanm racing, I have 2 questions. Can a naturally asperated motor achieve %100 volumetric effiency? Can a turbo, or blown motor achieve more than %100 volumetric effiency? Thanks.
Oldmanm racing, I have 2 questions. Can a naturally asperated motor achieve %100 volumetric effiency? Can a turbo, or blown motor achieve more than %100 volumetric effiency? Thanks.
#13
12-17-2005, 07:06 AM
So what increases Torque
Originally posted by: Oldmanracing
Once your motor reaches 100% V.E. the torque per engine size is maxed out.
650=55lbs 730=61lbs 800=67lbs
The cam just moves the torque to the rpm range you are want to ride in.
If you overcam, you will sacrifice torque for more hp.
Once your motor reaches 100% V.E. the torque per engine size is maxed out.
650=55lbs 730=61lbs 800=67lbs
The cam just moves the torque to the rpm range you are want to ride in.
If you overcam, you will sacrifice torque for more hp.
#14
12-17-2005, 07:10 AM
Extreme Pro Rider
Join Date: Apr 2004
Posts: 4,078
Likes: 0
Received 0 Likes
on
0 Posts
#15
12-17-2005, 09:25 AM
So what increases Torque
Originally posted by: ERBEDS650
Torque is what gets up the sand hills right??? not just Horse Power? SO what make MORE torque on the DS?
Torque is what gets up the sand hills right??? not just Horse Power? SO what make MORE torque on the DS?
Torque does not have to cost $. After all, Look at the end cap and Nitrous. Both increase torque in huge ways, but dont cost that much.
#16
12-17-2005, 09:32 AM
#18
12-18-2005, 01:57 AM
So what increases Torque
How's it calculated?
The Society of Automotive Engineers (SAE) has created a standard method for correcting horsepower and torque readings so that they will seem as if the readings had all been taken at the same "standard" test cell where the air pressure, humidity and air temperature are held constant.
The equation for the dyno correction factor given in SAE J1349 JUN90, converted to pressure in mb, is:
where:
cf = the dyno correction factor
Pd = the pressure of the dry air, mb
Tc = ambient temperature, deg C
The pressure of the dry air Pd, is found by subtracting the vapor pressure Pv from the actual air pressure. The relative horsepower is simply the mathematical reciprocal of the correction factor.
Horsepower and Torque:
Power is the rate at which work is done. When the engine torque is turning the crankshaft and power is being delivered, the resulting horsepower may be expressed as:
Which can be simplified as:
where:
hp = horsepower, hp
t = torque, ft-lbs
rpm = engine speed, revolutions per minute
This is a great formula. Basically it says that if you can keep the same amount of torque, then the more rpm you can turn, the more horsepower you get!
That's why Formula One and CART and IRL engines all turn incredible rpm. The faster the engine turns, the more power it can make (when it's properly tuned to operate at that speed).
Consider for example: a normally aspirated internal combustion engine typically produces about 1 to 1.5 ft-lbs of torque per cubic inch when it is properly tuned to operate at any specific rpm. With a 2 litre (1 litre is about 61 cubic inches) engine, producing 1.5 ft-lbs of torque per cubic inch, you would expect to get about 180 hp at 5200 rpm... but you will get a whopping 415 hp if you can get it to run at 12,000 rpm.
The 3.5 liter IRL engine is reported to produce about 650 hp at 10,700 rpm. That would be about 1.5 ft-lbs per cubic inch.
The Ferrari 3.0 liter Formula One engine is rumored to produce about 860 hp at 18,500 rpm. That would be about 1.33 ft-lbs per cubic inch.
And at the other end of the rpm spectrum, one model of the 360 cubic inch four cylinder Lycoming IO-360 aircraft engine produces 180 hp at 2700 rpm, which is 0.97 ft-lbs per cubic inch.
In general, production automobile engines that have a broad torque band will produce about 0.9 to 1.1 ft-lbs per cubic inch. Highly tuned production engines, such as the Honda S2000 or the Ferrari F50 are in the range of 1.1 to 1.3 ft-lbs per cubic inch. Highly tuned race engines such as NASCAR, IRL and Formula One are often in the range of 1.3 to 1.5 ft-lbs per cubic inch.
For the DS I thought that with carbs, that a 1.375 ft-lbs per cubic inch was about right.
The Society of Automotive Engineers (SAE) has created a standard method for correcting horsepower and torque readings so that they will seem as if the readings had all been taken at the same "standard" test cell where the air pressure, humidity and air temperature are held constant.
The equation for the dyno correction factor given in SAE J1349 JUN90, converted to pressure in mb, is:
where:
cf = the dyno correction factor
Pd = the pressure of the dry air, mb
Tc = ambient temperature, deg C
The pressure of the dry air Pd, is found by subtracting the vapor pressure Pv from the actual air pressure. The relative horsepower is simply the mathematical reciprocal of the correction factor.
Horsepower and Torque:
Power is the rate at which work is done. When the engine torque is turning the crankshaft and power is being delivered, the resulting horsepower may be expressed as:
Which can be simplified as:
where:
hp = horsepower, hp
t = torque, ft-lbs
rpm = engine speed, revolutions per minute
This is a great formula. Basically it says that if you can keep the same amount of torque, then the more rpm you can turn, the more horsepower you get!
That's why Formula One and CART and IRL engines all turn incredible rpm. The faster the engine turns, the more power it can make (when it's properly tuned to operate at that speed).
Consider for example: a normally aspirated internal combustion engine typically produces about 1 to 1.5 ft-lbs of torque per cubic inch when it is properly tuned to operate at any specific rpm. With a 2 litre (1 litre is about 61 cubic inches) engine, producing 1.5 ft-lbs of torque per cubic inch, you would expect to get about 180 hp at 5200 rpm... but you will get a whopping 415 hp if you can get it to run at 12,000 rpm.
The 3.5 liter IRL engine is reported to produce about 650 hp at 10,700 rpm. That would be about 1.5 ft-lbs per cubic inch.
The Ferrari 3.0 liter Formula One engine is rumored to produce about 860 hp at 18,500 rpm. That would be about 1.33 ft-lbs per cubic inch.
And at the other end of the rpm spectrum, one model of the 360 cubic inch four cylinder Lycoming IO-360 aircraft engine produces 180 hp at 2700 rpm, which is 0.97 ft-lbs per cubic inch.
In general, production automobile engines that have a broad torque band will produce about 0.9 to 1.1 ft-lbs per cubic inch. Highly tuned production engines, such as the Honda S2000 or the Ferrari F50 are in the range of 1.1 to 1.3 ft-lbs per cubic inch. Highly tuned race engines such as NASCAR, IRL and Formula One are often in the range of 1.3 to 1.5 ft-lbs per cubic inch.
For the DS I thought that with carbs, that a 1.375 ft-lbs per cubic inch was about right.
#19
12-18-2005, 02:03 AM
