Jerryl
Tall Unvaccinated Chinese Guy
- Joined
- Dec 14, 2004
Some of you may think this is a waste of time , . . . . but if you read the whole thing you would at least appreciate my perspective . . . .
This all started with this thread . . . . . that got me thinking . . . http://turbobuick.com/forums/threads/wot-correction-off-with-alky.370524/
There is some good discussion/info in this thread with a few variables that have not been identified/confirmed/explained in my mind.
First off here are some definitions direct from Wikipedia;
- Flash point - The flash point of a volatile material is the lowest temperature at which it can vaporize to form an ignitable mixture in air.
- Boiling point - The boiling point of a substance is the temperature at which the vapor pressure of the liquid equals the environmental pressure surrounding the liquid.
- Vapor pressure - Vapor pressure or equilibrium vapor pressure is the pressure of a vapor in thermodynamic equilibrium with its condensed phases in a closed system.
- Vapor - A vapor is a substance in the gas phase at a temperature lower than its critical point.[1] This means that the vapor can be condensed to a liquid or to a solid by increasing its pressure without reducing the temperature.
So . . . based on the definitions and some simple physics, I set out for some review and came up with some “General” Facts:
· Cooler temps at constant pressure have an effect on the required time for vaporization of any liquid.
· Boost pressures raise the boiling temperature of ANY liquids.
· Too much alky with insufficient “heat” under XX pressure will results in a wet flow condition.
· The intake design is not conducive to “wet flow”.
· Air has a LOT more mass than we sometimes think about.
With these, I decided to do some quick calculations (Just for my own appreciation);
Say you have a (XXX) HP car . . . . . . what is the calculated air velocity through the stock IC TB in (XX) mph?
Why would I care you ask? Ever seen it rain in a hurricane or drive through the rain at 70 MPH? Now, think what happens with “wet flow - mass” at that velocity.
Again . . . the velocity through the stock TB for the listed HP is calculated at:
300 HP – 47 MPH
400 HP – 62 MPH
500 HP – 78 MPH
600 HP – 93 MPH
Now . . . on a 600HP set-up, you need about 60lb/min of air, and if we add mass (alcohol) to it. . . . . . we are feeding the motor +6 lbs a second (Air and meth) whish travel at +90 mph.
Let’s put this in perspective;
A baseball weights 5 1/8 ounce (0.427 lb) . . . We are feeding 14 times the weight of a baseball/sec, at +90 MPH! . . . . Think of the force required to change the direction of the inertia!
Oh . . . . 600 HP car . . . . through a 2” tube (Up pipe), the air velocity is 117 MPH.
The kinetic energy of the mass/sec = ½ MV^2 = ½ x 6lbs/sec x 90MPH^2 = ½ x 2.72 kg x 41.5^2 m/sec = 2.34 KJ = 1733 lb.ft of torsional force!
I had to do it twice to make sure I had the number correct . . . . .
Although this cacluation is inconclusive to the experienced condition(s) in the listed thread, it is interesting if you think of air and fuel traveling at mph and trying to make the turn . . . . .
Anyway . . . although Grumpy, Razor, Bison, Turbofabricator, Paul, etc . . . have already proven this to be a mute point , it is the start of “my” hypothesis . . . . .
.
This all started with this thread . . . . . that got me thinking . . . http://turbobuick.com/forums/threads/wot-correction-off-with-alky.370524/
There is some good discussion/info in this thread with a few variables that have not been identified/confirmed/explained in my mind.
First off here are some definitions direct from Wikipedia;
- Flash point - The flash point of a volatile material is the lowest temperature at which it can vaporize to form an ignitable mixture in air.
- Boiling point - The boiling point of a substance is the temperature at which the vapor pressure of the liquid equals the environmental pressure surrounding the liquid.
- Vapor pressure - Vapor pressure or equilibrium vapor pressure is the pressure of a vapor in thermodynamic equilibrium with its condensed phases in a closed system.
- Vapor - A vapor is a substance in the gas phase at a temperature lower than its critical point.[1] This means that the vapor can be condensed to a liquid or to a solid by increasing its pressure without reducing the temperature.
So . . . based on the definitions and some simple physics, I set out for some review and came up with some “General” Facts:
· Cooler temps at constant pressure have an effect on the required time for vaporization of any liquid.
· Boost pressures raise the boiling temperature of ANY liquids.
· Too much alky with insufficient “heat” under XX pressure will results in a wet flow condition.
· The intake design is not conducive to “wet flow”.
· Air has a LOT more mass than we sometimes think about.
With these, I decided to do some quick calculations (Just for my own appreciation);
Say you have a (XXX) HP car . . . . . . what is the calculated air velocity through the stock IC TB in (XX) mph?
Why would I care you ask? Ever seen it rain in a hurricane or drive through the rain at 70 MPH? Now, think what happens with “wet flow - mass” at that velocity.
Again . . . the velocity through the stock TB for the listed HP is calculated at:
300 HP – 47 MPH
400 HP – 62 MPH
500 HP – 78 MPH
600 HP – 93 MPH
Now . . . on a 600HP set-up, you need about 60lb/min of air, and if we add mass (alcohol) to it. . . . . . we are feeding the motor +6 lbs a second (Air and meth) whish travel at +90 mph.
Let’s put this in perspective;
A baseball weights 5 1/8 ounce (0.427 lb) . . . We are feeding 14 times the weight of a baseball/sec, at +90 MPH! . . . . Think of the force required to change the direction of the inertia!
Oh . . . . 600 HP car . . . . through a 2” tube (Up pipe), the air velocity is 117 MPH.
The kinetic energy of the mass/sec = ½ MV^2 = ½ x 6lbs/sec x 90MPH^2 = ½ x 2.72 kg x 41.5^2 m/sec = 2.34 KJ = 1733 lb.ft of torsional force!
I had to do it twice to make sure I had the number correct . . . . .
Although this cacluation is inconclusive to the experienced condition(s) in the listed thread, it is interesting if you think of air and fuel traveling at mph and trying to make the turn . . . . .
Anyway . . . although Grumpy, Razor, Bison, Turbofabricator, Paul, etc . . . have already proven this to be a mute point , it is the start of “my” hypothesis . . . . .
.