Intake questions-, how far, and sensor questions Options

[mgnt232]

▼New Questions▼
I have a CAI for my ST, I feel like it gave me a little more power over stock, but it used to hang down on the tranni, and the heat shield use to actually get a little hot, and I assume the air isn't all that cold.
So I moved the piping around and got a little more to bend further. I got it almost to the driver side turn signal. With the invader kit, its a big opening under the turn, and thats right about where it rests.
I dont feel much of a difference from when it was in it original place and now, although it sounds better . I was wondering, do you loose power if you go too far with the CAI piping?
thanks-
Also My air intake sensor (temp sensor?) is wrapped like 75% in electrical tape, never noticed it before. But should I take it off? would this affect anything?




▼Cleaning Air filter question ▼
I know there are K&N cleaner kits.... but I dont think its worth the money to buy since its not really dirty.
I have a pressure washer, so I was wondering can I just lightly wash it, would that get the dirt and particles out?
thanks!

This post has been edited by mgnt232: Jun 16, 2010 - 11:39 AM

[hatchy_gt-s]

The reason your rpms increased is simple science colder air is more dense allowing for more intake. Thats also a good way to intake water which has a bad outcome. DO NOT USE DRY ICE!!! Dry ice is solid carbon dioxide (what you exhale), not only is it less dense, but it will make your CEL come on, and damage you car.

You really need to go back to 6th grade science dude

Edit: If you lengthen the pipe you want to decrease the size. If your car intakes 250cfm and your original pipe is 250cfm and you increase the length without decreasing the diameter you will have say a 350cfm pipe causing drag because your intake is at a -100cfm.
cfm= cubic feet per minute
^Thats basic fluid dynamics (thats like 7th grade science)
In conclusion decrease your pipe to a 1 1/2 or 2in pipe, and DO NOT USE DRY ICE!!!

This post has been edited by hatchy_gt-s: Jun 16, 2010 - 10:40 PM

[solidxsnake]

The reason your rpms increased is simple science colder air is more dense allowing for more intake. Thats also a good way to intake water which has a bad outcome. DO NOT USE DRY ICE!!! Dry ice is solid carbon dioxide (what you exhale), not only is it less dense, but it will make your CEL come on, and damage you car.

You really need to go back to 6th grade science dude

Edit: If you lengthen the pipe you want to decrease the size. If your car intakes 250cfm and your original pipe is 250cfm and you increase the length without decreasing the diameter you will have say a 350cfm pipe causing drag because your intake is at a -100cfm.
cfm= cubic feet per minute

In conclusion decrease your pipe to a 1 1/2 or 2in pipe, and DO NOT USE DRY ICE!!!

How does increasing the length change the flow-rate? The only place air is coming into the intake is through the filter, which isn't changing.

[hatchy_gt-s]

The reason your rpms increased is simple science colder air is more dense allowing for more intake. Thats also a good way to intake water which has a bad outcome. DO NOT USE DRY ICE!!! Dry ice is solid carbon dioxide (what you exhale), not only is it less dense, but it will make your CEL come on, and damage you car.

You really need to go back to 6th grade science dude

Edit: If you lengthen the pipe you want to decrease the size. If your car intakes 250cfm and your original pipe is 250cfm and you increase the length without decreasing the diameter you will have say a 350cfm pipe causing drag because your intake is at a -100cfm.
cfm= cubic feet per minute

In conclusion decrease your pipe to a 1 1/2 or 2in pipe, and DO NOT USE DRY ICE!!!

How does increasing the length change the flow-rate? The only place air is coming into the intake is through the filter, which isn't changing.

Think more area not flow rate. A pipe can only intake so much the 350cfm rating was for the pipe not the car.

Think of a straw if you increase the diameter w/o decreasing the length you have less pressure same as if you increase the length w/o decreasing the diameter.

This post has been edited by hatchy_gt-s: Jun 16, 2010 - 10:48 PM

[azian_advanced]

its not the length, its the number and the angle of bends

actually, the length of a pipe has an influence on power (longer pipe = more pressure loss), although very small compared to angles and bends.

Edit: If you lengthen the pipe you want to decrease the size. If your car intakes 250cfm and your original pipe is 250cfm and you increase the length without decreasing the diameter you will have say a 350cfm pipe causing drag because your intake is at a -100cfm.
cfm= cubic feet per minute

so what you're recommending is to match the volume of the original pipe with the volume of the piping in the CAI setup?
the only reason one would reduce the pipe diameter is to increase flow velocity which helps reduce heat soak from the engine, but at the cost of pressure loss.

[hatchy_gt-s]

Edit: If you lengthen the pipe you want to decrease the size. If your car intakes 250cfm and your original pipe is 250cfm and you increase the length without decreasing the diameter you will have say a 350cfm pipe causing drag because your intake is at a -100cfm.
cfm= cubic feet per minute

so what you're recommending is to match the volume of the original pipe with the volume of the piping in the CAI setup?
the only reason one would reduce the pipe diameter is to increase flow velocity which helps reduce heat soak from the engine, but at the cost of pressure loss.

You dont loose pressure if you lengthen and decrease diameter. If I have something that is 14in long and 3in diameter that gives me 99 cubic inches , and if I extend it to 18in with a diameter of 1 3/4in it gives me 99 cubic inches of volume. So if I have the same volume I have the same amount of pressure.
The equation for Volume is;
Pi x radius squared x hight
or Pi*r2*h
or 3.14*r2*h
The equation for pressure is;
normal force(14.7)/area=pressure
or F/A=P
or for cars 14.7/A=P
The only thing you change when you change length is distance ie the time it takes to reach the car.(I dont think you really want me to get into the math of that to)

This post has been edited by hatchy_gt-s: Jun 17, 2010 - 11:59 PM

[solidxsnake]

Edit: If you lengthen the pipe you want to decrease the size. If your car intakes 250cfm and your original pipe is 250cfm and you increase the length without decreasing the diameter you will have say a 350cfm pipe causing drag because your intake is at a -100cfm.
cfm= cubic feet per minute

so what you're recommending is to match the volume of the original pipe with the volume of the piping in the CAI setup?
the only reason one would reduce the pipe diameter is to increase flow velocity which helps reduce heat soak from the engine, but at the cost of pressure loss.

You dont loose pressure if you lengthen and decrease diameter. If I have something that is 14in long and 3in diameter that gives me 99 cubic inches , and if I extend it to 18in with a diameter of 1 3/4in it gives me 99 cubic inches of volume. So if I have the same volume I have the same amount of pressure.
The equation for Volume is;
Pi x radius squared x hight
or Pi*r2*h
or 3.14*r2*h
The equation for pressure is;
normal force(14.7)/area=pressure
or F/A=P
or for cars 14.7/A=P
The only thing you change when you change length is distance ie the time it takes to reach the car.(I dont think you really want me to get into the math of that to)

So again, how does changing the length of the pipe change flow rate or pressure? As you just said, the only thing that changes with length is the time it takes for air entering the filter to reach the throttle body (essentially). Changing the volume of the pipe won't change anything as long as the volume change is due to length and not diameter. As air is used by the engine, the air at the intake end of the pipe will displace the air that was just used due to the fact that a gas will expand to fill its container. Thus, as long as there is always air in the intake pipe (which there is, there's no vacuum there), there will always be the same pressure for any given length of pipe of the same diameter. Volume is entirely unrelated to pressure in this case.

In a closed container, volume and pressure are inversely related, absolutely. However, an intake pipe is not a closed container, one end is open to the atmosphere, the other feeds into the throttle body of the engine. Since this is in the case of a N/A engine, the pressure inside the pipe will always be 1kPa (roughly) no matter what the pipe's volume. The flow rate is entirely related to the diameter of the pipe (for a given pipe with the same gas moving through it, A₁V₁ = A₂V₂), thus changing the diameter of the pipe will surely change the flow rate (the narrowest part of the pipe will dictate the flow rate due to the bottleneck it causes). Also, the flow rate is related to the opening of the pipe. In this case, the opening would be the air filter, which surely causes a bottleneck over having a wide-open end. Changing the length will negligibly affect the flow rate, as once the air is used by the engine, it leaves an empty space which is then filled by more air in the pipe, pushed in by the force of the atmosphere. To prove it, you could take a pump with the inlet connected to a reservoir of a given volume of fluid. You'd get different lengths of the same diameter tubing and time the time it takes for the pump to empty the first reservoir, and what you'll notice is that the time it takes will not change no matter how long the tubing is. The given volume of the fluid divided by the time is the flow rate of the pump (in the units you used before: (cu. ft.)/(min)).

I'm not trying to deny what you're saying, but I just can't wrap my head around it and am debating for the sake of my own curiosity

edit: Where does the 14.7 come from when you use 14.7/A = P? You didn't give units, but I assume you mean 14.7psi. That's entirely a false equation, because psi (lbs./sq. in.) is a unit of pressure, not force. Thus, you'd plug it into F/A=P for P, and not F.

This post has been edited by solidxsnake: Jun 25, 2010 - 10:39 AM