nitrous increasing boost?

[red2005ss]

I am running a 35 shot and i am seeing an increase in boost from 12 to 15 when i spray, Is this normal?

[Area47]

yulp.

[red2005ss]

I didnt think it was possible because of the size of the pulley?

[rlinbatonrouge]

I didnt think it was possible because of the size of the pulley?

Boost is a measure of air. Hot air rises because it is less dense than cold air. It is less dense because it has less oxygen. N20 cools the intake charge and adds extra oxygen among other things into the intake. Hence, more boost regardless of the pulley size.

[TheWastedYears]

Which is how nitrous makes its power to begin w/. More oxygen molecues = bigger bang.

[LotusMan]

Hot air rises because it is less dense than cold air. It is less dense because it has less oxygen.

I don't believe that is correct. A change in the temperature of the air does not change how much oxygen is in it. Hot is less dense than cold air because air expands when is gets hotter -- that is, the same number of molecules (or mass) takes up more volume. Heating air means that the molecules are given more energy so they move around a lot more, taking up more space.

Experiment' take a balloon and blow it up. Put it in the fridge. Take it out after it gets cold. You will find it shrunk. As the balloon get back up to room temperature, it will expand and get bigger.

Nitous works in 2 was to produce more power. 1) as notes, it add oxygen to the intake mixture (increasing the oxygen concentration of the air flow), and 2) cools the air flow (expecially in turbo/supercharger application where the compression of the air flow raises it's temperature (physics, ideal gas law: PV=nRT)

[rlinbatonrouge]

Hot air is less dense because the molecules are moving faster and expand more than cold air.

[Cat Ion]

Hot air is less dense because the molecules are moving faster and expand more than cold air.

Zackly! There are some words being bounced around here that don't interrelate. The air is cold because the nitrous is being released from a compressed source. Spray your bathroom spray for a few seconds and feel the bottle. It gets cold. That is a byproduct of decompression.

Before the nitrous is injected, you have a given amount of air being metered into your motor. The airflow is calculated, thus providing a fuel mixture. So you have fuel atomization and air particles. Add nitrous and you now have a higher volume of "air" mixed into the equation. In the fire triangle you have an oxidizer, combustible material and an ignition source. If you remove any one of them you remove the ability to create fire. If you add more of any one of them, you alter the ability to make fire the opposite way. More ignition source (spark duration) makes longer fire, more combustible material (gas) makes longer fire, adding more oxygen particles makes hotter fire. Thus more bang inside the cylinder.

The ability of the nitrous to cool the charge air temp is merely a byproduct that will result in delaying the inevitable heat soak issues we have. Try not to confuse the two.