Thermal conductivity: metal v. plastic?

Modifying plastics to improve their thermal conductivity is a burgeoning area of opportunity for a handful of compounders. They have taken up the challenge of using plastics to solve problems of heat build-up in electronics, appliances, lighting, automotive, and industrial products.

Air Temperature

The biggest advantage a cold-air intake has over a short-ram intake is that it allows the motor to pull in colder air from a location away from the heat of the engine. The temperature of the air under the hood rises due to residual heat from the radiator and cooling system. A cold air intake avoids this by using air from another location, such as the spaces around the wheel wells or inside the front bumper. This increases the power potential of the intake charge. The reason is simple: cold air is denser than heated air.

Since we already know more fuel mixed with more air equals more power by using cooler, denser air, a cold air intake is able to add more fuel per-unit-volume of air. This is especially important when the car is moving slowly or starting from a stop. When the car isn’t moving, hot air gathers underneath the hood. A short ram intake is forced to use this heated air for the intake charge, which means it loses power. The cold air style intake isn’t affected as much under these conditions. However once the car is moving, the difference in performance between the two is much less noticeable since the temperature under the hood drops considerably.

What Does an Air Intake Resonator Do?

Design and Construction

The resonator itself couldn't be simpler in design; it's basically just an expansion chamber or wide spot in the otherwise-smooth intake pipe. It may or may not contain some kind of baffle or plate, depending upon the design and the intent of the designers. Resonators come in two types: In-line resonators are open chambers that sit in the intake tube, while side-branch resonators are chambers that sit next to the tube and are connected to it via a small duct or channel.

Pressure Wave Harmonics

Air flowing into your cylinder head's intake port doesn't move in a straight line while the valve is open, then politely stop in its tracks to await another valve opening. When the valve closes, the moving column of air slams into it, then compresses and bounces back like a spring. This pressure wave travels backward at the speed of sound until the intake runner opens up or it hits something, and then it bounces back toward the cylinder. This is the "first harmonic." The pressure wave actually bounces back and forth two or three more times before the intake valve opens again.

Intake Tube Pulses

The resonator in your intake is technically known as a Helmholz resonator, an acoustic device used to control pressure wave harmonics. Air bouncing back out of your engine and into the intake tube doesn't do it in a single pulse the way it would in a single intake runner; the multiple pistons put out pressure waves at their own intervals, and some of those are going to try to bounce back in while others are going out. The result is a "clog" or high pressure area in your intake tube that ultimately limits airflow through almost the entire rpm spectrum.

The Resonator

Adding an expansion chamber to the intake tube forces air coming back out of the engine to slow down to fill the cavity, thus expending a great deal of its energy and slowing the pressure wave reversion. This slowdown allows fresh air to flow toward the engine without fighting pressure reversion waves the entire way, thus aiding in cylinder filling. Since these pressure waves are essentially sound, giving them a place to expend their energy before exiting the air filter box ends up dampening the intake noise and quieting the engine. Thus, the resonator helps to make the engine paradoxically quieter and more powerful.

 

Thank you for all the written material.

 

 

 

Do you have a patent for that listening tool? I use a Mechanic's Stethoscope
My 3 developed that noise and it was coming the idler pulley I replaced belt, tensioner, and idler at the same time. Saved old spare parts as emergency backup.

 

In the tank is not cleaning the intake. Yes, I use liquid tape to seal wire to terminal connections, works great!
Grab a beer and watch these:

 

Got it haha. I'll pick some of the SeaFoam spray on my way home from work tomorrow morning. I have to get some power steering fluid to do a flush, as well.

The old PCM was never updated with the 3.7L swap. I am probably going to buy the HPtuners tool soon so I can segment swap for the engine, adjust speedometer, and play with the shift points. I want to make sure some of the weird little problems aren't related to the PCM thinking it is still running a 3.5L. I wish HPtuners had a diagnostic setup similar to the Autel tool, which I would love to have, too. Maybe one day. I figure having the tuning tool will be helpful for learning more and being able to tweak along the way. I did consider a mail order but think the tool is more consistent with my style.

 

 

Anyone have a spare power steering reservoir?

 

What did you do? Reservoir 25948637been discontinued for years, 25932019 pump comes with reservoir. Head over to ebay and ask the sellers if they include the reservoir? hummer h3 power steering pump
Recently sold prices: hummer h3 power steering pump