which parts in a car produce pressure?

Can you be a little more specific about what you are trying to do? Your question about "Pressure" doesn't make much sense, other than to imagine you're asking about a pump to pump up air pressure in an air suspension system or an oil pump to pump oil through the motor.

Piezoelectric chip? Yeah, they can be used to generate electricity, but just how much electricity are you attempting to produce? At best they produce very small amounts of voltage. There ARE PE chips that generate a high enough voltage to send a spark to ignite a flame (such as on your barbecue or your furnace) but they require a very sharp shock (hit) to do so.

If you're thinking of using a microphone to produce electricity you'll need a very large number of them just to produce a reasonable voltage for charging a battery. But for power (electrical current) they won't produce much in the way of wattage.

Let us know just what it is you're attempting and we might be able to help.

'av'a g'day mate.

'')

OK, thanks for the additional details. Interesting what John said about "FREE ENERGY". There's no such thing. Energy exists in various forms. It can neither be created nor destroyed. It can only be changed from one state to another. Often when changing from one state to another some of the energy is lost as heat or friction.

What you're looking for is "UNTAPPED" energy. But for a piezo to be effective it needs to experience changing energy. Sound waves or vibrations produce changing pressure waves that can be converted into electrical energy.

The cheapest and fastest way to test out what you may gain is to put a piezo onto the PCV tube (Positive Crankcase Ventilation). There you're going to be finding plenty of pressure waves caused by combustion gasses bypassing the rings. You SHOULD be able to get some measure of voltage from there.

John mentioned hydrogen. Here's the thing about that: It takes energy to release the hydrogen. Then you burn the hydrogen to create heat and mechanical energy. That mechanical energy turns the alternator and produces more electrical energy, which can then be used to release more hydrogen from water.

The physics of that is that you get out as much energy as you put in. Not more energy - that's impossible. Anyone who tells you otherwise is lying. And I've seen many of those claims that boast of a 125% increase in fuel mileage. Then they ask you for money for their plans. The only thing being increased is their wealth and your experience being taken for a fool.

Still, your approach isn't to use energy to create energy, it sounds more like you're attempting to find untapped sources of energy that are otherwise wasted.

Air movement is a good source of untapped energy. If you can make it work then you will become a very rich man. But don't go buying that Cadillac just yet.

One theory we tried many years ago was the use of thermocouples for removing heat from a spacecraft and dissipating that energy outside the ship via electric lights. In theory it works because you are converting heat energy into electrical energy then transmitting it outside by converting that electrical energy into light energy.

The system works but is extremely heavy and not very efficient. The use of thermocouples for reclaiming heat (unwanted heat) inside a spacecraft also requires moving air. You might think that warm air rises. But that only works in gravity environments. In space there is no gravity, so you need a fan to move the air. Now you're using more energy than you are creating AND the fan is also generating a source of heat that needs to be dealt with. So from a practical prospective, changing energy should be done as little as possible. The more you convert it the more you waste.

But I applaud your idea for utilizing untapped energy. You're not creating it, you're liberating it. Good for you.

")

The magnetic field of your alternator is a constant force of energy! I use mine to produce a bit of Hydrogen at a molecular level. You can add an A/C converter to produce 110 volts! I have a Quartz stone with three sets of windings but have been unable to produce a answer as they are petrified to the stone! We are still a little behind what the Ancients knew in some fields!

still not real sure what your trying to accomplish but the only places on a motor that " produce " pressure that I can think of that would be remotely useable would be to tap into an oil galley possible with a t connecter off and oil pressure sending unit or such. the exhaust system also produce pressure and is used to run turbo charger's on vehicles so equipped. but can't think of anything that actually makes " air pressure " if that's what your looking for. and I have no idea if either one of them can be converted to what your looking for.