Home brew intake mods

[Christ]

We've already tried.

Unless you can come up with some data and testing to prove what you're saying, this discussion isn't going to go anywhere.

If you're cruising at 65 MPH, and it takes 14HP to keep you cruising steady-state, and you then add colder air, the ECM compensates by adding more fuel, causing you to create more power. You will begin to accelerate. You then reduce your throttle angle, which increases your engine's pumping losses, reducing it's efficiency. We're talking in simple terms, here, so we'll not even address the adiabatic benefit of warmer intake air.

What you've done by adding colder air is not increase the engine's efficiency, you've told the engine to increase the fuel volume. Making more HP at the same RPM is not a function of engine efficiency unless the fuel volume remains constant. Efficiency is a measure of HP per unit of fuel.

When you let off the throttle to compensate for additional power, you've lessened the engine's ability to breathe clearly, thus reducing the intake air charge and the amount of fuel injected, and to that extent, the HP that the engine can create per % of throttle angle. Doing so means that for each stroke, the engine is capable of drawing less air than at a larger throttle angle with the same air density, and since VE is directly linked to overall efficiency, decreasing VE means that the engine is working harder. VE is measured by determining the actual input compared to the size of the engine's "neutral size" or maximum volume at rest.

It takes a certain amount of power just to keep an engine spinning, and part of that power is overcoming vacuum, which is created by the throttle plate. The less vacuum, the less power is consumed by induction losses. To make less vacuum, you open the throttle plate more, or reduce the density of the air mass being induced. You're trying to do exactly the opposite.

[Jyden]

Well - what I have done by lowering the air temp is raising the amount of oxygine awaileble to the engine.

When you have more oxygen in the mix, you generate more Kw with the same amount of Fuel.....

If what you say is true - your engine would work just as good in high altitudes in thin air - is dosen't. It's depraved / starved of oxygen. This is well known

When you add NOX you increase engine work / power-output / Kw at a given RPM.

When the tractor pulling guys inject waterdrops they increase oxygen levels.

When you turbocharge an engine you put more air thus also oxygen in.

Oxygen is the critical factor in the petrol / gas mix to produce power. Its the "short" factor. The more oxygen you can get in the better for the cumbostion and Kw output. (up till a certain point)

As cold air contain more oxygen than warm air, your engine will produce more power at a given RPM on cold air than it will on warm air.

Thats why you put intercoolers on engines. It's to lower the intake air temp and raise oxygen levels.

Ever tried ridig your bike through a mist or fog on a summer evenig? Yes you can let go a bit on the throttle, as the moisture in the air supplies the engine with more oxygen rich air.

Now - that said - the past 10 year development in engine management progamming has taken a turn wich prioritises emmisions.

So on some engine management systems (EMS) the ECU will "overide" the powergains from the extra oxygen, as to maintain a certain working temp in the catalytic converter, and a certain combustion temperature.

This will to some extent work in the opposite direction of the advantaged of the extra oxygen in the cold air.

But I agree with you - we will never agree on this. We saw plenty of evidence when I worked with this 10 years ago. Sadly I don't have assecs to the data anymore.

So it's down to what practical tests folks can come up with.

But I belive, that it also comes down to how the EMS is set up. If the engine and EMS prioritses lean burn and thus hot air, a HAI will benefit the engine.

So - let agree on, that we disagree

[White118]

OK, so in a nut shell. Because the engine is small it will run more efficient on warmer air because the engine uses a lot of energy turning the cold oil over. On the other hand when it is warmed up it would run better on cold air induction because your pulling more air by volume due to it being more dense with oxygen and having to work harder to warm that air up to use it.

It's kind of like you body and cold water you body has to use energy to heat the water before it could use the water. So if you used water that was closer to your body temp it would get processed faster thus hydration you faster.

-Matt

[Christ]

Originally Posted by Jyden

Well - what I have done by lowering the air temp is raising the amount of oxygine awaileble to the engine.

When you have more oxygen in the mix, you generate more Kw with the same amount of Fuel.....

If what you say is true - your engine would work just as good in high altitudes in thin air - is dosen't. It's depraved / starved of oxygen. This is well known

When you add NOX you increase engine work / power-output / Kw at a given RPM.

When the tractor pulling guys inject waterdrops they increase oxygen levels.

When you turbocharge an engine you put more air thus also oxygen in.

Oxygen is the critical factor in the petrol / gas mix to produce power. Its the "short" factor. The more oxygen you can get in the better for the cumbostion and Kw output. (up till a certain point)

As cold air contain more oxygen than warm air, your engine will produce more power at a given RPM on cold air than it will on warm air.

Thats why you put intercoolers on engines. It's to lower the intake air temp and raise oxygen levels.

Ever tried ridig your bike through a mist or fog on a summer evenig? Yes you can let go a bit on the throttle, as the moisture in the air supplies the engine with more oxygen rich air.

Now - that said - the past 10 year development in engine management progamming has taken a turn wich prioritises emmisions.

So on some engine management systems (EMS) the ECU will "overide" the powergains from the extra oxygen, as to maintain a certain working temp in the catalytic converter, and a certain combustion temperature.

This will to some extent work in the opposite direction of the advantaged of the extra oxygen in the cold air.

But I agree with you - we will never agree on this. We saw plenty of evidence when I worked with this 10 years ago. Sadly I don't have assecs to the data anymore.

So it's down to what practical tests folks can come up with.

But I belive, that it also comes down to how the EMS is set up. If the engine and EMS prioritses lean burn and thus hot air, a HAI will benefit the engine.

So - let agree on, that we disagree

While we tend to prefer engineering and proper science here at Ecomodder, you certainly are welcome to substitute your own reality where it fits.

/discussion

[Daox]

Originally Posted by Jyden

So on some engine management systems (EMS) the ECU will "overide" the powergains from the extra oxygen, as to maintain a certain working temp in the catalytic converter, and a certain combustion temperature.

The EMS doesn't override the power gains, it maintains the same air/fuel ratio regardless of how much oxygen you have coming into the engine. This is how all modern fuel injected engines have worked for the past 20 years. Anything with an oxygen sensor will adjust fuel injection based on the amount of oxygen in the exhaust gas. If you add oxygen, no matter where it comes from (cai, turbo, nitrous), its going to inject more fuel.

[Jyden]

Originally Posted by Daox

The EMS doesn't override the power gains, it maintains the same air/fuel ratio regardless of how much oxygen you have coming into the engine. This is how all modern fuel injected engines have worked for the past 20 years. Anything with an oxygen sensor will adjust fuel injection based on the amount of oxygen in the exhaust gas. If you add oxygen, no matter where it comes from (cai, turbo, nitrous), its going to inject more fuel.

I agree 100% with that.

More oxygen = more fuel = more kw

[Jyden]

Originally Posted by Christ

We've already tried.
To make less vacuum, you open the throttle plate more, or reduce the density of the air mass being induced. You're trying to do exactly the opposite.

If you are right about this - your engine should run better - FE wise - in an high altitude environment where the air is thinner, but to my knowledge it dosen't.

I dies - looses power due to oxygen starvation.

So some where your agumentation is flawed - or your sience.... ?

[Daox]

Cars at higher elevations do get better mileage. Its only only due to wider throttle throttle openings, but also having to push the car through less dense air. Of course, you do loose power.

[tjts1]

Large forward facing CAI is the only way to go for FE.

Originally Posted by Daox

Cars at higher elevations do get better mileage. Its only only due to wider throttle throttle openings, but also having to push the car through less dense air. Of course, you do loose power.

This is the biggie. The throttle angle is irrelevant.

[phord]

When talking about CAI/WAI lets not forget air pressure(cold doesnt always mean more air), season(read some aviation performance charts) and weather(here in Pacific NW rain has big negative impact on FE.