Warm air intake on a Focus....

[user removed]

Pretty sure the Focus is not a return loop fuel system, only one line from the pump to the injectors. The pressure regulator sends a signal to the ECU which sends another signal to the fuel pump module, which varies the voltage to the pump and the resulting fuel pressure variation.

Whew! complicated system, but bottom line is the fuel gets heated by the engine itself, potentially providing better vaporization.

Sentra's test while very thorough was in ambient temps no where near as dramatic as some members here experience, so the WAI may help your mileage to a significant degree if your ambient temps are below freezing, more so if they are significantly below freezing. Some here are dealing with cold so severe that they could probably cool their engine with just the heater core!

I love the idea of a heater core in the air filter intake housing. The only downside of that would be it might make the coolant coming out of the radiator even more cold which could reduce mileage a little but probably not much.

One of the things I think would make a heck of a lot of difference would be to have adjustable venetian blind like louvers in front of the radiator that were thermostatically controlled by the radiator return hose to the engine. This would be an automatic radiator block that maintained a constant return coolant temperature (radiator to engine) at temps similar to summertime.

If you feel the top hose (engine to radiator) then the bottom hose (radiator to engine) you will feel the difference in coolant temperature. With a new radiator and very cold temps the return hose will be pretty cool, sometimes even lower than your body temp.
The hotter temp you feel in summer means the coolant removes less heat from the engine so it should mean more heat dedicated to combustion.

Watch those FINGERS!

regards
Mech

[user removed]

Anytime you think of incoming air temperature, just take it to the extremes. Say 50 below 0 and 180 above. I think either one would give you problems, but I am sure the 50 below will not help your efficiency. When fuel is injected the huge increase in surface area absorbs heat. The is one of the reasons why direct injection allows an engines compression to be increased significantly and still run on regular fuel, but DI with sequential squirts cam also be done while combustion is actually occurring, which in the case of the Mazda SKYACTIV engines just coming out, allows compression ratios as high as 14 to 1 running on gasoline with no possibility of pre ignition, since there is almost no fuel in the combustion chamber before TDC.

Transonic is working on fuel heated to several hundred degrees under pressures approaching 200 atmospheres (almost 3000 PSI). The idea is to have the fuel self ignite when injected with no spark necessary like a diesel (but gasoline).

Semi hijack, my apologies.

regards
Mech

[user removed]

Originally Posted by mbrac

Yes - that is the idea - stopping tonight to get the heater core - $20 at Advanced Auto - and hope to get going on it this weekend - I'll post results and pictures - I have a netbook pc installed in the car with the ECM connected and running ODBWiz software - so I can monitor everything and log it - it's a sweet setup!

Run the heater supply hose (hot) to your additional heater core, then to the regular heater core. If the additional cooling reduces the need for the regular radiator to provide cooling then the thermostat will just close up some. Heaters are generally bypassing the thermostat anyway, which is why you normally should not turn the heater on until you get decent movement of the temp gauge.

Garages help when you leave the heater off and drive away immediately after starting the engine.

regards
Mech

[8307c4]

To all the folks who think a warm air intake improves a car's fuel economy, a warm air intake is NOT good for fuel economy, I don't give a damn what anyone says the real reason it improves anything at all is because it governs (throttles down) the car's power hence allowing it to consume less fuel but if this is the case it is high time some drivers review their driving style because it also makes it LESS efficient, meaning if you're seeing gains in fuel economy then you are driving very inefficiently, you'd be better off keeping your foot off the floor or put a brick underneath your gas pedal, that will make your car's fuel mileage increase too.

[user removed]

Originally Posted by 8307c4

To all the folks who think a warm air intake improves a car's fuel economy, a warm air intake is NOT good for fuel economy, I don't give a damn what anyone says the real reason it improves anything at all is because it governs (throttles down) the car's power hence allowing it to consume less fuel but if this is the case it is high time some drivers review their driving style because it also makes it LESS efficient, meaning if you're seeing gains in fuel economy then you are driving very inefficiently, you'd be better off keeping your foot off the floor or put a brick underneath your gas pedal, that will make your car's fuel mileage increase too.

And we should "give a damn" about what you say .

regards
Mech

[SentraSE-R]

Running a WAI through the wringer.

[California98Civic]

Originally Posted by 8307c4

To all the folks who think a warm air intake improves a car's fuel economy, a warm air intake is NOT good for fuel economy, I don't give a damn what anyone says the real reason it improves anything at all is because it governs (throttles down) the car's power hence allowing it to consume less fuel but if this is the case it is high time some drivers review their driving style because it also makes it LESS efficient, meaning if you're seeing gains in fuel economy then you are driving very inefficiently, you'd be better off keeping your foot off the floor or put a brick underneath your gas pedal, that will make your car's fuel mileage increase too.

My understanding is that the benefits, which only seem to accrue to MAP equipped cars and not MAF equipped cars, come from reduced pumping losses. Here are the results of my test on my MAP equipped car: http://ecomodder.com/forum/showthrea...tml#post233571 ...but you don't have to "give a damn" ... it won't worry me or reduce my fuel economy.

[pete c]

You can always spot an ecomodder noob when the topic of warm air intakes is brought up.

It comes from the fact that the rest of the world is trying to squeeze more power out of their engines rather than just better mpg.

To the noobs, of which I sort of am, but, been here long enough to 'get' WAI.....

CAI allows you to stuff more O2 into a cylinder for a given throttle opening. More O2 means more fuel and more power.

You might consider this more "efficient" in that you are making more power. But remember, the name of the game here is to make just enough power to push your car at a desired speed.

So, since power as a function of throttle opening, is higher with CAI, a WAI throttle must be opened further than a CAI throttle to get to the desired power output.

And since pumping losses decrease with throttle opening, the WAI will have lower pumping losses which means higher efficiency.

It requires a different way of looking at things and remembering that it all revolves around pumping losses and possibly better fuel atomization.

I am sure there is a better worded explanation somewhere around here. Perhaps someone could post a link to it.

[ConnClark]

Originally Posted by pete c

You can always spot an ecomodder noob when the topic of warm air intakes is brought up.

It comes from the fact that the rest of the world is trying to squeeze more power out of their engines rather than just better mpg.

To the noobs, of which I sort of am, but, been here long enough to 'get' WAI.....

CAI allows you to stuff more O2 into a cylinder for a given throttle opening. More O2 means more fuel and more power.

You might consider this more "efficient" in that you are making more power. But remember, the name of the game here is to make just enough power to push your car at a desired speed.

So, since power as a function of throttle opening, is higher with CAI, a WAI throttle must be opened further than a CAI throttle to get to the desired power output.

And since pumping losses decrease with throttle opening, the WAI will have lower pumping losses which means higher efficiency.

It requires a different way of looking at things and remembering that it all revolves around pumping losses and possibly better fuel atomization.

I am sure there is a better worded explanation somewhere around here. Perhaps someone could post a link to it.

Except for the fact that EGR and PCV offset pumping losses to a large degree. A colder air intake with a more closed throttle plate will increase EGR flow thus leading to more trapped mass in the cylinder which in turn reduces heat lost to the cooling system and allows more energy to be extracted from the power stroke. Also as mentioned before a cooler intake charge also reduces energy lost to the cooling system.

If you want more proof, cooled EGR bumps mileage compared to non cooled EGR.

[California98Civic]

Originally Posted by ConnClark

Except for the fact that EGR and PCV offset pumping losses to a large degree. A colder air intake with a more closed throttle plate will increase EGR flow thus leading to more trapped mass in the cylinder which in turn reduces heat lost to the cooling system and allows more energy to be extracted from the power stroke. Also as mentioned before a cooler intake charge also reduces energy lost to the cooling system.

If you want more proof, cooled EGR bumps mileage compared to non cooled EGR.

Was that last line supposed to have a link? I'd like to see it, if so. And just as an FYI for readers who might not know, not all cars have EGR. Mine does not. What this all demonstrates is the need to know your car and test for results whenever there is substantial reason for doubt about a mod.