Warm air intake on a Focus....

[mbrac]

so I'm going to get back on my project tonight - by piping in the warm air into the K & N filter - using 2 different approaches (hopefully - pictures tomorrow). One 2" line will be coming from close to the exhause mainfold - the other coming from behind the radiator - hoping to get some nice warm intake temperatures from these 2 sources - but the results will be from the mpg - so I'll be logging everything on the netbook - so hang in there - hopefully pictures tomorrow - and maybe even the results from driving to work - approx 30 miles.

[MichaelRTJ]

Is this a serious question? A *warm* air intake? You'll be dumping in unnecessary fuel, and burning too rich. That'll lower your fuel economy, not raise it. Hot air is easier for your while to drive through due to the thinner air, but cold air gives denser, more oxygen rich air to your engine.

[ConnClark]

Originally Posted by MichaelRTJ

Is this a serious question? A *warm* air intake? You'll be dumping in unnecessary fuel, and burning too rich. That'll lower your fuel economy, not raise it. Hot air is easier for your while to drive through due to the thinner air, but cold air gives denser, more oxygen rich air to your engine.

This is a mod that people swear by on here. I believe the main theory people go by is that it aids in atomization and vaporization of the fuel allowing it to burn more completely.

If you have a properly functioning ECU and O2 sensor, it shouldn't run rich because the ECU will lean out the mixture.

However there are other downsides to doing a warm air intake. One significant one is that it increases the temperature of the combustion gases and thus increases heat rejection to the cooling system. This leaves less energy in the combustion gases to be recovered as power. Another problem with increased temperature of combustion gases is it increases NOx emissions.

I have serious doubts that the positives will out weigh the negatives and only see a warm air intake as a means to warm up an engine quicker.

[MichaelRTJ]

Wow, I've never heard of it. Surely the cons out weigh the pros. The engine would also get hot easier, requiring the cooling system to work even harder. So many things that I see wrong with this. Warm fuel is great, and it seems like he is using this WAI as a lazy way to get warmer fuel.

[Focus-Ak]

On cars used primarily for short trips, a WAI helps with faster warm-ups, which gives low idle speeds earlier in a trip. Especially when combined with hypermiling techniques, this improves per-tank or per-trip mileage.

[MichaelRTJ]

I could see the benefit on a very short trip, or a relatively short on a cold winter day. But other than that, it doesn't seem to have any advantages.

[California98Civic]

Originally Posted by MichaelRTJ

I could see the benefit on a very short trip, or a relatively short on a cold winter day. But other than that, it doesn't seem to have any advantages.

IDK if this has come up in this thread, but a standard line here has been that a WAI reduces pumping losses. The ECU adjusts AFR, so the mix won't become lean as the warmer, thinner air gets pumped into the engine. But less mass of air means less fuel too... that means you get less fuel/air at a given throttle position. Therefore to accomplish the same power you open the throttleplate further, reducing the parasitic losses caused by the engine trying to suck air/fuel in past the throttle plate.

So the warmer the engine, the warmer the air, the better the reduction in pumping losses. Therefore, I'd guess short trips will not see a benefit, unless IAT climbs high, fast, somehow.

IDK if a WAI can help warmups... maybe?

[Daox]

When I tested it, it didn't really help a noticeable amount.

http://ecomodder.com/forum/showthrea...-up-11471.html