Alternate Radiator Locations

[Philip1]

air is air but computers are not some cars computers calculate air density by temperature on these cars a hot air intake will improve milage. If a car uses an air flow meter a hot air intake probably won't help. Before you say my theory is flawed I will say Look at my gaslog. I agree that cold air makes more power but on some cars Hot air makes more milage. On my car there is a map sensor and an intake temp sensor I installed a hot air intake (140f usually) and saw a 10mpg increase, I actually discovered the change when it fell off and temps fell to 78f. the difference between 24 and 34mpg in my car. Like always YMMV

[GasSavers_maximilian]

Originally Posted by philip1

air is air but computers are not some cars computers calculate air density by temperature on these cars a hot air intake will improve milage. If a car uses an air flow meter a hot air intake probably won't help.

I admit to being a little fuzzy on the particulars (especially since not all cars follow the same system), but doesn't the O2 sensor influence air intake settings as well? The idea is to try and maintain a stoichiometric fuel/air mixture so the catalytic converter can work (and minimize NOx emissions...I think), right?

Anybody have an idea how the different sensors interact in the control loop?

[Philip1]

it does have a huge influence but at the same time hot air on my car affects timing oddly the MAP sensor on my car only covers idle and the WBo2 and IAT take care of the rest. Think about this a HAI will simulate driving through the desert and hot air is less dense needing less fuel to reach 14.7:1 ratio. Talking about power here is kind of pointless since a real hypermiler uses as little throttle as possible.

[GasSavers_maximilian]

Originally Posted by philip1

Think about this a HAI will simulate driving through the desert and hot air is less dense needing less fuel to reach 14.7:1 ratio.

I think of it as needing more air to reach the ratio for a given amount of fuel. Hey, different strokes.

[GasSavers_maximilian]

Let's assume that WAI does indeed cause the computer to gulp in more air, and further that the reduction in resistance from the more fully opened valve leads to a net energy gain even though more air is being pumped.

If that's the primary cause of efficiency improvements, it leads to an obvious design change: the air inlet valve. One that has less resistance at low levels of airflow. If it can matter so much, why hasn't been optimized previously? I can think of a couple ways of doing it just off the top of my head, so it can't be because it's impossible. Normally, I am hugely distrustful of "if it could've been done it would've been" arguments, but it's still a valid concern. That makes me wonder if indeed other effects are coming into play. The only air valve I've ever seen up close was for a DeLorean, and that sucker would've had much higher resistance at small opening distances. It had a movable disc (the name escapes me...diaphragm valve?) so air needed to turn a couple pretty sharp bends when mostly closed. Maybe given the way most people drive the benefits wouldn't be as great? Hypermilers do tend to drive at the lowest end of the power curve a lot more than ordinary folks. That might explain such a design oversight.

[Jay2TheRescue]

Originally Posted by maximilian

The only air valve I've ever seen up close was for a DeLorean, and that sucker would've had much higher resistance at small opening distances. It had a movable disc (the name escapes me...diaphragm valve?) so air needed to turn a couple pretty sharp bends when mostly closed. Maybe given the way most people drive the benefits wouldn't be as great? Hypermilers do tend to drive at the lowest end of the power curve a lot more than ordinary folks. That might explain such a design oversight.

If I remember correctly DMC used Ford engines & powertrains. What you saw most likely was also placed in a Mustang and/or Cougar.

-Jay

[GasSavers_maximilian]

Apparently they used a Volvo engine. Not that it really matters too much for this discussion. I hate DeLoreans anyway.

[Philip1]

I think the main reason designers don't think about low rpm as much as we'd like is HP numbers sell. For the most part you need to spin the engine fast to make those numbers. My opinion on the throttle is a twin door affair so the air entering the engine always enters in the middle of the TB. If you were to combine that with a small plenum and runner intake you could effectively have the ideal milage engine.

[theholycow]

Nearly everything on a car in the showroom is a design compromise -- designed to sell to the most people possible. That means power, excitement, noise, high RPM...at least from our point of view. If you ask on a high-performance forum, they'll tell you that everything comes set up for economy, boredom, quiet, low RPM. Either way, designs are also compromised for cost, reliability/longevity in all conditions with all drivers and driving styles, repairability (well, maybe not anymore), standards-compliance, regulatory compliance, aesthetics, and any number of other factors.

[GasSavers_NovaResource]

Fuel economy is important to car manufacturers. People want more fuel efficenet cars and the car companies must meet CAFE fuel economy standards.

So if warm air was more fuel efficient then why then do all car manufactures have the factor inlets OUTSIDE the engine compartment in an area where it could breathe in cool air? If warm are was more fuel efficient they would have the air intake inside the engine compartment to get warm air. Why spend the extra money to create an intake tract that breathes in cool air?