Ideal HAI question

[busypaws]

I have an 80% grill block, Home Depot Lawn edging air dam, piece of coroplast acting as a partial engine bay belly pan. I've also removed all the air intake tubing prior to the air filter box. So the air filter box is just sucking air from 6 inches or so behind the radiator. With this I run air intake temps about 20 warmer then the outside air after engine warms up. When my cooling fan cuts on I can see 30-40 degrees warmer (100-110). When I get above 110 I do start to ping when I have a throttle position greater then 25 or so. I have gotten my best trip mileage when it's warm like this -- Don't know if it is HAI or I'm getting better at hypermilling. Just my experience (No experimental data)

[Floordford]

So yesterday I tried an idea. I got aluminum rain gutter parts and tried to make a 90 degree air channel that would come from the lower radiator area and aim it at my air filter. But it didnt work out like I wanted. I have my ABS block, upper radiator hose and A/C lines that get in the way.

I did however block off a big fender hole that lets in cool outside air and I took of the K&N provided shield that insulates the filter from hot air. So now its an open filter that will suck under hood heat. Plus I sealed the gaps around the passenger headlight so that the hood doesnt scoop cool air onto the filter.

The testing grounds is a 158mile down and back from Nashville to the Alabama state line. All highway and close to 2.5 hours of driving. I got 32mpg Friday when I made the trip so if these mods are worth anything ill hope to see it Monday when I make the same trip.

BTW, my intake temp Friday when making that trip was 75 degrees with 185 coolant temps. Ill note the modified intake temp.

Oh, I also took my passenger mirror off. So Mondays testing will have to consider that too.

[jakobnev]

How about a variable temperature air intake? It gives you warm air on low load and cold air on high load.

[Floordford]

Originally Posted by jakobnev

How about a variable temperature air intake? It gives you warm air on low load and cold air on high load.

Im sure it could be done with some creative actuators that help channel or block cool or hot air. Then controlled by an engine load kind of detector or vacuum actuators. But would the price of doing all that be worth it in the end? Maybe, if parts to build it could be found really cheap.

[California98Civic]

Originally Posted by Joenavy85

I don't think a HAI will help a vehicle with a MAF sensor

The MAF sensor seems not to work, judging from tests people have tried here. I run a WAI with my MAP sensor. I have tested fairly rigorously in an A-B-A format (see link in my signature for test results). I have seen temps as high as the 130s without knock. I saw a significant FE gain.

Originally Posted by Joenavy85

Higher intake temp = less dense air charge = lower O2 content = less fuel injected = more throttle required for same amount of power = lower pumping and throttling losses = better efficiency. My Jeep starts to knock around 140*, my girlfriend's Focus starts to knock around 150-155* (at least that's when the knock sensor says it's knocking)

Joenavy85 does it again! I think he is completely correct on why a WAI works with a MAP sensor. The design I use gets warm air from above the exhaust manifold and catalytic converter. (Pictured in my avatar.)

Good luck!

[jakobnev]

Floordford: Or just a simple flap controlled from a simple wire from your simple throttle. (Advanced solutions are only good for engineers payed by the hour.)

[Floordford]

California98civic: So you are saying that guys with the older MAP sensors will benefit more over MAF style?

[California98Civic]

Originally Posted by Floordford

California98civic: So you are saying that guys with the older MAP sensors will benefit more over MAF style?

I don't know why, but the results that people here seem to have produced--myself included--show that. And one further: those with a MAF sensor cars might see a penalty while the MAP sensor cars benefit. I am confident of my results, but I am also confident of continuing skepticism by some.

[Floordford]

Interesting. Maybe its because MAP systems go off of a predetermined set of parameters while MAF style systems do more adjusting to more specific conditions.

[Phantom]

MAF systems should still see less air and add less fuel, the reason why is the MAF is just a heated resistor that tries to maintain a specific temp the additional voltage needed to maintain the voltage tells it how much air it is seeing. If the incoming air is hotter then there is less voltage needed to maintain the MAF resulting in a lower value.

On Speed Density (uses volumetric efficacy tables) systems that use the MAP to determine the LBs of air being consumed still accounts for the reading of the IAT in its calculations. Changing the value of the IAT sensor might work shortly but the O2 sensor will correct for this but it could allow more timing to be added since it is thinking the temp is lower. If values are to far off the PCM can use other tables is active to calculate the amount of incoming air such as the "Default Air Table".