Modification: Warm Air Intake

[diamondlarry]

Off of the air filter box is a tube that runs toward the front of the car. This air filter tube runs parallel to the top radiator hose. the sensor is in the side of the tube near the opening. The connector may be kind of difficult to unhook. I have to pull up on the top part of the plug then use my pocket knife to push down on the other tab. Since everything runs so close to the radiator hose, you either want to let the car cool off or be real careful not to roast your hand.
Larry

[rh77]

My '99 Acura TL actually has a heater core that lies right under the air filter-box. They tell me it's there to help with startup emissions and fuel economy. There's a trap door with an open-close mechanism that draws the heated air under certain conditions. Some folks looking to add more horsepower actually removed it but found themselves with a big mess of coolant and a difficult re-route. Long-story-short, folks could find cars with this and purchase this device (or go to a junkyard)or rig up a heater core that heats the air using the coolant/anti-freeze and work it into the filter or pre-filter area.

RH77

[diamondlarry]

A friend of mine did something like that to his Saturn. He took a used heater core and modified his airbox to fit it in so he would still have his air filtered. I'll have to ask him how it turned out.

[rh77]

With the cylinder de-activation debunked, my focus has now been on drawing warmer air into the intake. Basically I routed it from the exhaust-header area into the airbox. Today's outside temp was 67. My datalogger showed a range of 80-150 deg. F., with an increasing negative Long-Term Fuel Trim percentage leaning out the mixture -- which will hopefully yield better economy. I honestly haven't noticed any seat-of-the-pants power loss, but the thing is loud at WOT!

Has anyone found a sweet-spot for temp? I assume the higher, the better -- but too hot probably means too lean, or would the ECU take car of it?

-RH77

[SVOboy]

If you go too hot, like larry did to find the max, the car will throw a check engine light or you'll be able to tell from crappy running, though I doubt you can get that hot with actual air.

[rh77]

The results are in from the warm-air intake...31.1 mpg, which is a huge improvement over 26. To keep the test scientific, I didn't modify my driving style, hit redline a few times and even had 2 passengers during one trip. My cruising speed on the highway was 70. The datalogger shows the difference -- Long-Term fuel trim went into the negative percentages with the increase in intake air temp (leaner mix, less fuel).

The setup draws air from the "Y" at the exhaust manifold using a clothes-dryer duct, into the airbox. Temps ranged anywhere from 90-150F.

So, with the understanding that air is a poor conductor of heat, I'd like to tap into the coolant line with a heater core closer to the intake point, to maximize the effect. Thanks!

-RH77

[SVOboy]

Damn! Take some pictures and do a little write up and post this over in the experiment section. I can host all the pictures you need! Wow, that's exciting, I might go for this since it gave such a huge increase without a whole hell of a lot of difference in temperature (compared to 240 degrees witht he resistors). Feel any power difference perchance?

[rh77]

Now my friends call me the Half-A$$ mechanic, since I kinda throw things together sometimes, and never have the right tools. My wife has the digital camera out-of-town this weekend, so I can't take any pics right now.

Just to see if worked, I ran the duct to header and fastened it there with coat hanger and holiday wire (you know that stuff that holds the holiday ribbon on the wreath). From my cold-air intake, I had a piece of PVC that was oval-shaped at the end that fit into the airbox. I duct-taped the pipe to the vent duct, and put a screw through the elongated end of the pipe, into the airbox (it kept dropping out). The airbox has some extra room as I have a cone-shaped K&N filter.

Long-story short, I travel for a living. Monday morning I leave town and then get back Thursday night. I have a video camera that takes still-pictures, maybe I can get that to work today...but getting them into the laptop is a grey area. I'll see what I can do.

-RH77

[SVOboy]

Sweet, excited to see this. Given your huge gains I'm thinking I'll put this as my number one next modification, in front of all the other crap.

[diamondlarry]

If I can figure out how to do it, I'm going to get some dryer vent tubing and try to draw some warm air from around my exhaust manifold. My thought on doing this is this: I know the ECU is leaning out the mix because of the resistors, but I'm thinking that the warm air will help the fuel that IS being injected to burn more efficiently.