Intake modification- 08 Expedition

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joezek

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I recently just rebuilt my engine in the truck. Slightly upgraded the cams and exhaust while it was apart. Today I changed up the intake a little bit. The stock intake was nice and quiet, but the short path from the airbox to the throttle body was full of many J-tubes and other types of noise cancelling areas. It really just looked terrible and blocked the view/access to a lot of the engine. The good thing about the factory setup though is that the airbox is piped directly into the left fender well and gets cold outside air, not the 150+ degree air from behind the radiator. I would think the stock setup was slowing down the airflow while making it silent. The new setup is a direct short path from the filter to engine with not much time to absorb any heat.

Basically I just bought two 3.5" rubber coupling made for turbo intakes (one straight coupling, one is 60 degree). Also needed a foot long straight piece of 3.5" aluminum tube and two more hose clamps. I pulled the stock plastic piece out and replaced with the two couplings and tube. I also replaced the factory air filter with an AEM Dryflow. It's supposed to flow much more volume than stock, and it's cleanable, and doesn't need the red sticky spray on it that usually gets on your MAF and clogs it. I got the straight pipe and coupling from Amazon and the 60 degree coupling from Siliconeintakes.com. I probably could've gotten both couplings there, but the first one I bought was all they carried on Amazon and didn't fit (45 degree). Thought I'd be able to buy from all one source but that didn't work. Anyways, total $ was probably less than $120 and I still get cold outside air, and a cleanable high flow filter. The filter was AEM 28-20385, about $69. My air inlet temp gauge is showing the same or sometimes 1 degree higher than the outside air temp on the dash.

I can't say I've noticed any obvious performance difference, if there was any it's probably only a few HP. But now I can hear the intake any time I'm stepping on the gas, but it's not obnoxious. I like being able to reuse this filter and clean it as often as I want without going to the store and buying one, half the time leaving with the wrong one....lol20220705_160900.jpg20220705_160939.jpg20220705_160944.jpg
 

mkbruin

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Thank you for this. I am looking to do exactly the same and will have to steal this from you.
 
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I had a K&N intake on my '08 for about six months. It was a lot louder, but not any faster. I think a modded V10 tb (or aftermarket equivalent) and a tuner are pretty much required for improved intake flow.
 
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joezek

joezek

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Yeah, the design of the truck intake on the 5.4 engine is all about low RPM torque. Even a bigger TB still won't make much of a difference. The intake itself is such a weird design that it's causing the engine to build low end torque, but no real power above around 4300 RPM. The main benefit of what I did was make a more direct path for the air to stay cool before entering the intake, and add a cleanable filter. This is the AEM Dryflow air filter, which doesn't require the cleaning kit and red filter spray. Now I won't need to buy a new filter all the time.
 

Logan97

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Yeah, the design of the truck intake on the 5.4 engine is all about low RPM torque. Even a bigger TB still won't make much of a difference. The intake itself is such a weird design that it's causing the engine to build low end torque, but no real power above around 4300 RPM. The main benefit of what I did was make a more direct path for the air to stay cool before entering the intake, and add a cleanable filter. This is the AEM Dryflow air filter, which doesn't require the cleaning kit and red filter spray. Now I won't need to buy a new filter all the time.
How long did it take to get that coupler from siliconeintakes.com? I ordered it Friday and it said 2-3 days but my order still says pending. I contacted them and they haven't responded.
 
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joezek

joezek

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Just saw your message. It only took a few days to get here though.
 
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