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cold air intake off the heater vent in hood

Bart

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Dec 12, 2001
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Buffalo Gap, Texas
Somewhere, sometime, I saw where someone had made a cold air intake using part of the heater ducting on the passenger side hood louvers. Anyone remember this? It involved the 90ish mustang efi system. Lots of "some" in this ;D
 

Steve83

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Bad idea - it's also a RAIN-air intake. And a dirt-air intake, and a bug-air intake, and a whatever-else-falls-on/in-it intake. There's a reason all automotive engine intakes are designed for the air to move UP as it enters.
 

markw

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Bart, I have one of those BCB kits I never used. Powder coated silver/grey if you're interested I'd consider selling it. Mark
 

pcf_mark

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Jun 11, 2010
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From a performance perspective it sounds great. Pick up engine air that is cool and dense nowhere near hot engine bits. Way above water or dirt thrown by tires of other vehicles. You would need to design it to accommodate rain / snow that may fall from above. If you run a carb you may also get fuel smell inside the cabin.
 

hossbronco

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Bad idea - it's also a RAIN-air intake. And a dirt-air intake, and a bug-air intake, and a whatever-else-falls-on/in-it intake. There's a reason all automotive engine intakes are designed for the air to move UP as it enters.
The BC Broncos box is designed to let the rain drop out (I can’t confirm how well that feature works, but it should), and the bugs are more likely to come in the grill than the top of the hood, though the filter will stop them either way. I also like that for high water the top of the cowl is a better place to pull air than behind the grill, and there’s typically less dust there as well.
 

Steve83

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The BC Broncos box is designed to let the rain drop out...
All filter boxes are designed to let water out. But most of them are downstream of an air duct system that excludes rain, anyway. It's better to just not let the rain in, than to let it out.
...the bugs are more likely to come in the grill than the top of the hood, though the filter will stop them either way.
So if they're 75% likely to hit the grill, and 25% likely to come in the hood vent, it'll take 3x as long for bugs to build up on that filter than on the grill. The difference is: when they build up on the grill, the engine doesn't starve for air. If the filter is what's stopping the bugs, you'll be changing or cleaning it pretty frequently compared to one that takes air in from a better location.
...for high water the top of the cowl is a better place to pull air than behind the grill...
If that were true, that's where most vehicles would pull air from. They don't because it's not. A vehicle with an underhood air intake can be driven with the hood underwater as long as it's moving fast enough to push a wake that gives it traction. But not one that takes in air through the top of the hood.

 

hossbronco

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So much faulty logic here. At least look at the design before you bash it. The filter is in a box on the fender. I’d say it’s pretty protected from the elements.

And yes, there are a ton of vehicles that pull air in through the hood. That alone doesn’t mean it’s a good design or a bad design.
 

jamesroney

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1. Cowl Induction.
2. Shaker Hood.
3. Ram Air Hood.
4. NACA duct hood.

If 75% of the bugs hit the grill, then 25% don't hit the grill. Of that 25%, 95% hit the windshield and 4.9% hit the mirrors. This leaves 0.1% of 25% available to get to the filter. Since there are zero vertical surfaces, this leaves zero dead bugs available to fall into the filter.

The reason why manufacturers don't pull from the high pressure location on the cowl is...because they do.
 

Broncobowsher

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Most don't pull from the cowl because the induction noise isolation from the cabin. Doing intake on the cowl of most cars would be horrible for noise.
Most cars do pull air from a high pressure at the top of the grill. Pretty common these days.
 

JKH67302

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Apr 25, 2009
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I have this box in my rig. It's a two chambered design so in theory water or even heavier dirt would fall out prior to getting into the filter chamber. I don't like the filter that came with it and I can't find what OTC paper filters that BC says will work. If anyone knows let me know!

I do plan to swap out the supplied oiled filter with an AEM dry filter and for good measure I might put a filter wrap on it to help with any worry about water and help in extreme enviroments with an initial barrier to dirt. I think you would have to have a very very high rate/very short duration rainfall event for it to make it to the filter, and you would probably have to be parked when it happened. However, even if this was still concern it would be easy to modify the first chamber to drain faster. I think the dirt and debris risk is the same as any filter box in any common OEM configuration.


James

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hossbronco

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Another thing that I don’t love is that you have to reduce to 3 inch tubing/hose before the box. However, it looks like there’s plenty of room to drill it out to 4 inches, though filter size may be an issue.
 
Last edited:

JKH67302

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Another thing that I don’t love is that you have to reduce to 3 inch tubing/hose before the box. However, it looks like there’s plenty of room to drill it out to 4 inches, though filter size may be an issue.
Yes filter size is an issue. The MAF housing goes inside the box too. Finding a dry filter has been tough. I use the stock Explorer EFI components so the intake tube size was not an issue for me.

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lagbolt

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Jul 18, 2012
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With the BCB box do you have to eliminate the heater or do they share the inlet?


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hossbronco

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It replaces the heater inlet. It works well with the Vintage Air A/C & heater box.
 
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