Yeah i got a Pro-M 70mm bullet meter w/ an amsoil filter clamped on there that is 6" OD @ the base, 9" media height, 5" OD @ the top w/ a reverse cone in the top. Seems like well made filter too. This was about the largest filter that i could find w/ a 3.5" flange ID on it.

 

It might seem counter-intuitive, but a cowl hood works much the same as a ram-air hood. Due to the aerodynamics of the windshield, a high pressure region forms right at the base of the windshield, forcing air into the cowl opening on cowl induction hoods. This is one reason that stock cars have the air box opening in the cowl - higher pressure air and less drag than a ram air style hood.

As for the hot vs. cold air intake discussion, it really depends on what you're after. Warmer air will more easily vaporize fuel (liquid fuel will not burn) allowing for more complete combustion and greater efficiency. As others have already said, the tradeoff is a less dense air charge which reduces power. The density issue of the hotter intake air can be overcome by forced induction, but then knock (autoignition) becomes a concern with the higher temperatures. Cold air definitely makes more power and knock won't be a concern as much more heat goes to vaporizing the fuel before the mixture can ignite.

If anyone wants an interesting read, look up Smokey Yunick's adiabatic engine.

 

from what i have seen the intake won't matter between a CAI and open element b/c of the reasons i mentioned before and it has been proven quite a few times now on our diesels. Being that these trucks are N/A how much is the air charge being heated between the filter and the cylinders?? If we had turbos or SCs then i would worry more about the air charge temp thru using an IC as the air charge after the charger will be quite a bit hotter than it was at the filter(more so on a diesel-30psi vs 10psi) we have seen temp drops of a few hundred degrees on diesels that didn't use ICs stock and then adding one on modded trucks running around 40psi of boost. On a N/A truck there isn't much you can do to b/c the air at the filter is already very very close or right at ambient temp at the filter. there is no compressing of the air so it's not heating up. the only thing heating the air is the temp of the intake manifolds themselves. so of course if you can keep the upper intake from heating up then the air won't be as hot entering the cylinders, but will still heat up some in the lower intake which is fine for fuel atomization. All in all the intake doesn't matter.. cheapest route and just as efficient is the open element, if you truely believe that a little piece of plastic is going to make your intake air cooler then so be it and run it. truth is it really doesn't help that much from our diesel tests.

 

I just want to thank everone that contributed to this thread , hope this shuts up some of the trash talkers about open element & custom intakes , it probably won't , but i thought the test went well , thanks !!!! Lew

 

x2 Should be a sticky

Or in the FAQ section

 

I have an open element Spectre filter from Pep Boys on my Supra. I need to clean it or change it out. You know what I notice about it? It gives the car a whistle. Imagine a turbo that doesn't spool, it's just...there. But the whistle becomes audible whenever it feels like it haha.

That's what open element filters do to a car with an air flow meter. I actually want to get rid of it and go back to the stock box, but I threw my box away and haven't tried really hard to find another.

A vendor online sells cold air kits for my Supra, you drill a hole and the tubing extends the filter down through your fender well then turns it and it faces your front bumper.

 

Yea I like the whistle.. I make BOV noises with my mouth too.

 

My PSD whistles loud enough with the open element that the video camera messes up the sound. the camera can't take that high pitched whistle of goodness.

 

I really appreciate you taking the time to play around with these setups. I just am not able to agree with the hot air intakes being better.

I don't see how its better, because my truck ran worse and go worse fuel economy with the FIPK crap. I had it on my truck for quite some time and consistantly fuel mileage was low. The stock setup with the I6/460 tube and OE filter returned fuel economy to about 16 mpg city highway mix. Before that I could barely get 14 with the FIPK. I think there was some condition that was different during your test.

We had the same fuel ecnomy issue on our 97 Cobra that always maganaged mid 20s for fuel economy during normal driving and commuting. With the FIPK it got just barely over 20 mpg.

Those are my real world tests and the FIPK fails. Not to mention the fact that on the F150 the tube was mis-shaped and did not seal up at the throttle body. My friend had this same issue as well.

 

Everone has there own opinions , the test just showed that a cone filter & stock filter set up have the same air intake temp , the conditions were the same for both tests , same outside temp , drove the same road at the same speed , for the same time , both had a thermometer in the intake tube at the same place , outhers have done this test to with the same results , even a true cold air intake was the same at criusing speeds , for a stock truck a conical is not needed , but any hiperformane motor needs a breath & your not going to get that from the stock air box , a conical filter just flows alot more volume....Lew

 

You may be right about the stock vehicle part. What about the Cobra though its a higher performance vehicle and is stock, but its not the same as a regular stock Mustang.

 

All i can think of is when you replace the factory filter (even on a mustang ) with a better flowing filter it draws more air, so uses more fuel...

 

That could be, but the car also did not run nearly as well.

 

I have 94 f150 and was wondering if anybody had info on mass airflow conversion?

 

Never had that problem on a mass air car , maybe some others will chime in on that ?