Why does almost every .......

[sweetk30]

Build you see from cheep crap to 100k dollar rides insist on sucking in HOT air from under the hood with a cheep filter ?

Yep so many want cold air intakes also ?

Hell my efi sbc i put in my truck still gets its air from the core support hole next to the radiator.

Sorry question rant off . Lets discuss this more .

 

[centexk5]

Looks cooler.

 

[Polymath]

I've had people flat out refuse to believe me when I tell them that their "cold air intake" which pulls air from the hot engine bay is actually far hotter than the stock intake which pulled air from somewhere outside the car. K&N's marketing team did a damned good job.

 

[Bent77]

I put a different cleaner system on the 77 that pulls from the core support. IAT dropped 30+ degrees consistently

 

[mrk5]

When I played around with it on the C10, even just putting the intake inlet on the back side of core support behind the headlight dropped the IAT by a huge margin as compared to an old school air cleaner housing.

That said, I question whether there is a noticeable change in performance. Especially on an old mild 350.

 

[Wes Harden]

I would say that preignition would be more prevalent in hot summer driving. Esp in an old truck with much thought designed into air flow.
That said there isn't any difference between an open element air cleaner and K&N "cold air" system. How many peps are running open element air cleaners here ??? I have a few. The 77 is still factory stock air cleaner, going to keep it that way. Less hot air warm up.

 

[Blue85]

You can get something like 1% more HP for every 10 degrees F reduction. The flip side is that the longer intake tract will be more restrictive. For any properly built intake, the temperature factor is dominant. There are intakes available that seal to the hood (although how well probably varies a lot), so you can see an open filter with the hood open, but it still acts as a CAI. Depending on the airflow in the car, sometimes the underhood air temp is "not that bad" at highway speeds (where you need HP), but it's generally terrible sitting at idle (where you don't make any HP).

The aftermarket intakes aren't done solely for appearance. Some people prefer the sound, compared to an OEM intake system that is designed to quiet the engine (especially if you have a turbo or supercharger). There are cases where the OE intake is restrictive enough that swapping it out increases power, but generally only if you can draw cold air. There are exceptions to every rule, of course. Sometimes the engine swap or whatever mods means there is no factory intake that will fit.

Sometimes the aftermarket filters are dangerously poor at filtration, so do your research. Paper is fine as filter media, you just need a lot of surface area. Many an engine has been saved by a paper air filter when the intake starts sucking up water.

 

[TerryD]

You can get something like 1% more HP for every 10 degrees F reduction. The flip side is that the longer intake tract will be more restrictive. For any properly built intake, the temperature factor is dominant. There are intakes available that seal to the hood (although how well probably varies a lot), so you can see an open filter with the hood open, but it still acts as a CAI. Depending on the airflow in the car, sometimes the underhood air temp is "not that bad" at highway speeds (where you need HP), but it's generally terrible sitting at idle (where you don't make any HP).

The aftermarket intakes aren't done solely for appearance. Some people prefer the sound, compared to an OEM intake system that is designed to quiet the engine (especially if you have a turbo or supercharger). There are cases where the OE intake is restrictive enough that swapping it out increases power, but generally only if you can draw cold air. There are exceptions to every rule, of course. Sometimes the engine swap or whatever mods means there is no factory intake that will fit.

Sometimes the aftermarket filters are dangerously poor at filtration, so do your research. Paper is fine as filter media, you just need a lot of surface area. Many an engine has been saved by a paper air filter when the intake starts sucking up water.

I use the 1:10 ratio for easy math but I think it's closer to 7.5°F but anyways, the published "gains" are based on a vehicle strapped to a dyno with the hood up and MASSIVE fans clearing the hot air away.

As for need, sitting at a light like on the starting line of a drag strip, that's where you want the extra power "gains" but are actually losing power to the increased IAT. And a single pass, even at WOT won't drop the IAT noticeably due to heat sink in the inlet tract.

For my Camaro, I used an air cleaner with a larger snorkel than the stock one, adjusted the TherMac to maintain ~100°F temps and reinstalled the air riser tube from the manifold to the air cleaner housing. It's a compromise but also helps maintain economy and emissions standards.

 

[Fastereddie]

Ask gale banks about air density…haha.
It’s very important.
I try to at least use the plastic intake stuff not metal to help with heat soak. When I did @Desert_K5 swap we used the stock 2017 truck airbox that draws air from the fender inlet.
I can’t do that with Deon’s first gen, the fender to wheel well area isn’t big enough.
I do want to build some type of air dam to shroud the filter from heat though.

 

[Blue85]

View attachment 472264

But now the clothes dryer isn't hooked up?

 

[ktmoutfront]

Wait.......

I thought flipping the air cleaner lid was all that was needed, to gain the maximum horse power boosting .

 

[TerryD]

But now the clothes dryer isn't hooked up?

Its not a project car till the hardware store gets involved. LOL

 

[Desert_K5]

Ask gale banks about air density…haha.
It’s very important.
I try to at least use the plastic intake stuff not metal to help with heat soak. When I did @Desert_K5 swap we used the stock 2017 truck airbox that draws air from the fender inlet.
I can’t do that with Deon’s first gen, the fender to wheel well area isn’t big enough.
I do want to build some type of air dam to shroud the filter from heat though.

The way @Fastereddie hooked mine up is 100%. I've been through tons of silt beds 4' deep and many miles of desert. The OEM Chevy filter is almost as clean as a new one, it's crazy good.

 

[sweetk30]

Wait.......

I thought flipping the air cleaner lid was all that was needed, to gain the maximum horse power boosting .

only with a old Q-jet carb and a white wife beater shirt on .

 

[Wes Harden]

only with a old Q-jet carb and a white with mustard and grease stains wife beater shirt on .

fitfy

 

[tarussell]

Sadly most folks can’t tell the non-difference between the open element or super-trick lid-flipped air cleaners and a proper set up because all they can concentrate on is that they can hear more throttle suction noise and they equate that with added power.
It’s a mistaken mind over reality situation that they have made their minds and don’t want to hear the truth.

 

[Wes Harden]

yeah but when you can really really hear the secondaries on a Q jet open it's definitely fast then when you can't

 

[tarussell]

In high school my friend was given his grandmother’s 1970 Pontiac Catalina with a 455 and Q-jet equipped - naturally the first thing we did was flip the air cleaner lid for that wonder sound of the huge secondaries at wide open throttle.

We didn’t need the radio because that Q-jet was mak’n music that was so sweet to all our ears !
Thank God gas was cheap back then because he stayed in that skinny pedal ALL the time.
Good times!

 

[500$k5]

In high school my friend was given his grandmother’s 1970 Pontiac Catalina with a 455 and Q-jet equipped - naturally the first thing we did was flip the air cleaner lid for that wonder sound of the huge secondaries at wide open throttle.

We didn’t need the radio because that Q-jet was mak’n music that was so sweet to all our ears !
Thank God gas was cheap back then because he stayed in that skinny pedal ALL the time.
Good times!

Yep! 73 Olds 98 455 turbo 400! Soon as we were out of sight, one person flipped the air cleaner! And then, the others pulled all of the hubcaps, because we would get tired of finding them in a field somewhere!

 

[tarussell]

Yep! 73 Olds 98 455 turbo 400! Soon as we were out of sight, one person flipped the air cleaner! And then, the others pulled all of the hubcaps, because we would get tired of finding them in a field somewhere!

We had to rotate the tires about once a month due to the blistering one-wheel burn outs that seemed to always be needed - gotta love an open diff with a 2:?? something rear gear and a mountain of torque available
The beautiful part was what we called the “factory” TH400 shift kit - hold it in low and let the pressure build up to where it would manually shift into second gear with brute force ( well, brute enough for sixteen year olds ) and lat another long black streak on the road.
It was at this time that we learned to put Clorox down on the tire to create a generous amount of white smoke.

All this fun started with flipp’n the lid of the air cleaner and unleash’n all that mystical horsepower fed by ambient HOT air under the hood and lett’n that Q-jet sing them songs to us - - good times !