Best Performing Air Filters

[303 Mopar]

The Engine Masters series on the Motor Trend channel (soon on YouTube) did some testing to know if a car's high-performance air filter makes a difference, or if a small filter is killing horsepower.  The testing included 19 different combinations of filter sizes and styles including paper elements, K&N filters, stock housings, dual-snorkle housings, velocity stacks, filtered lids, and even a salad bowl.  The test engine was a 750-horsepower, 496ci big-block Chevy but it is relevant to any engine. They found that the airflow straight down the carb was much more important than airflow across the carb.  The worst air filters caused the most HP loss were the smaller air filters.  Our beloved dual snorkel zapped over 50 hp, but flip the lid and it only caused about 12 HP loss.   The best air filters were velocity stacks that actually increased HP a small amount over an open carb.

[Chryco Psycho]

weird how the velocity stack is at the bottom & top of the list

[Bullitt-]

weird how the velocity stack is at the bottom & top of the list

The upper example lists as "Foam Velocity Stack"
The lower example lists as "Open Velocity Stack"

I wonder how my '68 box from a 383 Road Runner would fair.. It's open all the way around.

[Chryco Psycho]

I see that but the foam cuts the flow in 1/2 

[1 Wild R/T]

73 Dad bought a new Chrysler actually ordered it while we were living in Turkey & picked it up in Bayone NJ when we returned.... Drove it across the US to his new Command @ Nellis AFB in Las Vegas, only broke down twice along the way, once in Scranton Pa & once in Ft Collins Co.....  It was 100% slow pig... Once we were in Vegas I flipped the air cleaner lid & didn't say a word.... Shoulda seen the look on his face the next time he hit the throttle....   It wasn't any faster but it sure sounded like it was....

[RUNCHARGER]

Yes: That was the first mod back in the day. I  didn't think it added anything but noise, wrong I guess. I have always thought the oval Mopar aircleaners were probably a pretty good design, no data to back it up though.
My brother was a mechanic at the Chrysler dealer in the glory years, he always added a second snorkle to whatever 2 barrel car Dad owned back in those days.

[Chryco Psycho]

we tested a 6 pack base on the dyno , it gained HP just have the base direct the airflow into the carbs , the filter has a lot of surface area but I bet it would flow more if it was doubled up .

[Brads70]

After helping my buddy Mike with his 71 Challenger equipped with a shaker..... What a pain to work on, I bet they flow air terribly?  I can't say I have any big urge to own a shaker because of how much a pain they are to work on.

[fc7cuda]

After helping my buddy Mike with his 71 Challenger equipped with a shaker..... What a pain to work on, I bet they flow air terribly?  I can't say I have any big urge to own a shaker because of how much a pain they are to work on.

Yeah, it's a trade off - looks for coolness 

[RUNCHARGER]

Shakers are a pain alright. I always have a 1/4 drive setup in the console too in case I have to pull it all off when on the road. They probably flow okay for moderate performance though, The Six Pack and Hemi setups use the large filter and there is a reasonable route for the air to get in (well inn the front anyway).

[kawahonda]

Searched for Hile but couldn't find. Would a K&N filter add more power in the stock air housing over a paper element?

[Strawdawg]

Searched for Hile but couldn't find. Would a K&N filter add more power in the stock air housing over a paper element?

I would guess a gain of 1 hp would be lucky, but, it will add a lot more fine dust to the engine.

[RUNCHARGER]

I agree: I have seen dust inside K&N's enough times that I pull them off anything I buy that has one.

[61K T/A]

Here's the KN I'm using now. If you choose to use a cotton filter make sure you use the pre filter.

[bennydodge]

After helping my buddy Mike with his 71 Challenger equipped with a shaker..... What a pain to work on, I bet they flow air terribly?  I can't say I have any big urge to own a shaker because of how much a pain they are to work on.

Yeah, it's a trade off - looks for coolness 

Anytime the engine ingests air outside of the engine compartment it's good. Yes a pain to get on/off for sure but I'm betting the shaker cars made more power than the standard E-body hi-po dual snorkel air cleaner...