Open Air Filters vs. Covered Air Filters

[seabiz]

What are the benefits and drawbacks of both kinds; i.e. AN Big Sucker (covered) vs. AN Derby Big Sucker (open) w/ regards to rain, air flow, etc.

[Sloufoot]

What are the benefits and drawbacks of both kinds; i.e. AN Big Sucker (covered) vs. AN Derby Big Sucker (open) w/ regards to rain, air flow, etc.

Most of the advantage comes from pulling in more cool air rather than the hot air off the engine. Cold air is more dense, & contains more oxy per cu ft.
The rain can be overcome by a rain cover. I have one from K&N. They will stop most, but not all water.

[seabiz]

I had a harley tech tell me the open ACs were NG for the motor. Too much dirt, rain, etc gets into the motor. Too much turbulent air flow so you'd never have a good tune. Too much weight on the throttle body and it would break.
What say you guys out there?

[Phu Cat]

Too much weight on the throttle body

While air does have weight, no matter how small, it will never effect the operation of the throttle body.

If a certain configuration of AC put too much weight on the throttle body, it must moving a LOT more air. Every racer in the country would be using it.

Personally, I suspect AC covers are just to dress up what will become unattractive with time.

PC

[Trent]

I had a harley tech tell me the open ACs were NG for the motor. Too much dirt, rain, etc gets into the motor. Too much turbulent air flow so you'd never have a good tune. Too much weight on the throttle body and it would break.
What say you guys out there?

My favorite HD tech loves 'em. It is what he has on his bikes. When I first did mods, I put on a Ness big Sucker...seemed to work fine. 4 months ago I took that off and put on one of the new Screamin' Eagle Extreme Breather just because it looked way better than the Ness, and sucked in air from the front also, not just the sides. Increased power and lowered the tone of my exhaust even more from the extra air going in.. Just read in American Iron a coupla months ago that changing from stock to SE Extreme Breather will add 5 to 8 horsepower immediately. True or not?...Dunno...I keep a rain sock in my lower fairing to slip on if it rains. I am a fan of the open AC's..have had zero issues for 22,000 miles.

[Sloufoot]

I had a harley tech tell me the open ACs were NG for the motor. Too much dirt, rain, etc gets into the motor. Too much turbulent air flow so you'd never have a good tune. Too much weight on the throttle body and it would break.
What say you guys out there?

How does less weigh more ??? Only if you are going to use the type with the air horn bending forward. That big chrome cover with the steel backing plate, & a steel backed & topped filter isn't lite !!
Sounds like a "Tech" has been smoking the wrong tobacco !!
The new air filters are designed to cut the turbulence out as to flow more CFM at most given RPM ranges.
I bet he doesn't even like the new chrome muffler bearings !!

[eighty80]

How does less weigh more ??? Only if you are going to use the type with the air horn bending forward. That big chrome cover with the steel backing plate, & a steel backed & topped filter isn't lite !!
Sounds like a "Tech" has been smoking the wrong tobacco !!
The new air filters are designed to cut the turbulence out as to flow more CFM at most given RPM ranges.
I bet he doesn't even like the new chrome muffler bearings !!

I sure don't!! Mine pitted right away. HD said it's normal. I changed to bushings like they used to be.