Best (performancewise) air cleaner kit? - Harley Forum

#1 12-19-2008, 12:35 AM

I have a beautiful 2003 FXST with a Screaming Eagle air cleaner kit and Screaming Eagle Shotguns. I noticed a small performance increase when I did that but I want to know..performancewise, what is the very best air intake system available. I read several years ago about Zippers' kit. The performance increase when it was installed was pretty good. But what about now? What is the best bolt of system that I can buy?

frisco-rigid · #2 12-22-2008, 01:46 AM

Increased airflow is what most Air-intake sellers are promising..
Air-flow usually equals more power..

I bet Zippers kit is superb and of course, comparing it to whatever stock AC unit it replaced, I'm not surprised it shows good air flow & HP increase..

Other than that, perhaps S&S with their Tear-drop AC cover with the air-flow TIT that protrudes into the airflow might be very efficient cuz of some kinda airflow dynamics,, at least that used to be the common theory/guess..

But I want you to remember something,, the airflow is only as good as the exposure of the air filter to the world..

In-other-words-- if an air cleaners filter is 1.75" wide by 20" in circumference it's exposure to the air is 35 sq. in. and pleating only gives more Filtering area NOT more air-intake area.. More sq. in. equals more flow..

I have a shelf full of air cleaners and filters.. Old stock HD Linkert, Pan and shovel,, S&S, Mikuni and many aftermarket.. I can only say which ones Don't flow as well..
I now run the Round Ram-flow AC/filter on my 93", 120" and the 127"..
It's entire face is exposed to the world..

There are a couple kits with an "Air-horn" built into the backing plate behind the filter, they might be good too.. Kinda like a velocity stack..

Other than the S&S with the cover that has the air directing TiT there are No majically efficient units.. More flow is the prize..

If you don't know what the S&S unit or my unit looks like I can send you a photo..
frisco-rigid@mchsi.com

Have a ball

milindh · #3 12-22-2008, 03:30 PM

Hey Joel

I agree with most of what Frisco says. Good advice.

The thing about your basic Stage One SE mods like you have Joel is that they usually have enough built in restriction so that you don't have to mess with the jetting of your carb too much. Harley could have easily built in more flow into their stock A/C and exhaust and gotten more power. Could they have built their SE stuff to flow better ? Absolutely ! It's not rocket science here. If you ask a Harley PR guy they'll tell you that the stock set up is to comply with EPA limits for noise and pollution. Maybe but since the number one and two mods for any Harley are the ones you made I'm thinking the biggest reason they make the weanie A/C and pipes are so they can sell you cooler ones later. You know, to express your "individuality."

"That'll be $1500...Thank You."

Put in a super flowing A/C unit and less restrictive pipes and you'll have to re-jet your carb for sure but that's not a bad thing at all. You'll get a bit more power and with the rejetting your bike will run better and cooler all around. All good. Going with just a higher flowing A/C unit will give you a little better performance than your SE and a lot better than the stocker but not worth the bucks, in my opinion, since you have a fairly mild engine right now. You'll get a lot more flow available but only a little more go.

Better to save your money in case you are asked to bail out some more banks or poorly run corporations. That's what they mean by, "Give to the poor." Isn't it?

rjrivero · #4 12-23-2008, 10:01 PM

Quote:

Originally Posted by njoelhickson

I have a beautiful 2003 FXST with a Screaming Eagle air cleaner kit and Screaming Eagle Shotguns. I noticed a small performance increase when I did that but I want to know..performancewise, what is the very best air intake system available. I read several years ago about Zippers' kit. The performance increase when it was installed was pretty good. But what about now? What is the best bolt of system that I can buy?

The best performance air cleaner you can buy is one attached to this slipfit spinner muffler.

Link Here.

#5 12-28-2008, 12:18 AM

Thanks for your replies so far. I've been looking at Harley's Heavy Breather intake...thoughts? Better than the SE Stage 1 kit? And is it better enough to justify the cost?

botzman · #6 12-29-2008, 11:45 AM

Not to steal the thread but anyone ever use one of these? Considering for my new TC. The dual intake ports up front lead me to believe it would push some nice air in. I realize the wide open elements are the best as Frisco said but I just cant stand the look. Botz

frisco-rigid · #7 12-29-2008, 01:54 PM

Hey Botz

You know,,, I'm not really that sure that the most wide open element is the best,, I'm just guessing and using my common sense..
It makes sense to me that if the only restiction to "Intake" of air is the actual opening (area) of the carbs mouth then it stands to reason, to me, that the most Open Un-restricted element would be best..

So I use the most Open that I've found..

Now, I'll bet a dime to a doughnut that 99.99% of our motors are not able to suck in more air than the run-of-the-mill AC element can provide BUT I just want to hedge that bet, dig-it..!!

Here's something to ponder---- the example I gave in the previous post of the element with 35 sq. inches is an S&S G element, still with me.?
The opening (mouth) of the S&S G carb is 2.16" making the area of that opening 3.66" (pi x r2),,,,,,, 10 x's smaller than the area (square inches) available in the element..

Sooo, one has to ask, will the area of that carbs mouth ever be able over-whelm the area of the matching element------I don't know..
But one has to consider that at higher RPM's it just might..

I don't know what's best, I can only relay my experience and keep on tryin to find what's best for me..!!
Yeah Baby..

Spade5 · #8 12-29-2008, 02:32 PM

Interesting points Mr. Frisco. I am curious, is the 35 sq. inches for the S&S the total filter area or the area that air can pass through? I guess what I am saying is the air can only go through the spaces between the filter media and how the heck would you measure that. Maximum flow rate at one atmosphere of pressure maybe.

I have no clue as to how big a molecule of air is but I am guessing it must be pretty small in relation to the spaces between the filter media.

I think what you said about what works best for the individual probably wins the prize.

frisco-rigid · #9 12-30-2008, 01:25 AM

Hi Spade

Yes of course, the total area of the filter exposed to the world..

Diff filter media has an important role also but I only addressed the "doorway" that the air must go through..

Yes again---- in the 3 years I've been on here I've stressed the fact that Nobody Knows whats best for anybody elses sickle,, we can offer suggestions based on our own First-Hand experience but then it's up to the "operator" to find what's Best for His/Her motorsickle..

Yeah Baby..!

botzman · #10 12-30-2008, 07:33 PM

Frisoc,

Thanks for the input. I got what your saying. Gonna have to just test it out and see how well it works. Botz