Hello, I am planning on purchasing a new air cleaner/filter system for my 09 XL1200C Sportster. The guy at Arlen Ness (I don't think it was Arlen himself) said that with the Big Sucker I there would be no need for any ECU/fuel tuning necessary. The HD website indicates if you get the Screamin Eagle the bike will need a trip to the shop. The Screamin Eagle is a little more expensive up front and a trip to the dealer wont be cheap either. With that in mind I'm leaning towards the Big Sucker. If anyone has any input on the relative merits of one of these kits over the other I would appreciate your advice. Thanks.

 

You don't *need* to do any tuning work just adding a free flowing air cleaner, however, the bike will run better with some sort of tuner.

btw, neither of those air cleaners are a good choice. They both feed hot, oily, oxygen depleted air into your combustion chambers. This reduces engine performance, and reduced engine longevity.

There are better choices.

Here is a LINK with info on why those type air cleaners are only a half step.


Regarding tuners, here is a thread where the first post is an objective overview of all the popular choices...including why not to waste your $ on a HD download.

https://www.hdforums.com/forum/ignit...uning-etc.html

 

I run big suckers on both my bikes. like dk said, they suck in the blowby from the cylinder vents. doesn't bother me, but a lot of folks have modded them or just went with the no blowby types.



search the net and you'll come up with all sorts of contraptions for catching the oil from the vents. my bikes always have oil on the bottom of the filter. it's not good. especially after an oil change. the engine blows out excess oil. pain in the a**

see here

to be honest, this is happening already on your bike, stock. it's just the way that most a/c's are designed.

 

Some people run breather bolts with screens and no hose. I run breather bolts with a horse shoe and a braided stainless steel hose that runs under my bike. I checked to see the amount of air it is pushing out of the hose with my hand when the bike is at idle and it was massive. The hose is a braided sink connector it cost about $7.00.

 

No, it does not bother a lot of folks, but it does bother the engine.







Besides building up carbon deposits and reducing engine longevity, it also reduces performance.

As Madison Bill noted below, there is quite a bit of air being pushed thru. This air is mostly oxygen depleted air. Mixing this air with gasoline is just a waste of gas...putting that air in is completely counter-productive to producing power and better MPG.

Yes, all factory A/C's do this, not because it is a good design, they do it because it is required by the EPA.

If one is going to spend $ on a aftermarket performance Air Cleaner, it would make sense to not get one that has the performance compromised.


If one really likes the looks of an air cleaner that does not vent externally, then there are EBS kits to convert them to a true Stage I air cleaner. Here is a LINK to some.



Yes, lots of air, oxygen depleted air...and it's hot too, and oily.

Here are a couple of charts showing the bump in power from just venting externally instead of pushing that hot oily air into the engine. What the chart can't show is the increase in MPG when using only clean cool air.

 

i was agreeing with you

 

Got that. Thanks. Just wanted the OP to realize how nasty it is to the engine and performance to push that bad air into the engine.

 

you've got me wondering whats going on inside my cylinders, so i bought a crappy endoscope and will peek in them this weekend.


will see if the seafoam in the gas has made a difference. i remember the carbon covered pistons that came out of me sporty at 5k when i had the conversion done.

 

Not trying to takeover the thread - but what about V-stacks? I have a 2015 - Forty-Eight, and want to go more old school - so either V-stack or Round bell looking cover (thats what I call it) - I want something that looks good but also performs good.

 

imo, you should adjust the fuel with any mods to the pipes or sucker. I put straight shots and a big sucker on my bike- then rode it for a coupla weeks. "Usually" no real problems, although I could tell the bike wasn't running fully efficiently, especially when I really jumped on the accelerator. The bike would often give a slight stall with full throttle. For me it was a safety issue. So I added a Techlusion tuner... and a horseshoe breather. No blow-by and this thing is fast! My tuner has more settings that a carb, and I have set it more for performance than economy (but you have a choice). Never stalls now and it is so fast that I almost never "fully twist the wrist" anymore.
sucker, pipes and breather here: