Bonneville America Forums Forums Technical Forums Performance Mods Uni vs K&N vs. ?

I'm new to motorcycling, just got my license this summer and bought my first bike,so I'm starting slow with trying to improve my bikes performance. I've been reading as much info on this site as possible and have decided to start making changes. I just yanked out the snorkel, what a worthless piece of junk that thing is. I'm sure removing that alone makes a big difference in air flow. I am going to put a bellmouth in the opening, and I may cut out the bottom of the air box as well. Obviously I need to replace the stock paper air filter, and that is where my question lies. Is there any difference in performance between the Uni or K&N? Is one better with bottom of the airbox gone than the other? Is there another filter that I am unaware of? Thank you in advance.

If the K&N is gauze similar to the pods (not sure on this) it is cleanable and will flow well but won't filter as well as the Uni foam. The foam Uni is also cleanable but won't flow quite as well as the K&N. I run the K&N pods myself.

Jason,
FWIW, I'd suggest you go with the Unifilter for now, before you start cutting up your airbox. It's a simple enough mod (and not too expensive), along with the Polaris bellmouth, that will help your engine breathe better. Ride it like that for a year or three, before you start doing major changes like removing the airbox, installing pods, etc.

Steve

Personally I'd start with some subtle changes until you are comfortable riding the bike. +1 on the cheap upgrade air filter. then I'd get a set of mix screws from brent to replace the "D" screws if you have them and delete the AI. All pretty simple tasks and the members here are great for advice or walkthrough tips.

Then save up for a year or two and then pick up a set of pipes and go for the air box delete and battery relocation. Then if you really want to change things up you can bob the fender for a custom look... and on from there.

Welcome to the site and I hope this helps. NR

Hello Jason,

Welcome to the site. Both filters are good quality. The Uni is considerably cheaper. You need to purchase the oil with the filter for the initial soaking.

I agree with what the others stated. Start simple. Make 1 change at a time. Make sure you keep up with the carb jetting as you increase the air flow into/out of the engine. Removing the snorkels (there are 3 on the early Americas) required that I up my mains and shim my needles. If you cut the bottom of the airbox, you might have to increase size again but run the small risk of getting water into the airbox during heavy rain riding. If you do open up the bottom of the box, it is reversible.

I was speaking to the single OEM replacement and as stated I wasn't even sure of that since I went straight to the pods.

I can't reasonably foresee why a single stage Uni of any configuation wouldn't be capable of outflowing a K&N, all other things equal.

I currently run K&N pods on my SM, although I have run Uni's of different configurations on other bikes.

I will probably go to black foam single stage Uni pods on the SM at some point, too.

Thanks for the input guys.

I am also planning on debaffling my stock pipes as well, trying to decide on how many to remove at this point.
And removing the AI seems like a worthwhile, cheap and easy job as well.

Is it recomended that I remove the 2 snorkels located inside the airbox as well?

Both UNI and K&N will be noticeably better than stock. I doubt anyone can tell the difference between the two. I like the UNI as it is very easy to clean and re-oil. I only lightly oil but feel the oil helps in retaining small dust particles.

I'd try it with the new filter, bellmouth, and snorkel removed before cutting the bottom out. You may find that unnecessary. You may also need to change your main jet with the increased airflow.

The two snorkels on the inside were only on 04 or earlier models. Yes, remove them as well. They were taken off of all factory models by 2005.

Guys I wasn't speaking of a noticeable difference and have no data saying one flows better than the other. I just figured that oiled foam would flow less air than a gauze filter but not to the point of needing any re-jetting or anything. I also could be wrong about that as I originally stated.Personally for a stock air box I would probably choose the oiled foam but like the K&N for the pod application, again just my personal preference.

ok, so all three of the snorkels have been yanked out, there remains a flimsy piece of plastic between where the two inner snorkels were. Should I cut this out, or leave it as is?

Leave it as is and just remove the snorkels. The remaining plastic will make no difference.

Awright, folks, since we're talking about K&N pods -- I know the two "usual" pods to use for the Speedys etc are the K&N 2890 and 2900. Anybody try any other K&N pods, preferably with a flange angle to get the pod away from the nubbie things on the frame?

Also, what's the deal with the DNA pods, and can we get them here in the States (without it costing an arm and a leg)...

--Jaeger

I personally can't really say much about the flow differences between uni and k&n. I do know that in the shop we see ALOT more bikes and atv's with the top ends worn out due to dust getting past k&n filters. Personally I think it's due to improper installation(not greasing the mating surface)and improper oiling. Granted this is a more serious issue with offroad bikes which comprise the bulk of our work. I personally prefer UNI over K&N, due to the ease of cleaning.
Another good idea is to armorall the interior of the air box, the armorall atracts dust and keeps the filter clean significantly longer as well as making the box easier to clean. I also agree with making mods a step at a time and avoiding cutting the bottom out of the airbox,When you get caught in the rain you'll end up with a water soaked filter and a bike that wont run. I'm sure I'm not the only person here that experienced the joys of sitting beside the road in the rain atop a non functional bike.

Thanks for the input
I think I'm going to leave the airbox as is, the last thing I need is sitting on a roadside in the rain, and I should see plenty of benefit from a higher flow filter.

Put in the UNI, and add a bellmouth. I guarantee you a noticable difference in airflow without modifying the box.