Hey guy's just wondering,

K&N RK 3909  or the RK 3910 ?

 from what i can tell they will both fit the 2011 Softail deluxe ,

The 3910 seems to flow better( thicker filter) = up to 12 Hp gain

The 3909 is slightly thinner less flow (thinner Filter)= up to 7hp gain

The Bike is running stage 1 filter upgrade, V&H bigshots , SEPST , at the moment

So guess that is pretty much regarded as close to  stock,

Any comments or recommendations on which way to go,

Does anyone use either one of these

Appreciate any feedback

Cheers TB1

Stick with the stage 1. Ran the K&N kit on my '07 deluxe for less than 12 months. Was recommended by dealer when I bought the bike new. Disappointed with the design, as the vents dripped oil inside the filter & the rubber air stack kept falling out of it's mounting position. Poor design from a well known company.
 
Replaced it with the SE stage 1 kit & put in the Zippers Maxflow filter element which is about 1/4" or so taller (PN 1011-0782). A company called Exotx makes a stainless element that should work also.
 

Hey KiwiRob,

Thanks for the input man, will heed your advice,

I was hoping to hear from somebody who has either used one or is using one.

cheers mate

Will definately look into your recommendation on filter element

TB1

 I fitted the Dyna equivalent model (RK-3931) on my Fatbob.

Had a heap of trouble with bolts shearing off the stand offs thru vibration.

If I had my time again.........I would have just bought the K&N filter to fit the standard backing plate. (at the time, I wasn't aware that K&N made a filter to suit)

The K&N filters themselves are the ducks guts, however the rest of the hardware is not as reliable as the standard or SE set up!

Burto.

Hey Guy's ,

Thanks a heap for the info, saved me some bucks,.....Ta

will just upgrade the element  instead,

Cheers

TB1

Should have said there's nothing wrong with the K&N filter elements, sorry to say their backing plate & air stack is a disappointment.