That information was available for the Rushmore air filters. Just checking to see if anyone has tested a stock air filter for the M8. One of the points HD made about the M8 was it had a "high flow air filter"

 

I know it flows plenty for the Stage 1 Street Tuner calibration and Street Canons. I left the stock air cleaner alone and it runs fantastic. Pulls strong and smooth all the way to Redline. I think it's fine until you go to Stage II and up. All those SE air kits are designed for their performance upgrades thru Stage 4. If you think about it, when they redesigned the new motor and increased overall air flow they didn't neglect the intake and design it to be exactly just enough for the stock calibration with a brand new filter.

 

Thanks for the input. That makes sense. Since HD went with synthetic media filters the stock ones flow a lot better than they used to.

 

the stock filters are still paper, and smaller than the synthetic media kit upgrades..but they are washable..for $20 apiece I bought several and just make sure to rotate them before they get too dirty..I like the better filtration overall weather protection for touring, and think the design of the air box itself lends to getting enough air past the filter into the throttle body..just my opinion based on early impressions..I see no need to upgrade my intake

 

I haven't bothered to put the M8 OEM filter on the flowbench, however the element is tiny and the media section is only just over an inch thick. On average we see a solid 2-3 Hp in Stage 1 applications with the various M8 prototype & pre-production air cleaners we have tested for several manufacturers.

Here are some images of the stock element

 

well if you believe the DYNO chart Harley provides for their Stage 1 with Street Canons, Heavy Breather and Stage 1 calibration, and don't know why we shouldn't because the published gains are so nominal, bordering on anemic for cost/value .... couple hp throughout and 5 tq at 3500 (small but at least in the right spot)..and with the street canons and S1 recalibration w/stock intake the gap is even smaller...way I see it I might gain 1 hp and couple TQ if I upgraded my stock airbox to a $400 SE HB.

So my perception is a $400 upgrade gets me an almost imperceptible performance gain, that is noisier, has to be serviced/oiled, passes more airborne contaminants and have to screw around with a rain sock.

http://www.boardtrackerharleyonline....ed/2017_SE.pdf

 

Thats the way I am looking at it as well. And something you might find interesting. The founder of a Harley exhaust system company told me an interesting story. They were dyno testing an exhaust system and the numbers were lower than they expected. So they removed a K&N filter from an SE air cleaner and cleaned and oiled it. Put it back on and lost 3 hp. So they removed it again and cleaned but did not oil it. Regained the lost hp plus a couple. They experimented with oiling and his conclusion was this. Over oil it by just a little and you lose power. Under oil it by just a little and it lets too much dirt in. He said there was no way the average person could get the oil just right on one of those filters. That made me rethink the whole K&N thing.

 

I put the ventilator filter on bigger than stock cost 289.00 no sucking noise and I have run similar open filter a/c on all my bikes in rain that was hard enough that each breath was a drink of water no problems I don't even cover them at nite when it rains in 10 yrs and 10's thousand of mile using them never an issue. I did hear the SE HB has a whistle to it. Just my 2 cents

 

good feedback/conversation..I just think at the end of the day it comes down to..Stage II and above absolutely necessary to upgrade A/C (obviously)..Stage 1, not so much..especially on touring bikes where the overall protection and quietness the OEM unit provides is more important than a couple of ponies

 

Jamie can elaborate more on this but I'm thinking I saw somewhere that the Breather is very restrictive, as much as 10hp and tq gain by removing it, if that's true then only the best will do when trying to squeeze every ounce of flow to the engine.