BMC vs. K&N
03-23-2010 | 08:42 PM
#2
Senior Member
SuperSport
Joined: Jul 2008
Posts: 505
From: Twin Cities
I like my BMC street filter. Quality between the two seem similar but the BMC has the block off plates molded into the underside of the filter just like the stock one.
Last edited by mboe794; 03-24-2010 at 03:35 PM.
03-23-2010 | 09:02 PM
#4
Senior Member
MotoGP
Joined: Apr 2005
Posts: 5,631
From: Montreal
Forum member Tweety did some testing on his personal dyno and found that the K&N did offer the possibility of higher peak numbers but also produced dips at lower speeds. The stock filter works well across the board and comes highly recommended. Finally, he found that the BMC made it possible to boost power slightly across the board once properly jetted for. Do a search and you'll surely find his write-ups (if he doesn't jump into this thread anyhow)
03-23-2010 | 09:04 PM
#5
2nd mouse gets the cheese
SuperBike
Joined: Jan 2008
Posts: 1,697
From: Beaverton, OR
I am running a BMC filter, no flat spots in my jetting, getting 40 to 45mpg on the highway. Took me a little bit to get the jetting right I tuned it for smooth performance and MPG's I could care less about 1 to 2 ponies on top. Stock mains needle 5 and 1/2 notches screws turned 2.75 revolutions. I would recommend the filter as it is also cleanable just like the kandn.
03-24-2010 | 08:24 AM
#8
2nd mouse gets the cheese
SuperBike
Joined: Jan 2008
Posts: 1,697
From: Beaverton, OR
Something to note to for people, I have jetted three supers, and all of them even though they had similar mods had vastly different jetting and responded differently to tweeking. I have no idea why, it would seem they would all be close, like one setting working for everyone, but it doesn't work that way. I am just saying that to suggest why some people have success with aftermarket filters and others don't, at best its a hit and miss deal with one.
03-24-2010 | 02:17 PM
#9
Out of my mind, back in 5
MotoGP
Joined: Nov 2006
Posts: 6,109
From: Skurup, Sweden
Something to note to for people, I have jetted three supers, and all of them even though they had similar mods had vastly different jetting and responded differently to tweeking. I have no idea why, it would seem they would all be close, like one setting working for everyone, but it doesn't work that way. I am just saying that to suggest why some people have success with aftermarket filters and others don't, at best its a hit and miss deal with one.
I tried the K&N in all of them, and every time it made the most top-end, no compromise... But every time it also made the biggest holes... The choice was "Big power - big hole" or "Medium power - medium hole" with that filter, fuel efficiency isn't even close to that equation...
The OEM filter actually makes more power with decent fuel economy than the K&N does when you get rid of the biggest holes, and at that point the K&N still keeps the fuel consumption sky high in compared to the OEM...
The BMC Race filter is apparently the same as the K&N, but I haven't tried it... Both are useful only on a completely built Stage 1/Stage 2 engine with full exhaust and the works, in my opinion... but again, YMMV...
The BMC Street is my personal favorite... In the middle somewhere... Flows more than OEM, but less than the two race filters... Makes decent power with a stock engine with some slip-ons and jetting, without sacrificing fuel efficiency... (And even more than decent with a modified engine like mine...)
Both the Race and Street BMC filters are cleanable like the K&N... Unless you have done serious work on your engine, do yourself a favor and use an OEM filter or a BMC Street...
(Was that what you where waiting for mikstr?...
)
03-24-2010 | 02:32 PM
#10
Senior Member
MotoGP
Joined: Aug 2007
Posts: 2,547
From: Way Out West
03-27-2010 | 07:39 AM
#16
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MotoGP
Joined: Apr 2006
Posts: 4,402
From: Kempner, TX
03-27-2010 | 08:39 AM
#17
Thread Starter
Senior Member
Back Marker
Joined: Aug 2006
Posts: 227
From: IL
That's quite true... I have worked on my own and three others, and had all of them on a bench tuning them... All of those three had basicly just slip-on's added, and was stock apart from that... None of them was the same, none of them ended up with particularly similar jetting, but with very similar results...
I tried the K&N in all of them, and every time it made the most top-end, no compromise... But every time it also made the biggest holes... The choice was "Big power - big hole" or "Medium power - medium hole" with that filter, fuel efficiency isn't even close to that equation...
The OEM filter actually makes more power with decent fuel economy than the K&N does when you get rid of the biggest holes, and at that point the K&N still keeps the fuel consumption sky high in compared to the OEM...
The BMC Race filter is apparently the same as the K&N, but I haven't tried it... Both are useful only on a completely built Stage 1/Stage 2 engine with full exhaust and the works, in my opinion... but again, YMMV...
The BMC Street is my personal favorite... In the middle somewhere... Flows more than OEM, but less than the two race filters... Makes decent power with a stock engine with some slip-ons and jetting, without sacrificing fuel efficiency... (And even more than decent with a modified engine like mine...)
Both the Race and Street BMC filters are cleanable like the K&N... Unless you have done serious work on your engine, do yourself a favor and use an OEM filter or a BMC Street...
(Was that what you where waiting for mikstr?... )
I tried the K&N in all of them, and every time it made the most top-end, no compromise... But every time it also made the biggest holes... The choice was "Big power - big hole" or "Medium power - medium hole" with that filter, fuel efficiency isn't even close to that equation...
The OEM filter actually makes more power with decent fuel economy than the K&N does when you get rid of the biggest holes, and at that point the K&N still keeps the fuel consumption sky high in compared to the OEM...
The BMC Race filter is apparently the same as the K&N, but I haven't tried it... Both are useful only on a completely built Stage 1/Stage 2 engine with full exhaust and the works, in my opinion... but again, YMMV...
The BMC Street is my personal favorite... In the middle somewhere... Flows more than OEM, but less than the two race filters... Makes decent power with a stock engine with some slip-ons and jetting, without sacrificing fuel efficiency... (And even more than decent with a modified engine like mine...)
Both the Race and Street BMC filters are cleanable like the K&N... Unless you have done serious work on your engine, do yourself a favor and use an OEM filter or a BMC Street...
(Was that what you where waiting for mikstr?...
)I've noticed my Hawk screams at the top end. Down low it feels great. But, right at 4000rpms, there is a slight hole. It runs lean there. I have a jet kit, which is installed, and I had to increase the Slow Jet to a #50, and the Needles are in Position 3 from the top, Position 4 from the top is too much gas. The Main Jets are at 178F, 180R.
So, thats what I was curious about.
I can deal with a slight hole in the mid for now, because I ride hard and most of my riding is at higher rpms. But I will probably eventually get a BMC...
03-27-2010 | 09:59 AM
#18
Out of my mind, back in 5
MotoGP
Joined: Nov 2006
Posts: 6,109
From: Skurup, Sweden
Interesting.
I've noticed my Hawk screams at the top end. Down low it feels great. But, right at 4000rpms, there is a slight hole. It runs lean there. I have a jet kit, which is installed, and I had to increase the Slow Jet to a #50, and the Needles are in Position 3 from the top, Position 4 from the top is too much gas. The Main Jets are at 178F, 180R.
So, thats what I was curious about.
I can deal with a slight hole in the mid for now, because I ride hard and most of my riding is at higher rpms. But I will probably eventually get a BMC...
I've noticed my Hawk screams at the top end. Down low it feels great. But, right at 4000rpms, there is a slight hole. It runs lean there. I have a jet kit, which is installed, and I had to increase the Slow Jet to a #50, and the Needles are in Position 3 from the top, Position 4 from the top is too much gas. The Main Jets are at 178F, 180R.
So, thats what I was curious about.
I can deal with a slight hole in the mid for now, because I ride hard and most of my riding is at higher rpms. But I will probably eventually get a BMC...
Then add a pair of those velocity stacks that may or may not work and it gets really fun...
03-27-2010 | 10:08 AM
#19
2nd mouse gets the cheese
SuperBike
Joined: Jan 2008
Posts: 1,697
From: Beaverton, OR
I think what people running the fram filter are doing is they take an oem filter cut the element out then replace it with a similiarly sized fram air filter. I can't tell you if it works real well. Crackerjackman was running it like this but the filter was just laying in there not sealed very well and I have a feeling some of his jetting problems where caused by that, because once everything was buttoned up in the air box his bike ran alot better.
03-27-2010 | 10:32 AM
#20
Thread Starter
Senior Member
Back Marker
Joined: Aug 2006
Posts: 227
From: IL
And that is the infamous K&N hole right there for you... And believe me, you don't know what you are missing since you never had it... Try sticking a OEM filter in there and work on the jetting to get it right, and the midrange of the VTR goes from "fun for a 100hp bike" to "beats the snot out of a 130hp bike" and the top end should stay fairly similar, just goes flat a bit lower in the revs, but the midrange more than makes up for that...
Then add a pair of those velocity stacks that may or may not work and it gets really fun...
Then add a pair of those velocity stacks that may or may not work and it gets really fun...
03-28-2010 | 08:38 PM
#21
Senior Member
Back Marker
Joined: Aug 2007
Posts: 139
From: Mississippi
yup.....just remove the old OEM elements....RTV in a FRAM 3717 (research all done for ya) and I made a cut-out in a piece of tin/sheet metal to sandwich filter to OEM houseing.
This process was posted here years ago under my old user ID.
Fish
This process was posted here years ago under my old user ID.
Fish
03-28-2010 | 10:16 PM
#22
Senior Member
MotoGP
Joined: Sep 2006
Posts: 4,138
From: Austin, Tx
After my last set of mods I had a stumble at 3-4k. Made the bike real hard to ride. I took it back to the mechanic and he apologized for missing the set up. He came over a couple weeks later and installed half-step washers to the needles.
Rocket time! He's twenty years my junior and descibes the bike as "crazy fast" - it is and I mostly never use it.
Yeah, well mostly!
Rocket time! He's twenty years my junior and descibes the bike as "crazy fast" - it is and I mostly never use it.
Yeah, well mostly!
03-29-2010 | 08:54 PM
#23
Thread Starter
Senior Member
Back Marker
Joined: Aug 2006
Posts: 227
From: IL
After my last set of mods I had a stumble at 3-4k. Made the bike real hard to ride. I took it back to the mechanic and he apologized for missing the set up. He came over a couple weeks later and installed half-step washers to the needles.
Rocket time! He's twenty years my junior and descibes the bike as "crazy fast" - it is and I mostly never use it.
Yeah, well mostly!
Rocket time! He's twenty years my junior and descibes the bike as "crazy fast" - it is and I mostly never use it.
Yeah, well mostly!
I am going to ride the SH for the next couple of days to see if it runs richer with warmer temps and more humidity. Otherwise, I'll back the needles off to spot #2, and adjust the Pilot Screws for the air-fuel ratio to see if I can get it right.
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