Paper Filters & Airbox Lid Mod

[Greg Field]

The lasting power of the K&N myth ("filters even better when dirty!") suggests that nothing will ever be enough to convince those who do not want to be convinced.

[DeBenGuzzi]

The lasting power of the K&N myth ("filters even better when dirty!") suggests that nothing will ever be enough to convince those who do not want to be convinced.

both sides can sazy such things but it seems as long as the rocks stay out of there and you change the oil regularly I haven't seen anywhere that it really matters, stock filters are great but I like me looks, thats all that matters.,

[Greg Field]

both sides can sazy such things but it seems as long as the rocks stay out of there and you change the oil regularly I haven't seen anywhere that it really matters, stock filters are great but I like me looks, thats all that matters.,

 

Buy a Harley. Stylistically, the V11 is a MESS.

[guzzi323]

I've had a K&N in my BMW for 150,000 miles or so. When I pulled the heads off at 100K the cylinders still had their honing marks. I put some fresh rings and rebuilt the heads and the bike still runs great (for a BMW) and is as reliable as dirt. When I got the Scura the idea was that it was going to replace my tired old BMW. I love the Scura, but even after 24 years my BMW is more reliable even with the K&N filter.

 

My

 

johnk

[dlaing]

Ok Greg (and everyone else), I'm going to throw out a couple if questions and observations: Is it possible that the bone stock set-up with the snorkels is acually faster in the real world? It seems to me that stock there is a ram air effect that, at speed would tend to force cool air into the box, if I'm wrong here, why? Forget the dyno babble, last time I checked, Dyno's have not been spotted circulating the racetrack Has anyone ever done a TRACK TEST and/or 1/4 mile comparison between the stock airbox, a cut-up box, and individual K&N pods ?back to back, one after the other against the stopwatch? And on that subject for a moment, is there any difference between K&N filters and the BMC's? Back to the Air box issue, what about the crankcase venting sustem? Doesn't the vacum of the stock box help draw out some of the pressure? When you cut up the box, and/or install indivudal pods, don't you loose some of that? As a personal note, I have used K&N filters for many years on various race cars. But that has nothing to do with engines that you want to run for 10's of thousands of miles without having to tear appart! I have never used them on a street engine that I ever lived with long enough to see any effects either positive or negative.

Excellent questions and ideas!

It is certainly POSSIBLE that in the real world the bone stock setup is faster.

But theoretically, I doubt it has advantages towards faster accelleration.

The angle and size of the snorkles is designed to minimize sound and keep debris and rain out, while not strangling the engine, too much.

It does appear to give a very small increase in positive pressure, and more importantly it picks up the air from a cooler place. ...but not enough to give a wallop of power

If they wanted real world benefits of ram air, they would have to funnel the air into the airbox starting with a much bigger mouth, and it would have to face forward, but still provide deflection and drainage of water and debris.

FWIW, I really like GuzziJack's approach

Tracy Martin's sewer pipe is not a bad idea, either.

Regarding crankcase venting air pressure, I'll bet the engine can develop more power and make less milkshake if there is less crankcase air pressure.

I know my filter housing could never pass a white glove test, regardless of filter, because my crankcase vents so much oil.

However, compared to Greg's dry clean machine, my oil warning light does not go off even though I run my oil at a much lower level than he does. It does not make sense to me.

[Greg Field]

Dave:

 

These're funky EYE-talian machines. Every one is mercurial and quirky in a different way. Mine's got 12,000 miles but blows no oil. If I accelerate to its ability to do so, the oil pressure plummets to zero. I do not pretend to understand it, but I won't ignore it, either. I got a Roper sloppage plate on Friday. With luck, I'll be able to install it this week, and then I'll be able to drag-race to my heart's content.

[Phil A]

Greg,

can see there is a few here interested in this so I dug out some data gathered while developing the V10 inlets. Dont shoot me please the box is the same as the V11

 

The facts as I have them are these:

All of these steps are independent of each other.

 

If your remove the origional mufflers(snorkels) off the inlet and bell mouth the inlets to approx 35mm id you get approx 2hp between 4500 and8000rpm.

 

If you remove the filter but leave the lid in place, you get approx 1.7hp.

 

If you drill 3 one inch holes in the top rear of the air box lid (one in each corner an one 2'' forward in the center) and retain the air cleaner element you get approx 1.5 hp.

 

If you remove the lid and leave the filter in place you get approx 3.5hp from 4300-5500rpm it increases steadily to approx 7hp at 6300 then tapers of to approx2 at 8000 or so.

 

Once you totally remove the air box but retain the std bell mouths on the injector bodies the gains above 6300 do not taper off as above with the gain being approx 5hp at 8000 or so.

 

Probably the most noticeable gain with this last set up is 4 or 5hp in the middle of the dip at 4000- 4800rpm.

 

If you increase the bell-mouth id to approx 50mm and retain the holes in the rear you get 4.5hp all up.

 

Once I had remapped the MY16M to match I have exactly the same power with the airbox (with origional filter) as with no airbox what so ever!

 

A total gain of approx 7hp while running the stock filter.

Probably the best gain was 9ft/lb at 2700rpm! with a 5ft/lb gain at 4300rpm.

 

Hope this is of interest.

 

Phil A.

 

V10 sport.

 

 

 

"All is not always as it seems"

[dlaing]

 

Once I had remapped the MY16M to match I have exactly the same power with the airbox (with origional filter) as with no airbox what so ever!

 

A total gain of approx 7hp while running the stock filter.

Probably the best gain was 9ft/lb at 2700rpm! with a 5ft/lb gain at 4300rpm.

 

Hope this is of interest.

Definitely of interest!

I wonder what the gains would be if you remapped for all the various changes

Presumably no airbox would create the leanest running condition, and therefore would benefit the most from tuning.

However, experiences shared on this forum indicate the most power coming from PCIII custom mapped bikes with the lidless airbox and not the K&N Pods.

[ArtD]

Greg,

can see there is a few here interested in this so I dug out some data gathered while developing the V10 inlets. Dont shoot me please the box is the same as the V11

 

The facts as I have them are these:

All of these steps are independent of each other.

 

If your remove the origional mufflers(snorkels) off the inlet and bell mouth the inlets to approx 35mm id you get approx 2hp between 4500 and8000rpm.

 

If you remove the filter but leave the lid in place, you get approx 1.7hp.

 

If you drill 3 one inch holes in the top rear of the air box lid (one in each corner an one 2'' forward in the center) and retain the air cleaner element you get approx 1.5 hp.

 

If you remove the lid and leave the filter in place you get approx 3.5hp from 4300-5500rpm it increases steadily to approx 7hp at 6300 then tapers of to approx2 at 8000 or so.

 

Once you totally remove the air box but retain the std bell mouths on the injector bodies the gains above 6300 do not taper off as above with the gain being approx 5hp at 8000 or so.

 

Probably the most noticeable gain with this last set up is 4 or 5hp in the middle of the dip at 4000- 4800rpm.

 

If you increase the bell-mouth id to approx 50mm and retain the holes in the rear you get 4.5hp all up.

 

Once I had remapped the MY16M to match I have exactly the same power with the airbox (with origional filter) as with no airbox what so ever!

 

A total gain of approx 7hp while running the stock filter.

Probably the best gain was 9ft/lb at 2700rpm! with a 5ft/lb gain at 4300rpm.

 

Hope this is of interest.

 

Phil A.

 

V10 sport.

"All is not always as it seems"

 

 

This is all VERY interesting! Were any of these tests then followed up by any track testing with a stock baseline to campare the midifications to? sometimes things do not show up on a dyno, but smooth out and/or alter the power curve and thus you can go faster where it counts. Am I right that what might acually work the best then would be K&N pods? Would that aproximate removing the airbox yet retaining the rubber bellmouths on the injectors? And then increasing the bellmouth to 50mm and drilling the three holes at the rear to balance the box out seems to be annother viable alternative.It seems then that there is a little ram air effect with the stock air box but not much. When you look at the amount of hp that the Jap bikes create with their state of the art boxes, it seems that there is a bunch of hp waiting there

The minor problem is digging it out

[docc]

Could the 'dirt gathering comparison' be more a function of the pods facing rearward and the airbox openings facing forward?

 

It just seems that you'd get fewer bugs in your mouth with it open facing back.

[Guest Nogbad]

I know this may sound a stupid question, but if power pops your "pod" (no pun intended) why are you struggling with an old 2 valve ditchpump.

 

Why not buy a state of the art Japanese crotch rocket?

 

1.7hp? 5hp? These gains will be unnoticeable beside the effects of a heavy lunch or not taking a dump before your ride. Let alone air temperature and humidity.

 

Forgive my impertinence, but these airbox and filter issues seem to me to be just so much bunkum.

[Greg Field]

Greg,

can see there is a few here interested in this so I dug out some data gathered while developing the V10 inlets. Dont shoot me please the box is the same as the V11

 

Nobody gets shot after they do the work and share the results. Thanks for this. It will save me some work.

 

If your remove the origional mufflers(snorkels) off the inlet and bell mouth the inlets to approx 35mm id you get approx 2hp between 4500 and8000rpm.

 

I never would have guessed this would do much. That's what guessing gets you, though.

 

 

If you remove the filter but leave the lid in place, you get approx 1.7hp.

 

I would have guessed this would help more.

 

 

If you drill 3 one inch holes in the top rear of the air box lid (one in each corner an one 2'' forward in the center) and retain the air cleaner element you get approx 1.5 hp.

 

This is sorta what I have done. Except instead of holes, I cut out a 4x4 square out of the top of the airbox. I guessing this will closely approximate taking the lid off entirely, but it's a guess. I'm not after every single horsepower—just what I can get without compromising the air filtration system and without getting that "giant sucking sound" from pods or a lidless box.

 

 

If you increase the bell-mouth id to approx 50mm and retain the holes in the rear you get 4.5hp all up.

 

Does this mean with the airbox in place, with the holes drilled in it and the intake snorkels opened up, but with the bellmouths on the throttle bodies opened up to 50mm?

 

 

Once I had remapped the MY16M to match I have exactly the same power with the airbox (with origional filter) as with no airbox what so ever!

 

A total gain of approx 7hp while running the stock filter.

Probably the best gain was 9ft/lb at 2700rpm! with a 5ft/lb gain at 4300rpm.

 

Hope this is of interest.

 

Exactly what I'm after. Definitely of interest and thanks!

 

GF

[Guest ratchethack]

"All is not always as it seems"

Phil, I appreciate your careful work and analysis. This is indeed of value and interest.

 

When comparing breathing characteristics between V10 and V11 motors, what you said above may bear repeating.

 

It may be important to others to point out that while the V10 and V11 share the same airbox, it should not be overlooked that the hi-cam, 4-valve heads and pistons - and therefore combustion chambers as well - have only one basic element in common -- bore and stroke of the cylinders. In fact, other than this, they could hardly be much more different from each other. So I would expect entirely different flow characteristics and intake tract harmonics, resonance, etc. through the same air box. Overall, the 4-valver would of course have more significant flow efficiencies over the 2-valver, particularly at higher RPMs.

 

Just emphasizing that your findings may not translate even in the same ballbark, so to speak, to the 2-valve motor. It could reasonably be expected that the numbers you cited would more'n likely be lower overall with the 2-valve heads. As far as I'm concerned, though certainly of value and interest, WRT the V11, this exercise is for the most part academic. As mentioned before, I'm personally not concerned with chasing smallish variances in output at WOT and peaks on charts, but nevertheless I'd very much like to see the same work and analysis applied to the V11.

[dlaing]

I know this may sound a stupid question, but if power pops your "pod" (no pun intended) why are you struggling with an old 2 valve ditchpump.

 

Why not buy a state of the art Japanese crotch rocket?

 

1.7hp? 5hp? These gains will be unnoticeable beside the effects of a heavy lunch or not taking a dump before your ride. Let alone air temperature and humidity.

 

Forgive my impertinence, but these airbox and filter issues seem to me to be just so much bunkum.

I am sure Erik Buell spent many sleepless nights contemplating different ways to grab just one more HP.

If add a few HP here and few HP there, and loose a few ounces here and a few ounces there, you get a lean mean screaming machine.

Of course there is nothing wrong with lowering your compression to reduce pinging, putting socks over the snorkles to pre-filter out more dirt, adding cromed steel spoked wheels, steel fenders, brass bearing spacers, reduce your timing....before you know it, you'll have a nice heavy slow bike. ..or you could just by a Ural But some of us chose to go the other direction.

[badmotogoozer]

That's the nice thing about K&N's - you never need to vacuum the crap out of them.

 

Rj