Boyesen X-Wing?

[macdee]

nice to see some real testing
thanks for sharing mik-str

[fabiostar]

the supermoto/motox world went mad for these type of things a few years ago and it kinda never got proved they helped power. i tried a few on several supermoto bikes and on dynos it never made a difference at all

[mik_str]

well, I found a piece of 0.5mm thick sheet metal and decided it was time to give this thing a go..... So, armed with hand tools, I set about reproducing as closely as possible this particular unit:


To hold it in place, I fashioned little tabs (one per side) into the lower extremity of the blades. I then slid these into 4 small slits that I cut into a piece of aluminum pipe (48mm id, 51mm OD, cut to 7mm) I had bought earlier.

It took a bit of work and final filing to get everything to fit together nice and tight inside the HPower stacks. Once in place and mounted, the horizontal blade ends about 1mm short of the slide.

I went for a ride today to test them out and....... Eureka, it works! The best description I can give is that their effect is in inverse proportion to the amount of throttle opening used to accelerate. I find myself now opening the throttle very little to get the engine accelerating (ie. roll on it slowly as opposed to snapping it open). It pulls very cleanly and strongly from low rpm and lightly open throttle. Their effect is non-discernible once the throttle is open more than halfway.

I had to lean the fuel screws a bit (and richen up the F-C screw slightly) and the idle is now better than before. I was having issues with a hanging idle (had to snap the throttle one or twice when coming to a stop to get the idle down) and that has now disappeared. It's early in the process of discovering how these work but so far, it's quite promising and I am happy with the results......

[NZSpokes]

Dibs for when you go into production.

[lloydie]

Nice write up and good project with a good ending but I. Know it's never the end ha ha not with you

[tony.mon]

Very interesting, Mike.

The whole airflow into the airbox and carbs is something I have been thinking about, too.

The intake snorkel has a dividing blade inside, running vertically.
I thought that it might be for structural rigidity- i.e. keeping the rectangular section from collapsing in the middle- and have removed it from the snorkels I have been working on.
But it also occurs to me is that decreasing swirl and turbulence into the airbox might bring some benefits, and so I had in the future planned to experiment with a better snorkel design, one with lots of small channels but without materially decreasing the cross sectional area.
I considered glued sections of plastic drinking straws together to make a matrix that could be inserted into the snorkel. There is no reason that they all have to be the same length, of course, and so some could be longer, taking air to the rear of the box and making it less likely to disappear down the throat of the front stack.
I think that this is what Honda have tried to do with the blade mounted in the airbox lid.

However I have also been getting a new roof on my conservatory lately, and I used the old triple-wall plastic sheet that came off to put a new roof on the hen house. And that stuff is already glued together in sections...
http://www.roofing-supplies.org.uk/ours ... ength.html
Now that could easily be inserted into the snorkel and secured to the airbox lid. Imagine two sections fitted one on top of the other; the lower one shortened to feed air through the snorkel and to the front stack, the upper one longer to carry air further back to the rear one...

But then-I wonder if more sections to the Boyesen idea might bring even more improvements?

Might be worth a play, don't you think?
(and I like the cheapness and reversibility of using triplewall)

Great work, Mikstr, as ever.

You clearly have more time on your hands than I do

[Ckennedy]

Tony just a wild thought as I don't know much about air boxes but couldn't you ram air the front and rear cylinder seperatly? Feeding each cylinder on its own? Each could have its own smaller air box which could be custom made to help feed the air into each cylinder without have to make a compromise with the other cylinder? If that makes any sense?

[tony.mon]

Tony just a wild thought as I don't know much about air boxes but couldn't you ram air the front and rear cylinder seperatly? Feeding each cylinder on its own? Each could have its own smaller air box which could be custom made to help feed the air into each cylinder without have to make a compromise with the other cylinder? If that makes any sense?

It makes lots of sense.
I think that the only reason that the engine won't run above 6K with the timing 180 out is that the first cylinder to suck in nicks all the air from the box, and leaves the second one gasping- there's no chance to fully replenish back to atmospheric pressure between the two intakes.

So two smaller airboxes ( or a lidless one) would give the option of running a big-bang configuration.

But it would be difficult to seal around the carb joining plates.

I love these little head games

[Ckennedy]

So if you could figure out how to suck the air to the rear cylinder effectively with a separate air box for it then running the bike 180 degrees out would be a very good move? Though thinking about it doesn't ramair only really work above 100mph or so? So you would need a very special air box and intake to get the air to that rear cylinder.

I guess that coffee if had has sent my brain into over drive as this kinda thing I dont normally get involved with, even though I'd like to, but I have to have the objects there to play with so it sinks in.........

More coffee!!

[tony.mon]

So if you could figure out how to suck the air to the rear cylinder effectively with a separate air box for it then running the bike 180 degrees out would be a very good move? Though thinking about it doesn't ramair only really work above 100mph or so? So you would need a very special air box and intake to get the air to that rear cylinder.

I guess that coffee if had has sent my brain into over drive as this kinda thing I dont normally get involved with, even though I'd like to, but I have to have the objects there to play with so it sinks in.........

More coffee!!

I've been thinking about this (and discussing it on here) for years.
Ram air works at all speeds, but only has a noticeable effect (raising atmospheric pressure into the air box) once you get over 70 or so.
But because it will add more air to the fuel/air mix at higher speeds it may well mess up carburation- not a problem with fuel injected engines, but with carbs you will have to compromise somewhere, probably running rich at tickover and on the pilots.Not a major problem, as these lumps like rich.

I'm not saying that a big bang configuration engine would develop better power, torque or driveability, but as you can see from racing and the R1, for example, it's on option.

And it sounds much better on the exhaust note

[VTRDark]

I wonder if this has a similar affect to what the so called restrictor plate which Honda puts in the intake tract on later models. IMO I think that was put in by Honda to give more flow velocity at lower revs rather than have the mix stall in the port (possible addition to carb coughs and stalls). More of an issue at low speeds and bigger carbs!! And something that will work very well to help low speed smoothness/rideability, especially with an engine which has been tuned to give a bit more top end/where the power curve has moved up the revs. The only difference I can see with this device is that rather than sit in the intake tract and deal with the complete mix of fuel and air, this works on the air side only.

Tony I'm not sure if less turbulence is a good thing. I was reading somewhere that more turbulent air is required to help with atomisation of the mix. With more turbulent air, the particles are broken up more as they mix with the fuel giving a more even mix/consistency. A similar device is a metal gauze like you get on some open airbox trumpets/V stacks. And didn't some bikes have a metal gauze on the inlet tract side to help break the fuel particles up along with the air, keeping them more in suspension.

Maybe instead of less turbulence being required a more controlled turbulence is required, which is what the dividers in the snorkal and airbox may be about. Also isn't the Flow Commander for something along them lines. Mmmm.... maybe I'm on too much Coffee too

The way I see it, there are two things were dealing with here. Velocity and turbulence. Now ho's one work out the max velocity required and........well, if only we had a transparent airbox and some form of dry ice or dye so we could visually see the turbulence and airflow.

All very interesting stuff Mik. Keep us updated on how things go.

(:-})

[sirch345]

Great work Micky very interesting to read this thread

Chris.

[mik_str]

Just got in from another ride (about 140 km, or 85 miles) and I am liking this X-wing device more and more. It has beefed up the low-end and mids in a significant way; just a gentle roll-on of the throttle (granted, I have an HRC 1/6 turn tube) and the bike vaults ahead. I also noticed it has smoothed out the engine at cruising speed (@4500 rpm) too.

No downsides so far......

BTW, I will be taking them out likely later this week to do some final finishing touches (seeing as how they'll be staying in) and will snap some pics then......

[sirch345]

Look forward to seeing your hard work from the photo's Micky

Chris.

[mik_str]

Nice write up and good project with a good ending but I. Know it's never the end ha ha not with you

lol, funny you should mention that.... just thought of something.... more to follow....