Airbox modding

[lloydie]

No it's as long as it can be .
The frame is in the way

i know it goes into the headstock area, but when that area is plugged by the snorkel where is it drawing air from?

from under the air box .
theirs a tray under the carbs to stabilize the air flow from the front of the bike .
if you remove it it will run like crap so that cant be removed .
you can mod the snorkel like tony and i have (making it bigger )so you can get more air in .

[VTRDark]

when that area is plugged by the snorkel where is it drawing air from?

The snorkel is not plugged as there is a small gap between it and the cowl just like the gap between the V stacks and air filter. I have a theory and think the front vents (the non ram air vents as it's not sealed) come into play here. A certain amount of air flows down there and I think it flows between the carbs and into the plastic cowl and up around the airbox then into the snorkel. The cowl must help stabilise the air or maybe have a venturi effect that helps force the air up and around the airbox.

What I find mysterious is under the snorkel on the plastic cowl there is a sealed blank the same size as the end of the snorkel inlet. What is that all about unless the same cowl is used on another bike where it's not needed.

It's a shame we can't magically colour the air particles so we can see the exact flow of things.

(:-})

[seb421]

when that area is plugged by the snorkel where is it drawing air from?

The snorkel is not plugged as there is a small gap between it and the cowl just like the gap between the V stacks and air filter. I have a theory and think the front vents (the non ram air vents as it's not sealed) come into play here. A certain amount of air flows down there and I think it flows between the carbs and into the plastic cowl and up around the airbox then into the snorkel. The cowl must help stabilise the air or maybe have a venturi effect that helps force the air up and around the airbox.

What I find mysterious is under the snorkel on the plastic cowl there is a sealed blank the same size as the end of the snorkel inlet. What is that all about unless the same cowl is used on another bike where it's not needed.

It's a shame we can't magically colour the air particles so we can see the exact flow of things.

(:-})

For a cheap Red Neck style wind tunnel you could stick a Storm on a treadmill in the garage and have a large fan and Benny (he does get through a pack at a rate of knots) stood behind it chain smoking and see where his passive smoke gets drawn into the bike's lung

[tony.mon]

I see where you're going with the plastic undertray; that one had occurred to me as well.
If you cut out that blanking plate rectangle it would be possible to fit another snorkel aimed forwards and bending up under the tray to fit into the std one, giving ram air.
Sadly, the bracing bar (the round one that goes sideways behind the headstock) doesn't allow this.

But there is another route....

Supposing you blanked off the plastic heatshield, sealing it so that it effectively became a sealed pre-intake box.

Then you could feed air into it via those triangular gaps in the frame; the left hand side is left empty once you've removed the front coil after a stick coil mod, and the right hand one only has the throttle cables going through.

It wouldn't take too much work to re-route those to go in form underneath, leaving the two triangular gaps for some sort of ram-air routed form the holes in the front of the fairing.

[VTRDark]

It certainly gets the old brain ticking these airboxs and how the VTR takes on it's air supply. It's also surprisingly fragile and mysterious. I don't think those front vents are there just for aesthetics. they must feed air down towards the base of the airbox at higher speeds. Just not that efficiently because of the leaks in the design of the plastics and how they fit. But then there is also the air that generally surrounds the box from the sides of the frame which I suspect the bike utilises at lower speeds. I wonder how those Durbhan rad airfoil things and reversing the fans affects things. That surly would send more air in towards the airbox.

The thing is Ramair is only any good at high speeds/track and not much use on the street. So looking at Yeti's pics and how it's all enclosed with the carbs and the enclosure acting as one big airbox and the only air entering is basically the Ramair tubes. What we need is some kind of hybrid. So how about enclosing those tubes more so they are more of a sealed unit that leads to the airbox plastic cowl. But not closing off the cowl completely as we still need the airflow at lower speeds.

I may be barking up the wrong tree here and just waffling, but my head is brainstorming.

(:-})

[tony.mon]

Sorry, Carl, I led you astray there, the intakes in the front are purely to allow an airstream to blow across/through the side mounted rads; they're nothing to do with ram air, or any air into the carbs/airbox.

But I think that there's enough air flowing over the rads anyway, unless it's exceptionally hot, and in that case I already have a larger oil cooler fitted.
If overheating occurs I'd simply fit a second rad fan, sensor and over-ride switch; in fact I've already bought some of the parts for this conversion, just not got the slimline fan yet.

So that frees up those intakes, and what better use than to feed into the cabs somehow?

[mik_str]

Thread revival!!!!!

Regarding the platic shelf found under the airbox and snorkel... do NOT modify it (ie. cut hole in base). Been there, done that.... bikes surges at highway speed in the presence of crosswinds. What I have done is trimmed it back along the sides (where it meets the frame spars), making it easier for air to enter the "pocket" where the snorkel draws air.

With my bike running great again.... it's time to mess it up, lol I just took my modded airbox (verysimilar to Lloydie's) out of storage and am thinking of giving it another go. I have some small cone filters for the carb slide vents. As for the valve cover vents, I decided to install some 90-degree elbows (where the entance points are on the stock airbox) in the bottom of the box and will run them into the box, feeding them into the Krankvent valve (one-way valve designed to apply a slight vaccum to the sump to reduce pumping losses; http://www.et-performance.com/kv.html#M ... &_CRUISERS).

My question is this: what jetting changes have had to be made after swapping from a stock box to the modded (larger voume) version. Keep in mind that I have a Flo-Commander that will allow me to play with the main jet circuit witout pulling the carbs apart......

thanks in advance!

P.S. I have the exhaust supports for my high-rise pipes off getting powdercoated at the moment. I will re-try the high-mounts once I get them back. The link pipes for the hi-mount pipes seem to be 3-4" longer, which, in theory, should give the lows and mids a slight boost (furhter helping the gains from the airbox)...... Of course, the carbon frame covers will get me another 5 or so hp anyhow..... lol

[lloydie]

I have all stock parts fitted at the moment
I am going to refit the gutted air box on the dyno day so sadly I can't advise till then .
On my old set up (2-1) with the gutted box it was hard to tune for 0-3.5k cruse and getting throttle responses crisp too was a challenge .

[mik_str]

cheers

[mik_str]

gave my airbox another roun of expansion mods as I kicekd out the two back corrners, so they are now square. The gains re not masive, but every little bit helps......

[lloydie]

What no pics :-( you should know better by now :-)

[mik_str]

things happen more slowly out here in the colonies, lol

will get pick up shortly

[8541Hawk]

It will be interesting to see how it works out.
I'm still doing research on how much it needs to be enlarged but am finding very little info so it might just be trial and error to figure out.

Which also means I won't be doing a whole lot with it right now as why do it now, then build an engine and need to do it all over again....

[mik_str]

oh, someone's building an engine........

[8541Hawk]

oh, someone's building an engine........

Well slowly gathering parts and still working on the guy that has the mori cams.....so one of these days........