Introducing the "Race Duct" XC Intake

Duster · #1 (**permalink**) 08-30-2010, 04:58 AM

Well I let these sketch-overs out of the bag in another thread... so I figured I'd give this thing it's own thread for discussion...

This is strictly an XC racing box... because hauling ballz is required for the theory to work... The sketch-over pics are pretty self explainatory... and there is a little bit more to it than that, but the basic setup nonetheless...

Can be ran with the relief valve lid or with no lid at all... with outerwear of course...
But the whole layout REQUIRES that you be hauling arse...
So that anything that gets in comes right back out...
Rather it comes in the top cause you didn't run the lid...
Or because you sunk deep enough to submerge the duct...

And if you submerge it with the lid on the relief valve opens easier than water can be sucked up into the filter...
And if you sink her and stall out, of course the valve doesn't open and air pressure is trapped in the box above the water.

Yeah, if you swamp it good and deep it's over.... but you're not supposed to do that right?
You're supposed to be picking the good line and trying to win the race...

Anyways, just thought I'd give this one it's own thread and see what people think about it.

As I am messing with the other versions, I'm tinkering along with filters and oils and materials and outerwear type materials and internal shielding ideas, etc... When I feel everything about it is right, I'll take it out and bust some creeks and mudholes wideazz open to put it to the test...

kfx450r#490 · #2 (**permalink**) 08-30-2010, 09:43 AM

go for it duster! hey if you want a test rider to try it in mud and water im open to it!

AZkfx450rider · #3 (**permalink**) 08-30-2010, 12:14 PM

dude there has to be a box out there, havnt u seen those videos on you tube of ppl riding in like 4 feet of water? granted some of those are the big utility quads but probably some 450s as well

Duster · #4 (**permalink**) 08-30-2010, 12:50 PM

Quote: Originally Posted by AZkfx450rider

dude there has to be a box out there, havnt u seen those videos on you tube of ppl riding in like 4 feet of water? granted some of those are the big utility quads but probably some 450s as well

Yeah, they snorkel them up with PVC or ABS...
But it's rather pointless on the KFX unless you stack the exhaust too...
I don't really worry about that because I don't do the deep crossings.
Exhaust depth is plenty for me... (although this setup is well below that)

Duster · #5 (**permalink**) 08-30-2010, 01:07 PM

Quote: Originally Posted by kfx450r#490

go for it duster! hey if you want a test rider to try it in mud and water im open to it!

OK... I'll keep it in mind because I'll surely need some if there is enough interest to get this one off the ground.

There is a bit more safety to it than meets the eye here in the details.
But people are going to want to know folks tried it.

I'm not made of money, so I will have to feel super comfortable to test it myself.
But you know folks are going to want to hear from "others"...

The funny part to me is that this is one of the first layouts I did, and now after some testing of more conventional layouts, I'm returning to work on this one and adding detail features... because I have found that in most hard riding applications it is believe it or not a lot easier to get stuff on the filter of the conventional box & no lid. The only battle to fight is making it as safe as possible for the one time you or someone in front of you makes a mistake... like getting sunk too deep or getting stopped in water. Gotta build it and take it with some test equipment down to the river for a dunk...

nkeen07 · #6 (**permalink**) 08-30-2010, 08:20 PM

I think it's awesome that you're wanting to try other ideas. I'm worried about the open back though. That's one place of my box that gets covered fast in a race. Stuff will find its way in w/that design a lot faster than w/an open lid. How about having an opening in the top of the back of the box above the line of the plastic instead and putting a one way drain valve on the bottom?

Duster · #7 (**permalink**) 08-30-2010, 09:27 PM

Quote: Originally Posted by nkeen07

I think it's awesome that you're wanting to try other ideas. I'm worried about the open back though. That's one place of my box that gets covered fast in a race. Stuff will find its way in w/that design a lot faster than w/an open lid. How about having an opening in the top of the back of the box above the line of the plastic instead and putting a one way drain valve on the bottom?

I'm finding the opposite... I find it effortless to get stuff inside the box with no lid... But I have came up with a solution to that, so you will see that coming in the next version. It will have a LARGE one way drain valve, maybe a few if I can find them... as a last resort if something should get in.

What I am trying to figure out to finalize this duct box though is how far I can really come back without contact on a bottom-out. I guess I can strap it down... but I can't account for aftermarket linkages.

I figure I have 2 options... just do it for stock linkage and travel... or shorten it forward some.

I made 2 additional options for the closed lid version today too...

Option one is that I put a flange in around the inside on the bottom under the filter.
It's going to have a full outerwear type lid under there.
The typical box... upside-down basically... with a duct.
(I could turn the same layout over as well)

Option 2 is that I could leave the box shape just like I have my first blank and outwear the duct...
Doing so though would cut way down on the flow though...
And it would REQUIRE a one-way valve too...

Duster · #8 (**permalink**) 08-30-2010, 09:48 PM

Here's some scribbles on those two options...

But I like the first one better...

I think the rim required on the back for the second option would take away too much intake area, and have too little outerwear material area to flow through.

kfx450r#490 · #9 (**permalink**) 08-30-2010, 10:32 PM

ok duster are you saying that the air would be comming in throught the bottom or through the one way valve? im confused on where the water exit will be? i was liking the open rear idea, i was thinking about something like that with an outerwears filter lid that covers it.

and on the testing it could happen, i could send you money and you send me an intake, i know you had alot of racing expectations but that needs to be done because xc racing is hell on you quad!

the utilmate testing grounds

nkeen07 · #10 (**permalink**) 08-31-2010, 01:21 AM

I wouldn't worry yourself too much w/travel. If you can clear full upwards travel w/ the stock linkage then it'd be able to work w/most aftermarket set-ups that guys running an airbox will have. MX guys delete the box and most of us XC guys run stock linkages w/aftermarket shocks, so travel gains are marginal at best.