Member Contributer HighSideNZ Posted June 22, 2015 Member Contributer Share Posted June 22, 2015 Looking at going down this road for the 825. What I've found are 40mm DCOE Weber trumpets 20mm long. These will be the "short" ones and I'll mod the standard short VFR800 trumpets to act as the secondary unit. Link to comment Share on other sites More sharing options...
keef Posted August 25, 2015 Share Posted August 25, 2015 would these trumpet filters work for the big air box mod, so you dont have to mod the airbox- except for removing the filter? Just slip them over the stacks? http://www.burtonpower.com/pipercross-air-filter-trumpet-socks-universal-pair-c1050.html Link to comment Share on other sites More sharing options...
Member Contributer HighSideNZ Posted August 25, 2015 Member Contributer Share Posted August 25, 2015 Hi Keef Don't think there would be enough height to get these within the airbox. I've done a similar mod with the K&N filter as what Mohawk outlines in this post. There is a small difference between the Gen5 and Gen6 airboxes but it is completely doable. I used to use sock type filters like these on MX bikes modified for Grass Track back in the day. You need to be able to use the entire sock area to pass enough air. One thing I did do as I was making up the airbox top with the cut up K&N was to measure the pressure drop across a standard Honda paper filter and the K&N at the same RPM level using an electronic manometer capable of measuring down to 0.1mbar. Stuck a 4mm nylon elbow in to the side of both of my airbox bottoms, below where the filter would normally fit. What I found what that at 5000 RPM the paper element showed -0.2 mbar pressure drop across the filter. The K&N, at the same RPM showed -0.1 mbar drop. This was a brand new K&N filter straight out of the box and plastic bag. So they do pass more air as they say they do. Just thought it worthwhile proving once and for all. Cheers Phil Link to comment Share on other sites More sharing options...
CandyRedRC46 Posted May 10, 2017 Share Posted May 10, 2017 This is some good stuff. Link to comment Share on other sites More sharing options...
Lint Posted May 15, 2017 Share Posted May 15, 2017 Since this thread lost all of it's pictures in The Purge, anyone have any visuals on what was actually done? Link to comment Share on other sites More sharing options...
RVFR Posted May 15, 2017 Share Posted May 15, 2017 Photos in the first post by Mohawk with links are view-able. Link to comment Share on other sites More sharing options...
Member Contributer Mohawk Posted December 13, 2017 Author Member Contributer Share Posted December 13, 2017 On 19/09/2014 at 12:02 AM, Rush2112 said: What length are your "short" Velocity Stacks? Are they modified VFR V.S. or from another bike? Just reviewing this as someone asked about it & noticed I failed to respond to Rush's question. The short stacks are stock Honda ones, cut off flush with the base of the mushroom head. I then scored up the underside of the mushroom part, the fitted two steel pins throuhg the bolt hole bosses then filled the whole underside with car body repair putty & clamped them down on baking foil until it set, to get a flat bottom. Then used double sided sticky tape trimmed to fit & stuck them to the airbox base with a little filing to ensure no lip between them & the airbox base. Then bolted the airbox in place. Still going strong thousands of miles later & still revs beautifully. Link to comment Share on other sites More sharing options...
Member Contributer Dutchy Posted December 13, 2017 Member Contributer Share Posted December 13, 2017 Hi Mohawk, none of your pictures in the OP are visible unless one clicks on the icon. What you could you (and I did for my older posts) is go into edit mode, you will see them iin the panel and (re)insert in post again for each pic. Link to comment Share on other sites More sharing options...
Member Contributer Mohawk Posted December 13, 2017 Author Member Contributer Share Posted December 13, 2017 5 hours ago, Dutchy said: Hi Mohawk, none of your pictures in the OP are visible unless one clicks on the icon. What you could you (and I did for my older posts) is go into edit mode, you will see them iin the panel and (re)insert in post again for each pic. Sorted :) Link to comment Share on other sites More sharing options...
Lint Posted December 14, 2017 Share Posted December 14, 2017 Has this been ridden in the rain? I'm thinking of giving it a go, but I'm concerned with water getting in the engine, either when riding in the rain, or washing it. Please let me know. Link to comment Share on other sites More sharing options...
Member Contributer Mohawk Posted December 18, 2017 Author Member Contributer Share Posted December 18, 2017 Hi Lint, I have ridden it like this in a tropical downpour, I mean in rain that I have have only seen a couple of times in my life. I got wet in waterproofs I never get wet in, before or since. I have a ramair inlet above the oil cooler & below the cross rad hose, it has a stone screen on it, but that is all. Look at this diagram, the air enters through the intake, hits the ramp, where most water will end up as it is heavier than air, then the air travels up the front of the airbox. There are hollows in the back of the headstock area with a bracing plate across the middle, these serve as air an reservoir making the airbox bigger & also slow the air, so any water that stayed in the air stream & missed the ramp, will fall out of suspension. The air then turns over the top of the airbox & into the filter (purple on this diagram). The yellow represents the seal which seals the tank to the frame & the tank to the airbox. The sides of the ramair parts & the sides of the airbox are also sealed to the frame, so air coming in the intake can only go to the engine. So as you can see rain falling can't get below the tank & air entering the intake has to make a few turns . Also bear in mind that the air is NOT technically moving, its the air in front of the bike being scooped up by the intake from a high pressure zone. Imagine the ramp is like your car mirror, rain hits the side facing forward, then drips away, whilst the back of the mirror generally stays clear. There are a couple of small holes at the bottom of the ramp to allow water to escape. The only thing that can mess this up, is the tank filler drain, so make sure your hose is still attached to the bottom of the tank, otherwise rain falling on the tank filler will run down through the drain & empty onto the filter ! There was a thread a while back about a guy that had fluid lock every time he parked his bike in heavy rain. I'll put money on it being that he had lost or had a perished drain hose & that spout is directly above where the snorkel enters the airbox & I know he had no snorkel ! Enjoy :) Link to comment Share on other sites More sharing options...
Lint Posted December 21, 2017 Share Posted December 21, 2017 Thanks Mohawk Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted December 21, 2017 Member Contributer Share Posted December 21, 2017 +1 Always enjoy reading your post Mohawk... Link to comment Share on other sites More sharing options...
SlimWhitey Posted January 16, 2018 Share Posted January 16, 2018 I'm astounded that none of those nuts caused your engine to eat itself. I've got a friend or two that really regrets the setup of their air filter after having a race engine eat itself mid-lap. I don't like the effect of moving the torque further up the band, or I'd likely do this. However, I'm interested in how you got all the weight loss in there. Weight is the devil. Link to comment Share on other sites More sharing options...
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