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DPW

Airbox Port L&M Mod

15 posts in this topic

Yeah, Lightspeed is working on a fix for the small air intake inlets into the airbox. It is supposed to help the engine rev out more even in it's stock form. Not sure what it will entail just yet.

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fine and dandy on a indoor sx bike.

mx that would be an issue.

offroad that would be a MAJOR issue. hey look water can get a straight shot to the valves as well!!!

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Yeah, Lightspeed is working on a fix for the small air intake inlets into the airbox. It is supposed to help the engine rev out more even in it's stock form. Not sure what it will entail just yet.
I'd be surprised to find that there was anything to it at all. The two air inlets that are already there are each roughly twice the size of the throttle bore, meaning the total inlet is about 4 times as large as that. Cutting out the sides of the inlet shrouds, or slotting, or whatever will not benefit the engine in any way unless the current inlet creates a pressure drop at the opening. To make any improvement at all, anything done would have to cause an increase in air pressure in the plenum directly below the filter element at full throttle.

If I were to open up the air ducts at all, it would be at the lower rear corner, so as to let dust blow straight through and out, while the intake air made its upward turn.

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While I don't think this is what they are after...air box resonance can greatly add power in a narrow band.

Changing the inlet holes and quantity etc...can effect this.

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Considering the layout of the intake tract, the major, primary component effecting resonance is the plenum (open, wider volume) above the end of the intake horn of the air boot, below the filter. This is the effective terminus of the intake tract, and the most change in its resonant character would be made by altering either its volume, the material from which it is made, or both. Changing the inlets remote from this will have some small effect on this, but very little.

And, as you mentioned, it's only effective within a narrow range.

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MXA complained about how small the intake into the airbox was in relation to the space around the air filter. Light speed is working on a modified airbox for Yamaha and will probably make it available to the public.

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Just seems to me that it is all just someone trying to sell something. The bike was what 5 years in the making don't you guys think the Yamaha engineers would have solved the problem if there was one. . .also Larry Brooks is a tool and prob just out to try and sell something.

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cycra will prob have nice shrouds designed for better flow and notas costly as a carbon fiber air box.

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For us mear mortals i would think the bike has more than enough power out of the box.

I am in no hurry the cut the shrouds up for more air, i kinda like the way the air filter is protected as it comes from the factory.:banghead:

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The bike was what 5 years in the making don't you guys think the Yamaha engineers would have solved the problem if there was one. . .

You could say this same thing about almost every new mx bike when it comes out. History says otherwise.

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Looks abit rough from the L&M boys. Could of put some gauze there or something.:banghead:

I guess they thought that Stewart would be up front. As for me I would need to keep it stock:smirk:

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