air box question

I experimented with removing the air box door and it felt like the engine was getting a lot more power at all speeds. Could one cut open the top of the air box to achieve the same effect? This would lessen the chance of getting the filter wet during stream crossings. Could this hurt my engine somehow? BTW, I am not keen on removing he AIS for environmental reasons and the chance it might burn up the catalytic converter. Thanx.

motobuck wrote:

 BTW, I am not keen on removing he AIS for environmental reasons and the chance it might burn up the catalytic converter.  Thanx.

Modifying the intake will also affect emissions/environment as well.

If you are really concerned about environmental issues and longevity of the catalytic converter then you are best to leave the airbox stock.

If you cut open the muffler and remove the catalytic converter then there is no reason to worry about removing the AIS.

If you haven't done it already you may want to look at changing your gearing. Many just drop a tooth on the front sprocket (13 to a 12) and that will give you a good feel for what that will do to the bike without having to buy a new chain. However some will say that running a 12 tooth front sprocket will increase the wear on the chain slider so many opt to keep the front 13 tooth sprocket and add about 3 teeth to the rear sprocket along with a longer chain.

Right now I am running 13/48 gearing and seem to like that the best. My two friends with WRR's are running 14/48 and 13/47 and both seem to like their own setup.

You can do the "ultimate airbox mod" to give it a bit more air pretty easy, this keeps water out just as good as stock, if you do a search you will find lots of pics of this mod.

I remove the flappers actuator, stick a drift through the hole it leaves and hit it with a hammer, this removes the entire flapper in minutes which is way quicker and easier than what the guy who named it the ultimate airbox mod did.

You can also cut a hole in the airbox above the airfilter to give it more air, oddly this area is protected from water better than the stock opening, I have a 2 1/2 by 2 1/2 inch hole there on mine. I ride a lot of wet/muddy trails and get some water splashed onto the stock airbox opening but never get any near the hole above the filter.

I have a programmer and fmf pipe to go along with the extra air the motors getting, I never tried it without a programmer.

Some guys run with modded airboxes with otherwise stock bikes with no issues, I don't think you will hurt the motor as im not adding any extra fuel at wide open throttle with my programmer anyway.

Rsteiger and Biglake: thanks for your input about the air box modifications. I realize that the AIS removal has been talked to death, but I haven't found much conversation about simply cutting a hole in the top of the air box. The bike is stored for winter, so it will be spring before I try anything.

BTW, Bob, I did change the stock gearing to a 13/47 set of sprockets with a 112 inch chain. Definitely better for the steeper stuff. Thinking about trying a 13/50 combo.

Motobuck

It's sometimes hard to find all of the old info on these mods.

You can look here for the "ultimate air box mod" evolution from HighFive.

http://www.wrrdualsport.com/index.php/techguide/airintake/77-airboxmod

I did something similar to this:




Basically gut the part where the flapper goes, which leaves a nice big unrestricted opening for air to enter the top, but still provides protection from water intrusion.