Swiss Cheese Air Box

[teddy037.2]

Yup.  You can even feel it!   I first cut two large holes in the back of mine (~1.5-inch), because I had the stock paper element and did not want it to get wet.  That was very loud.  When I got the DP ECU I cut-off the entire lid, and switched to a BMC filter element.  Its not as loud with the entire lid cut-off.  I think that cutting holes can make it louder than a completely open lid because of the resonance of the box.

I suppose that's possible. I chopped mine completely, and it didn't appear to be significantly louder up front... 

That's kind of what I was thinking.  Do you have a stencil for my Dremel? 

there's no love in a stencil. it's all freehand 

[johnster]

...except it is.

+1...With the gas wide open the "Oink" (accurate depiction??  )  from the velocity stacks w/an open (or even swiss cheesed i bet) airbox definitely overtakes the exhaust in the dB department.. 

[derby]

Perhaps the old shape from the Ferrari hoods?



Although since they're just going through plastic I don't see any advantage to the shape except looking cool (if its done right.)

those are called NACA ducts.

[ducpainter]

those are called NACA ducts.

Has everyone met derbypedia?    

[Sgt_H]

I decided to try a couple small holes to see if I really hated it or not.  I didn't expect any performance change, and minimal sound difference, but had a little of both.  The inside of  my tail pipe was black before, so if the little holes leaned it out any it was for the better.  I did about 100 miles today and I noticed immediate improvement from the time I pulled out of the driveway.  Not dramatic changes, but it definately registered on the seat of the pants-o-meter.  It was smoother off the line and had a little more kick in 5th gear roll ons.  Not massive, but I really think it was better.  

As for the noise, it was strange.  Sometimes I didn't notice any difference, but other times I did.  It was louder under moderate to heavy throttle, but I didn't think it was at all obnoxious.  I guess I'm one of those who likes the snort.  Tomorrow, bigger holes. After that, maybe cut the whole top off.  [moto]

[Big Troubled Bear]

The bigger the hole the louder the noise

[ricol]

can you tell me where exactly did you cut the hole? Is it at the back of the top lid or front?

I decided to try a couple small holes to see if I really hated it or not.  I didn't expect any performance change, and minimal sound difference, but had a little of both.  The inside of  my tail pipe was black before, so if the little holes leaned it out any it was for the better.  I did about 100 miles today and I noticed immediate improvement from the time I pulled out of the driveway.  Not dramatic changes, but it definately registered on the seat of the pants-o-meter.  It was smoother off the line and had a little more kick in 5th gear roll ons.  Not massive, but I really think it was better.  

As for the noise, it was strange.  Sometimes I didn't notice any difference, but other times I did.  It was louder under moderate to heavy throttle, but I didn't think it was at all obnoxious.  I guess I'm one of those who likes the snort.  Tomorrow, bigger holes. After that, maybe cut the whole top off.  [moto]

[Sgt_H]

I did mine right up front


What I did right; I made the holes bigger.  What I did wrong, I did it with a Dremel.  I should have went and got a drill attachment and cut it out more cleanly.  This is OK since it's out of sight, but I didn't get them very even.  I might still go get an attachment, but I also might just cut off the whole top.

[BlackHills]

If you decide to cut the top off, do yourself a favor and buy a coping saw.  It makes for a quick and easy job and the cut is nice and clean.

[NAKID]

I did mine right up front


What I did right; I made the holes bigger.  What I did wrong, do it with a Dremel.  I should have went and got a drill attachment and cut it out more cleanly.  This is OK since it's out of sight, but I didn't get them very even.  I might still go get an attachment, but I also might just cut off the whole top.

Fixed

[Sgt_H]

Fixed

Doh!  Thanks man

[Sgt_H]

If you decide to cut the top off, do yourself a favor and buy a coping saw.  It makes for a quick and easy job and the cut is nice and clean.

I have a jig saw that I was planing on using.  I figured that would be better after the Dremel turned out to be more difficult than expected.

[ricol]

How's the sound? is it tolerable or you need plugs everytime you ride.

I did mine right up front


What I did right; I made the holes bigger.  What I did wrong, I did it with a Dremel.  I should have went and got a drill attachment and cut it out more cleanly.  This is OK since it's out of sight, but I didn't get them very even.  I might still go get an attachment, but I also might just cut off the whole top.

[Sgt_H]

How's the sound? is it tolerable or you need plugs everytime you ride.

I haven't ridden with the bigger holes yet.  I wear plugs everytime I remember to put them in anyway so I wasn't too worried about that.  One of the other posters said that his bike is quieter with an open box than it was this way, so if this is really obnoxious, the rest of the lid will come off.

[Sgt_H]

Holy crap.  This mod is LOUD.  Not so much if you're cruising, but under acceleration, wow.  It's loud.  My new exhaust is every bit as loud a cored pipes and the box can drown it out completely.  It seems to be loudest at mid-RPM acceleration at over 50 mph. If you're easy on the throttle, it's not a big deal.  If you're cruising, it's not a big deal.  But if you're going to be in and out of the throttle at speed, it's no joke loud.

I couldn't believe a couple holes in the box could be this loud and I was wrong.  I don't hate it. I still think it sounds good.   But if you are trying to play nice in residential areas or the like, think twice.  I'm going to give it some more time before I decide to cut the rest of the lid off but it's a possiblity.