Since there's so much talk of the muffler, resonators, and airbox, I thought I'd post pictures of mine! I modified the stock airbox by "ventilating" it with a hole saw, taking into account heat sources so as to keep as much cool air coming in as possible without giving up too much flow.

Here's a shot of the stock resonators (20lb. each!) behind the bumper:


And the suitcase muffler (25lb.!, with a key beside, for size comparison):


The air silencer (3.5lb.) outlet into the airbox:


The air silencer inlet:


The air silencer restrictor inside:


K&N filter in place (I didn't modify the airbox lid):


Modified airbox top view:


Modified airbox front:


Modified airbox side/rear:


Modified airbox bottom:

 

Thanks billapex, the photos really are helpful in seeing just how much weight is in the stock exhaust. Seeing the air restriction, it probably doesn't make much sense modifying the exhaust without taking care of the inlet side first.

 

the one thing I would be concerned with with all those holes in the box is that you will be sucking in a lot of hot air from the engine where as with just the stock hole on the bottom you are sucking in cooler air.

 

That's why I didn't drill any holes on the engine side of the box. I noticed only good things from my drilling modification. And hey, it's 106 degrees here today, so I'm not that concerned with "cool" air. [:@]