Mo Lee
MOgang Member
Sorry but the best I can tell this only applys to the GS/RS up thru 2012. In my quest for faster times this year at Spyderfest I had intentions of building a ram air airfilter for my Spyder during disassembly I noticed this part in the air box I had not noticed before. For the life of me I can't understand it's purpose other than a factory restrictor plate as in NASCAR. with this in place you only have two roughly 2 inch holes for the air to enter the air box, with it removed you get around a 3x5 hole for air flow. With the original air box still in place you still get the advantage of cool air flow into the intake unlike the after market air filter conversions that are pulling their air from around the engine (hot air). My 08 GS has been running an HMF muffler since the 1st year I owned it and has always had popping on decel, I considered 02 modifier, juice boxes, and other enrichment devices but never read good enough reviews to convince me. By removing this from the air box my butt dyno says it runs a lot better and virtually took out all of the popping from the exhaust. My times only improved slightly however I was having a terrible time getting enough traction off the line this year. Like I said I'm not sure of the purpose of this chunk of rubber, maybe water control or noise control but mine has become a permanent wall decoration. So not only is this mod free it also leaves you a very artful looking chunk of rubber to hang in your ManCave.