Aurora 4.0 Airbox Mods May 6, 2004 19:28:57 GMT -6
Post by JimW on May 6, 2004 19:28:57 GMT -6
You know you want it!
Here is the best page on how to do the Aurora 4.0 airbox mod, typically for the 95-99 Classic models
Writen by Greg Garnes
The first picture is a self explanatory side by side of my extra stock air box and the modified box. Note that the ribbing across the top of the box has been removed and most of the bottom of the box has been removed to eliminate the "waffle pattern" on the bottom of the box. When first posting this modification, I mentioned that I would make these additional improvements to eliminate any turbulence they may cause. I dyno'd these improvement and found that they did not add any significant power. I also tested the performance with the original side air inlet blocked so that air would be pulled from the bottom only - thinking that maybe air entering from two different direction might cause turbulence. This decreased the power a little, so I guess just leaving both openings free is best.
The second picture is a close up and shows that I gasketed the bottom piece with some common weather stripping.
The third picture shows the existing bottom hole that is utilized for more air flow when opening up the bottom portion of the air box. Conclusion - Simply removing the top liner and opening a hole in the bottom portion to expose the existing opening below the air box is all that is needed to maximize the air box performance. The additional cutting and removal of the "ribbing" and the bottom "waffle pattern" did not add much power, if any, at all. Also, in making these modifications, make sure that no plastic "crumbs" will flake off and enter the engine from the top (clean air) side of the box. Sand things smooth, and use a heat gun if needed to consolidate any rough or "fuzzy" plastic.