Originally Posted by bluesman
The really cool solution to whole airbox stuff on DR (something I did not have time to do to mine - it was next planned mod but sold bike) is to remove battery box. Relocate battery to front of bike where sump guard is. Move CDI and RR to frame head (just like they did for rally bike) and create very large airbox by using space free from all that clutter. You may be surprised but it is not hard job to do. I even pre-fitted new setup and god larger battery (16.5 Ah) but...as I said, sold the bike.
Using that metod will allow not only to run large airbox, preventing need for large opening. It will also allow to use one of standard flat filters like in cars making it cheaper in the long run.
This is a really good idea. A large airbox is capable of making more power than a small one that has been opened up, especially if it has been set up as a properly tuned Helmholtz resonator. And the lithium ion batteries that have become available in recent years definitely help with regard to relocation.