I did a few parts swaps on my bike to see if I could improve the power delivery in the mid-range of the RPMs. I installed a Tyga header, an exhaust, a DNA filter and a Powertronic. Without opening up the airbox, there was some improvement in throttle response at the top and bottom end power but the mid-range was still a little lacking. Because the Svartpilen has a different airbox than the pre-2017 KTM 390s, the open airbox lids from companies like MNNTHBX are not currently an option. According to other forums, that mod really improves power delivery throughout the rev range.
The standard airbox has an intake that is an oval of about 2 inches wide. To try to get more air into the system I went ahead and drilled some holes in my airbox. After a few rides and alot of WOT runs, I think it works pretty well. Mid-range power is definitely up and compared to before, there are no flat spots in the rev range at all. The bike now revs all the way up to the rev limiter with no hesitation. I’m using the standard Powertronic performance map.
There are a couple of side effects to this mod. On WOT, intake noise is greatly increased. This would be the same with any open airbox mod. When cruising, I didn’t notice much sound difference, just WOT. Secondarily, the bike seems to have a little more vibration at the handlebars. I’m not sure if this is me imagining things due to the increased intake noise or if it is real but it feels like it vibrates a little more.
To drill the holes I simply removed the battery. I don’t even know what size bit I used but I went larger to avoid any whistling sound that might arise from smaller holes.