If you're going to put a full exhaust
on that thing, you should definitely consider remapping the FI to accomodate the high performance pipe. It will create a leaner condition and remapping the FI is an almost must. The FI on the KX is open loop, which means it's not going to automatically adjust for the new exhaust like a closed loop FI would. You can actually get
more performance out of the KX by tweaking the FI than you can with just an exhaust. It's pretty amazing what that little computer can do.
The PC and FMF
pipes are both great. I run the FMF
4.1 RT w/ Megabomb header for moto and the Powerbomb
header for off-road along with two different FI mappings for each condition.
A few shops usually have the FI calibration kit and will remap the ECU for you for usually around $50 or so. You can also just mail the ECU to a place like Precision Concepts and they'll remap it for $69. They've done a bunch of testing and have good maps. That's what you're paying for... lot's and lot's of testing. It's a 5 minute job. AS Racing has a drive-up FI calibration kiosk at his shop in Santa Clarita. Now that's cool.
Edited by Justin Hambleton, February 23, 2012 - 05:45 PM.