It is a 4:2:1, and has an O2 bung on it.
Here is an OEM 14, 08, dyno run with the corresponding A/F. You will notice that the A/F is a little fat/rich over the bulk of the RPM range. There is the lean 3-4 K portion which is for getting your bike up and going.
A lot of tuners will try and take your bike to static 13.1 across the full RPM range, which may or may not be the best for TTD. So unless they experiment around, it is their best and fastest guess, and what they were trained to do, -dynojet tuners at any rate, and a number of others.
Additionally, some tuners will never get the 3-4/3-5 K bump out.. no matter what. I t can be lowered some. I have never see it flat line like the rest of a custom map can be made.
When you BMC/K&N filter your bike and put on an after market pipe, you will actually provide more O2, and thus lean out the A/F a little, which is better. You will gain about 10 HP on top end (very top speed MPH), and a reasonable bump of TQ in that 3-5 K range, and highest in the 3- 4 K RPM , without remapping.
Remapping is acutally tuning a bike for best TTD (racing), rather than a static 13.1, IMO, or for a smooth transition across all of the RPM/TP ranges with a smoother A/F ration = smoother throttle response. Works better/more noticable on 2 cylinder bikes.
This bike is so fast, you'd likely never notice it, unless your map was waaay off to begin with, and that I suppose could happen, but I have not seen it happen. After over 300+ runs, I quit remapping after air filter and pipe changes, as it was a waste of $$$ and no gain.... well have gained a few HP one it is 'dialed' in.. if a few HP is worth $$$.
If I were going to the track, I'd likely remap for best TTD if drag racing/winning was my thing.
* Last updated by: JDC on 3/13/2009 @ 10:39 PM *