Interesting that you needed it mapped. With the cats in place i wouldnt of thought the slip ob makes too much difference. Espescially not with the pipe being roughly the same size as a standard one
You have to remember that fitting the Akra removes the exhaust valve (HTEV). The ECU is still expecting the exhaust valve to be shut up til about 6k rpm. (The ECU doesn't know that the valve actuator it's turning is no longer connected to anything!)
Ahh right makes sense. All my previous bikes (mostly suzuki) have had the valve before the end can. Will it really make the bike that crap to ride about?
I didn't find it crap to ride about. I always found the bike a little snatchy at low revs anyway and the akra hasn't helped this but I can imagine that with a power commander it would really open the bike up. Sounds awesome though!!
The valve is before the end can... it is in the "link pipe", but the OE exhaust and "link pipe" are one unit. The Akra is separate end-can and link pipe... but regardless, the exhaust valve gets removed. FYI - to save more weight you can replace the exhaust valve servo motor with a "Servo Buddy"... frees up a little room under the seat too, handily big enough to fit a speedo healer. Anyway, I can only speak about my own experiences... I replaced the OE filters with K&N, and replaced the OE exhaust with Akra at the same time. With baffle in, it was OK, but the flat spot just before 6k was quite bad. You certainly did not want to be exiting a roundabout whilst in the 5-6k range, as you had no idea whether you would get any drive.... or too much drive! With baffle out though, it was just ridiculous. The power-delivery below 6k was all over the place. Once you got above 7k it was fine. HOWEVER... that is only half the story. With a bike that is now breathing more freely, you are likely to be running a little lean, which is dangerous. Piston-burning valve-melting dangerous! If you value your engine you will want to find the money to get a Power Commander. The Power Commander website has a map for the bike with Akra fitted, and that map isn't too bad... certainly a LOT better than no map, so you don't have to fork out for a custom map straight away. After a custom map though, my bike is now turbine-smooth!
Wont the 02 sensor in conjunction with the ecu adjust the fuelling for something as minimal as a slip on? I can understand for a full system but exhaust servos are there for noise pollution no?
To an extent, it can compensate for the extra breathability of the aftermarket exhaust. Are you familiar with the difference between open-loop and closed-loop fuelling? And yes, the exhaust valve is ostensibly there for noise, but it also restricts flow which the ECU needs to take in to account. And the ECU cannot know that the exhaust valve has disappeared.
Nope... it's a single allen-headed grub screw. A little fiddly to avoid dropping the grub screw when re-fitting the baffle, but 10 seconds work!
