When I bought my bike, I knew I was getting a great bike with a few perceived flaws; and that playing with it / modifying it was half the enjoyment. Depending upon the year and the mods most of us are doing, the bike runs anywhere from 135hp to 165hp, with varying power curves, and the bike may or may not have a flat spot in the 3500 – 7000 rpm range.
Now some would argue the OEM exhaust looks good, sounds fine and works as expected; and the bike is a beast right off the showroom floor – and I would agree. But…………… this is an exhaust thread.
Arrow: The fit & fitment with the Arrow headers is superb – absolutely superb. Everything hooked up easy and tight. I added the Holeshot 10” Bad Boy Comp exhaust can with mid-pipe. Bike ran buttery smooth at idle, no hunting nor surging; and power throughout the rpm range was noticeably better. The bike went from a beast to a nasty SOB of a beast.
M4. Took the Arrow off last week and installed the M4. The fit & fitment is not as good as the Arrow. I did pay particular attention bolting the header to the engine, and happy to say – no leaks. I had to add washers / spacers and a longer mounting bolt as the exhaust and the can did not line up well. As soon as I started the bike – I noticed the hunting / surging others have mentioned. Out on the road, there is a detectable difference in the 3500 – 7000 rpm range. Dramatic – no; noticeable, yes. So now the bike has gone from a beast, to a nasty SOB of a Beast, to a slightly nastier SOB of a Beast.
Next step. I am having a custom mid-pipe made so I can reinstall my Holeshot 10” can. I am hoping / guessing that adding the 14” – 15” mid-pipe with the can will smooth out the idle. Once installed and tested I will report on it. Will also hit the dyno shortly after that is done and will share.
For clarity, my mods include:
K&N Filter, Restrictor plate removed, PAIR Block Off Plates, EVAP Removed, O2 sensor removed, Exhaust Valve & Actuator Removed and a full Dano’s Flash.