Hi! I was wondering if any of you have modified their K1300R/S bikes for a little more performance, and if so, which things did you upgrade? I have looked at Power Commanders, Quickshifters, Air filters and I also found something called a "Booster Plug" (which I have never heard of before), and I was wondering if any of them are worth the cost. Note that I live in europe so exhaust modifications are not really on the table, unless they are legal of course, but from experience most of them aren't. I am also not really looking for things like turbos and superchargers, I'd like to keep the (excellent) reliability and resell value of my bike fairly close to stock.
My goal would be to get around 10-15 additional hp out of the bike without having to sell a kidney, thanks in advance for any suggestions!
Late reply here, hope it is useful. I have a 2014 K1300s Motorsports, and I can relate my experience with a few of your questions.
Booster Plug: First, the booster plug. It will not give you more horsepower overall, but it will give you better low-speed driveability. Let me explain my experience with my then-brand-new K1300s. When I first got the bike, I was plagued with low-speed driving issues, primarily stalling and ... non-responsiveness at critical times. There were two issues, in addition with getting used to the clutch. First, the bike was tuned so lean (stock) that it sometimes would simply do NOTHING at low speed when I tried to engage the clutch and feed it power. That is, start slipping the clutch and feeding throttle, but the throttle simply didn't respond, the clutch was let out and the bike stalled. This is SO EXCITING when it happens doing a left turn from a stop in traffic. I actually quit doing left turns without a massive gap in traffic. One reason was that the throttle cable was too tight, and it would respond differently depending if the bars were turned. (Lots of fun doing u-turns.) Put the proper amount of slack in the cable, and at least the engine wouldn't speed up because I did a u-turn.
The other issue was that (I assume) BMW tuned the bike lean for emissions. Two symptoms: poor and (wildly) inconsistent throttle response at low rpms, and a pronounced flat spot at 5,000 rpm under full acceleration. I bought a Booster Plug to address this, and I had a mechanic install it into the air duct behind the air filter so that the plug would stay clean. This immediately cured the inconsistent low rpm fueling - no more stalling! - and it mostly fixed the flat spot at 5,000 rpm. Highly recommended.
That said, an alternative which solves the driveability issues AND gives more power is a Power Commander or similar ECU change coupled with a dyno mapping can do what you want in terms of increasing maximum horsepower. These are two solutions that keep the bike near stock and shouldn't cause a downside while providing some upside. I suppose the legality of ECU changes may run into emissions issues, but that would be specific to mods done and location of bike.
Other performance changes? None here, really. If anything my changes all slowed the bike down, because I added weight. I put on a centerstand, which gets used a whole lot less than I expected, but which was a godsend when I had a flat rear tire on vacation. (Could not use the sidestand with a flat rear - the bike was too low to lean over.) I did put on a semi-decent Fiamm horn to replace the 'meeper', but I should have put on a pair of Fiamms, assuming they would fit. I added a pair of Grip Puppies ($12) to soften the grips, reduce vibration, and make them larger in diameter to better fit my hands. I had the Hot Start Issue where sometimes the bike would simply die when I pulled in the clutch (before Booster Plug), and then the bike didn't want to restart for a (short) bit. The fix was done under warranty and consists mostly of a thicker cable to the starter motor.
I added a tank bag, luggage rack ('grid') and Sport saddlebags. I changed the seat to a Corbin heated seat. I found that the wind ripples on my chest severely when over 70mph with the tank bag mounted, so I added a small waist bag onto the tank bag itself and rotated it to fit between my belly and the tank bag. Suddenly the rippling stops as the air flow is changed that cause it. And I can simply rotate it to the front of the bag if I want some breeze down my chest in the summer.
And I put a radar detector into the tank bag, hooked its output to a Sena SM10 which bluetooth's the signal into my SC2 on my Schuberth helmet. No more pesky wires or earplugs to deal with.
When I first rode the K1300s - after 30 years on a 1985 K100rs - it scared me with the power and speed. I couldn't figure out why someone would want even more power. Well, after 8 years I can see it now as you simply get used to what you have. But riding the K1300s is an exercise in throttle self-control 99% of the time. I usually only give it anywhere near full power for more than one gear on freeway in ramps. In virtually every situation you have to exercise wrist control. It almost always has too much power to give it 100% throttle for more than a couple of seconds.
I did change the tires, obviously, as it ships with old tires (M3) long since obsoleted with modern dual-compound tires. I first went through 4 sets of Pirelli Angel GT's and am now on my first set of Angel GT2's. They really inspire confidence. I might add that I find steering precision a bit vague at stock 36/42 psi settings. I prefer 38 psi in the front, which makes it much easier for me to steer the bike precisely, like following a 4-inch-wide tire track through a gravel-covered corner or precisely hitting the spots you want your tires to go.
I've had the bike to 165 a couple of times, and that is with the tank bag on (radar detector in it!) meaning I can't lie flat on the tank. My helmet was shaking so much at speed that it shook my glasses and caused blurry vision, so I backed off before it would pull redline. I've been to 150mph several times with tank bag and saddlebags, and even with passengers. I really don't need more speed I can't use, but I could see a bit more acceleration being even more fun.
