So this Friday is the last open night at the local drag strip around here, and a bunch of guys from work are going and talked me into joining them. First of all, they require a lanyard kill switch so I was wondering if anyone has installed something like this before. I have access to plenty, and I just planned on cutting the wire to the stock kill switch and putting some bullets on and running it to my lanyard switch. That way it's easily swappable/reversible. Unless anyone has a better idea. Also, does anyone know if the stock switch goes to open or closed when it's off?
The kill switch applies power from the 10 amp starter / bank angle sensor fuse (White / Black wire) in the fuse box. The best place to find it is in the headlight bucket. Look for the Brown 9 pin connector, cut the wire on the harness side of it, splice in about 18" of wire to each end, wrap it in tape, and feed it out the back of the bucket. The usual location for the lanyard switch is on the handlebars, so be sure the wires are long enough. Oh, the kill switch is closed in the run position.
Second, any advise would be helpful, it's just friendly, and most if not all of them will be in cars. But one of the guys cars is gonna be as fast if not faster than my bike and bragging rights mean a lot. Suggestions on slight suspension tweaks for a better launch, tire pressures, shift points etc...
Standard stuff here:
-- Set the rear preload to its lowest position, and if available crank up the rear compression setting. This lets the rear squat (preload) and slows the rise under hard acceleration.
-- Run the front tire at around 28 to 30 PSI, and the rear ... well, its a "run it and see" situation. Start at ~25 PSI and if on the launch the tire wants to go up in smoke drop the pressure to put more tread on the track. Seems to hook up too well? Raise the pressure. It'll tell you what it prefers. Remember the best acceleration is when the tire is running at about 10% slip, though you may not have enough runs to dial that in.
-- A typical amateur launch usually entails tagging the rev limiter and slipping the clutch until it's fully engaged, usually just before hitting the limiter again. In the case of a 919, however, this wastes time, attention, and clutch plates.
A proper launch takes advantage of the torque curve put out by the motor, which hits a peak around 5,000 RPM. The best launches I have done start with sitting back to weight the rear tire, get the clutch fully engaged as soon as possible, then nailing the throttle while feeling traction and adjusting body position forward to keep the front end down. Wheelies waste time.
The 1-2 shift seems best around 8,500 RPM which drops revs back into the meat of the torque curve: just under 6 grand. As practically everyone who rides a 919 will attest that 1-2 shift can be problematic due to the deep neutral detent -- a good deliberate push on the lever is necessary to make sure you don't look like a doofus with a wildly revving motor and grinding gears.
The 2-3 shift should be at ~9,000 RPM, dropping revs to 7,500.
After that it depends on how far away the finish line is: 9,500 RPM in third gear (with stock gearing) is right around 105 MPH, and by then you should be close to the eyes. It's up to you whether another shift is worthwhile.
Remember your biggest advantage is that of weight: you have considerably less mass to get moving, so most of any lead you get will be at the start. After that all you can do is ride as clean as possible and hope he can't "haul you in".