Ok, well we're halfway through the season and I'm 6.5 points off 3rd place. I've got 6 weeks till the next round so ideas are racing around in my mind to get every last bit out of the engine in my K7 gixxer 600. I have already decided to go for total loss but I will test that on the dyno first just to make sure it doesn't somehow make a decrease. With two 4 cell A123 batteries I believe I should get 25-30 mins of running and seeing our races are at max 15 minutes I am prepared to risk a red flag etc. I did toy with the idea of removing the rotor altogether but can't be arsed having to push start or get some rollers, not to mention probably decreasing the crank mass too much. So what I want to know is if anyone has taken some meat off a rotor on the lathe and seen how that worked out? Did it change the throttle response much? I assume it makes it easier to spin up when at full lean but should give some good acceleration gains? Maybe I'm barking up the wrong tree but every last bit counts
Gah! Sorry for being ambiguous. I mean the ignition rotor, that bolts onto the crank. Not the brake disc...
yes. you can get rid of (machine away) the outer portion of the rotor and still have the tapered mounting area as well as the starter gear.
On my 07 gsxr 6, I found an 8 cell LiFe battery would barely do 27 minutes, on a total loss setup. That's running a stock motor, using a jump battery to start with, also having to run a PCIIIusb, and a stand alone Cordona PQ8 quickshifter. In my experience, if you look at the run time from the moment you start the bike, then leave the pits for pre-grid, then a warmup lap, then get everyone gridded, THEN do a typical 15 minute sprint, your motor will be dying just as you approach the finish. If you have a red flag restart, you're screwed. A 12 cell only weighs 12 oz's more, and gives you a margin. Even then, if a gnarly red flag event sends everyone back to the pits for a few minutes for track cleanup, you need a backup plan (battery).
Yeah that is the reason I decided against running it up till now. The 15 minute includes warmup lap etc. The races I do are 10 laps and the two tracks I will be racing at have lap times under 1:20. So 10 laps from standing start going on last years race times is just under 12 minutes. Add in a warm up and warm down lap, another 3 minutes and then say 5 minutes of waiting in pit lane etc and you have a bit of leg room, but not much. Yes another A123 pack would be lovely but I already have 2 sitting in the garage (one in bike and one on my bench) and the budget is a bit thin. How do you hook up the other battery for starting? I plan on rigging up a quick connect for the charger, can I just get the extra battery and plug in there? Or do I need some relays to isolate the starting battery from the other batteries?
The starter is gonna pull a lot of amps, so you can take the seat/tail off and jump directly to the terminals with jumper cables or other heavy gauge cables, or better yet, make your quick connect with at least 12 ga. wire (8 ga. is better). I use a regular OEM battery to boost with. The LiFe battery doesn't need the boost, the jumper battery is just to save some of the charge in the LiFe. Almost forgot: be sure the booster battery is fully charged.
Yeah cause if the OEM has lower voltage than the bike battery they will try to charge it! I was just going to use the plug that I will connect the main battery to the charger and swap that to the OEM battery that can supplement the A123's when it is idling. But hadn't thought of the extra current that would fry the 2mm cables I will use for the charger! I have a datalogger (which records voltage) and a day to test the theory before racing and if it shows any signs of being a failure I will just put the altenator and reg/reg back on and move onto the next idea. Still wanting to hear of peoples experiences with lightening the rotor. I have a spare one so it's no major loss if I have to chuck it in the bin.
Here's a good thread about total loss/ rotor removal. In reference to an R6, but the logic works with any brand: http://forums.13x.com/showthread.php?p=2614649#post2614649
You can machine off the outer portion and then install just the center assembly. That way there you lose the majority of the weight of the flywheel but still have the electric start. Or if you have the $$ you could go with this -
Yeah that is what I was thinking. I don't want to go too far and then have a really hard to ride bike though. I was after some feedback in regards to that. Surely someone on here has done some experimentation. I have access to lathes etc so it is not a problem to do that and seeing as I have a spare rotor I don't have a heap to loose. Another thing I was thinking. Is it possible to setup a plug so you plug in the oem battery just to the starter motor (via starter relay I am guessing) and then have the other batteries independently run the ecu, injectors etc. That would mean they don't loose any charge at all starting the bike but if you stalled it then it's crash start :up:
There is a guy on tl planet that has taken 500 grams off of his tl rotor. He was saying it is ok for racing, but would make it impossible to ride in traffic on the street. I have been thinking about doing the same.
Yes, that is the simplest way to go. Find an electrical supply (industrial) or electric forklift battery plug and simply wire positive of the jumper battery to the battery side of the solenoid and the negative side to ground. Then plug in the jumper and use the existing start button. You shouldn't have to isolate the on-bike battery from the solenoid, but you can if you want to. We did this with our total-loss bikes, worked a treat.
But the on-bike battery feeds the entire electrical system thru the starter relay assembly. If you hook up a jumper as you describe, you're essentially wiring the jumper battery in parallel with the on-bike battery, a situation he's trying to avoid. The on-bike battery would have to be isolated somehow. Here's another idea: isolate the starter motor. Disconnect the starter motor from the starter relay, and hook up a jumper quick disconnect to the motor. The other side of the jumper connects to an off-bike starter battery, with a pushbutton starter switch (like a Moroso 74120) inline on the positive lead. You hook up the the starter battery, turn on the ignition, hit the jumper starter button (the start button on the bike won't work anymore), and fire it up.
Fair enough, but if the jumper battery is larger than the on-bike battery, it shouldn't affect the on-bike battery to a great extent. I was going to try to explain how to isolate the on-bike battery, but I made it too complicated. You explained it very well, as opposed to how I was trying to type it up.
