Author |
Message |
Acab
| Posted on Wednesday, April 12, 2006 - 09:01 pm: |
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Anyone know where rev limits on an XB12S are? |
Fullpower
| Posted on Wednesday, April 12, 2006 - 09:37 pm: |
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6800 hard. soft limiter can reduce rpms below that after a while at max. |
Shea
| Posted on Wednesday, April 12, 2006 - 09:42 pm: |
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Never felt the need to take it passed 6200RPMs to be honest. I hit the yellow area, then shift. Power drops so hard in the yellow that I don't see why one should drag it out. |
Acab
| Posted on Wednesday, April 12, 2006 - 10:22 pm: |
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thanks guys |
Blake
| Posted on Wednesday, April 12, 2006 - 11:19 pm: |
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Power should not drop in the yellow zone. Peak HP is at or right near red line on virtually every Buell I know, for sure the XBs. |
Buellgirlie
| Posted on Wednesday, April 12, 2006 - 11:28 pm: |
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just follow the power band and shift when you start losing power. i dont really remember the exact rpm that is the hard edge where power cuts off , but it definitely will do that. i found it a couple times out with some hondas last weekend....its somewhere around 7000? D |
Shea
| Posted on Thursday, April 13, 2006 - 10:15 am: |
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Well, I'll try it today and see what happens at 7000RPMs, but perhaps because my bike only has 800 miles on it, that's the reason why it drops off there. |
Spike
| Posted on Thursday, April 13, 2006 - 10:31 am: |
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quote:Well, I'll try it today and see what happens at 7000RPMs
Power will be gone by 7k rpm, hard rev limit is at 6800rpm. It's a little hard to tell from the tach, but yellow should be 6200-6800rpm. The tach on my '04 XB12R has gray at 6k, yellow above that, and red just before 7k. Your first post made it sound like the power on your bike fell off after 6200rpm, while it should still pull hard all the way up to 6800rpm (through the yellow). |
Xbrad9r
| Posted on Thursday, April 13, 2006 - 11:59 am: |
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i have hit the rev-limiter a couple of times doing fast passes in limited space...i do not lose power until the rev-limiter stops me, it climbs quickly and the rev limiter kicks in to remind me to "shift dummy". |
M1combat
| Posted on Thursday, April 13, 2006 - 12:19 pm: |
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The power increases pretty linearly all the way to the redline on the 12. The spark gets cut at 6800 on a 12, 7500 on a 9. I tend to shift at about 5800. No reason to tear it up just for fun . I'm sure I'll carry it to about 6300 on the track. |
Spike
| Posted on Thursday, April 13, 2006 - 12:22 pm: |
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Just to add to the rev limiter discussion . . . The XB12s have another rev limiter in addition to the hard limiter at 6800rpm. It comes on if the motor is kept over 6200rpm for a few seconds (3?). At first the limiter is a soft limiter and only reduces power, but if held above 6200rpm for longer (5 seconds?) it turns into a hard limiter and drops the motor back to 6200rpm. |
Buellistic
| Posted on Thursday, April 13, 2006 - 03:16 pm: |
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Set the SHIFT LITE to come on at 6800 RPM ... |
Blake
| Posted on Thursday, April 13, 2006 - 03:21 pm: |
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Shea, Good point. A newer tighter engine will fade more at higher revs. Keep in mind too that in higher gears, even 3rd gear, wind resistance become a significant factor thwarting acceleration; it increases with speed squared. |
Chadhargis
| Posted on Thursday, April 13, 2006 - 03:34 pm: |
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When riding my aggressively...I take it to the limiter frequently. That's what it's there for. You aren't damaging anything by doing so. |
Fullpower
| Posted on Thursday, April 13, 2006 - 03:36 pm: |
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atmospheric drag increases in proportion to speed CUBED. |
M1combat
| Posted on Thursday, April 13, 2006 - 03:38 pm: |
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"That's what it's there for. You aren't damaging anything by doing so." You are in the long run. |
Blake
| Posted on Thursday, April 13, 2006 - 04:29 pm: |
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Fullpower, Drag increases with speed squared. The HP required to overcome drag increases with speed cubed. It can make your head hurt pretty bad, I know. Start with the simple equation... power = force*distance/time-interval and since... speed = distance/time-interval then... power = force * speed Recalling that the force is actually drag which increases with speed2 if we double speed (2*speed) we have... power = (2*2*force)*(2*speed) = 8*force*speed and 8 = 2*2*2 Like I said, it can make your head hurt. |