KZScott
Needs a life
high on speed
Posts: 7235
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posted August 14, 2009 06:18 PM
tire bouncing in burnout wtf?
anyone ever had a tire go from working great to jumping up and down like a jackhammer in a burnout? it felt fine for the run, but the next time i tried it i didnt really get much smoke so i had a rolling burnout for a launch....
switched to my spare tire and problem went away
anyone ever expirience this? oh and my spare tire (diff rim) has less tread than my other one, im not sure if i can last the wknd now  both stock zx12 rims and 190 50 shinkos
oh, turned the 2 step down to 4000 and im getting much more manageable launches, i need to take out a little static for the morning, but the good news is im running my "nitrous" amount of weight on the arms, so as soon as i get back to 9.2s the bottle is going on  got down to a 9.32 @149. earlier in the night i had a not so great launch, but nailed the rest of the run, hit my shift points well, had a great tuck ect, ran 152mph, best NA mph to date, and it was hot and muggy....
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01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
  
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kawasakijockey
Pro
Posts: 1876
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posted August 14, 2009 06:38 PM
My Shinko does that if I run under 18 psi sometimes.
____________
Get on the shortbus boys 'cause its time to get schooled.
2007 ZX-14
1.38 60ft
9.03 @ 149mph
8.95 @153 small shot n2o
8.68 @160mph 5lbs boost
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KZScott
Needs a life
high on speed
Posts: 7235
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posted August 14, 2009 07:04 PM
ive never ran over 11.5... ever :S. last yr, it was 8-9, this yr ive been around 10-11.5 depending on how well the track was prepped. hmm maybe i should try it at 12, it felt fine on the top end
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01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
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kawasakijockey
Pro
Posts: 1876
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posted August 14, 2009 07:09 PM
I usually run it at 22-24 and it has never done there. I would like to know the answer to this myself.
____________
Get on the shortbus boys 'cause its time to get schooled.
2007 ZX-14
1.38 60ft
9.03 @ 149mph
8.95 @153 small shot n2o
8.68 @160mph 5lbs boost
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dubious
Needs a life
Needs more time to ride!
Posts: 8442
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posted August 14, 2009 08:28 PM
tire imbalance if it occurs with new tire, on known rim,
or uneven wear would be my guess, if it gradually occurs
If the tire begins to bounce and you continue to burnout with it bouncing, eventually it wears uneven
____________
natural selection.....
destiny will overcome intervention.
Some are not worthy of the effort.
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CrotchRocket
Moderator
Bracket Racing with Betsy
Posts: 8038
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posted August 14, 2009 09:07 PM
Thats happens when the track is prepped well, your at low air pressure AND when you didnt have the RPMs high enough at the start of the burnout or didnt snap the clutch out for the burnout !!!
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Jason Miller StreetBike Seminars
*****DragRacers do it better, because they dont cut Corners*****
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tcchin
Zone Head
Posts: 867
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posted August 15, 2009 01:00 AM
In addition to the other suggestions, you may want to consider the possibility that your tire spun on the rim and got out of balance. That happens to us occasionally. Really sucks when it happens on the start and you have to run 25 laps like that.
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KZScott
Needs a life
high on speed
Posts: 7235
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posted August 15, 2009 01:39 AM
i checked my rim, i cant find any wheel weights.... it must have had at least one. and yes this tire has moved about 6 inches after being initially mounted. my spare has moved about 3/4 of the way around to making a full spin however...(lower pressure last yr)
im thinking i should go get it balanced at lunch time today? maybe try it again for a TT
thx for the input guys!
(oh and btw, clutch cover didnt come off all last night, lock up is very close)
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
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Shane661
Needs a life
Posts: 11494
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posted August 15, 2009 03:48 AM
 Edited By: Shane661 on 15 Aug 2009 11:49
Imo, balancing is a waste of time on a dragracing wheel. The tire gets huge clumps of rubber all around it, and the rim can spin in the tire on occasion. Unless you plan to balance it after each day at the track, you are probably wasting your time (and if you do it after each track day, you are really wasting your time!).
The "jackhammer" effect was likely due to the tire alternately slipping and then grabbing. That could be related to your technique, or perhaps even the clutch. Sounds like that tire was getting good bite (at least in the burnout box).
Shane
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tcchin
Zone Head
Posts: 867
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posted August 15, 2009 11:09 AM
Do you use duct tape over your tire weights? That's a requirement in roadracing. We've never lost a weight that was taped in place.
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KZScott
Needs a life
high on speed
Posts: 7235
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posted August 16, 2009 06:02 PM
no tape
CR was right on the money, it was extra rubber on the pad and a bit to do with my style, lots of guys told me that it happened. we had an all bike wknd, so instead of the 15 or so at a points meet, there was closer to 80. a few guys that have been doing it longer than me said to not even bother balancing the tire, we even changed one guys there to a new shinko from a race take off
i switched back to the other tire and rim and it was fine the rest of the day. i hit it with a more agressive burnout, and if it started hopping i rolled ahead a bit and it was fine. for no cars there, traction was actually really good, i ran 11 psi with no issues, and the tire didnt spin in the rim more than an in all day. next points meet ill try going higher
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
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chavcat
Zone Head
Posts: 524
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posted August 16, 2009 06:24 PM
Scott - How did the bike run?
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KZScott
Needs a life
high on speed
Posts: 7235
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posted August 16, 2009 06:29 PM
see new thread
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
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NOX
Needs a job
PMRA / TMRC Super Street 4022
Posts: 3745
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posted August 16, 2009 06:36 PM
get the rpms up.........
when you are geared low, it happens, thats why i do second gear burnouts.
____________
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