KZScott
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high on speed
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posted May 11, 2010 06:32 PM
ways to detect detonation
I was wondering what the best way to hear this on a bike would be? I was having a chat with my tig guy (pretty serious into the ricer car scene type of guy) and he was saying how a tuner he knows uses these tubes that are connected to ear muffs and the other end is bolted to the motor with copper tubing? he said its really goofy looking but a really cheap/effective way to hear a motor knocking. I was wondering if this was even possible to hear on a bike at speed? or if there is anything to watch in a log file(what?) that would show signs of detonation. theres so many opinions out there on timing its hard to guess as to what may be safe, and what is too much. I want to know if im flirting with disaster either NA or on spray
will AFR show any hints or would I need some sort of 5 gas analyzer?
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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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ZRXDean
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Posts: 2225
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posted May 12, 2010 09:07 AM
I've heard of electronic boxes that 'listen' for detonation with contact sensors on the block, and retard timing accordingly. I think it's not uncommon on modern car ECUs.
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smokeysevin
Novice Class
ZX12r-STX15f hybrid motor
Posts: 82
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posted May 12, 2010 10:34 AM
This is just a theory but coming from a background in Jetskis, you may be able to take the knock sensor setup from a seadoo RXTX and wire it up to the engine on your bike, then just set it so it lights up when you get DETO, the only problem with that would be finding out how the sensors work.
I come from a kawasaki background so seadoo stuff is kind of unknown to me
Sean
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1498 cc
69.2mm stroke
83mm bore
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dubious
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posted May 18, 2010 07:10 PM
bombardier has a sweet little sensor just as smokeysevin says. they use the same one on their sleds
about the size of 5 nickels stacked, picking up resonance off the head
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natural selection.....
destiny will overcome intervention.
Some are not worthy of the effort.
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Y2KZX12R
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CompetitionCNC.com
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posted May 19, 2010 03:24 AM
Scott, the sensor off of the zx-12 powered jet ski would be a good place to start.
The "knock" sensors are piezo sensors with a resonant frequency tuned to a particular engines resonant frequency. So how closely this sensor frequency is matched to the engines resonant frequency during detonation is very important.
I suppose you could detect the engines resonant frequency with some sort of sensor and striking the fully assembled engine with a hammer etc.
This is how we used to test to see if a knock sensor was working back in the 1980's on the early engines with knock sensors. We would have a timing light on the engine watching the advance at 3000 rpms or so and tap on the side of the block with a two foot 1/2" drive extension or something. The timing would retard for a moment and then return to normal.
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Y2KZX12R
CompetitionCNC.com
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dubious
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posted May 19, 2010 10:41 AM
cool info Jim,
I never knew the jet ski had one.
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natural selection.....
destiny will overcome intervention.
Some are not worthy of the effort.
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salsa1
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posted May 20, 2010 11:14 AM
Finding a hole through one of your pistons is a dead giveaway Scott......
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Salsa1
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KZScott
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posted May 20, 2010 07:04 PM
its possible to have detonation without holing a piston instantly.... the idea is to find out in advance to prevent problems.
Thanks for the info Jim, as allways its greatly appreciated 
so how do I get the knock sensor to retard timing? have it activate an EFIR or similar product?
____________
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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salsa1
Needs a life
Posts: 5971
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posted May 21, 2010 01:01 PM
Yes I would not wait for extreem pitting or a piston hole to occur as an indicator Scott.....was just kidding ya scott....
can google it and see what else is available for ideas to be more serious...
Take no chances as best possible..good luck... 
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Salsa1
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Y2KZX12R
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CompetitionCNC.com
Posts: 3762
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posted May 22, 2010 02:46 AM
 Edited By: Y2KZX12R on 22 May 2010 10:49
Scott, seeing detonation from a sensor signal is the easy part. Using that signal to retard the timing is the hard part.
There may be some kind of electronic gizmo that may work....??
engines with knock sensors have the provision built in... adding it in on a zx12r..... i have no idea short of using a Motec or some other aftermarket ECU.
Mild detonation is quite common in race engines. Detonation and pre-ignition are very different. Detonation on a scale of 1 to 10 isn't damaging to the engine until you get to, well lets just say a 4 or so. You can run an engine in mild detonation say a 1 or 2 and never know it or see any engine issues. But if an engine runs with mild detonation for a long time at red line like at Bonneville then it has an acumulative effect the wiping of the protective boundary layer away each fireing and the parts, mainly the piston, heat soak and the detonation escalates until pre ignition sets in. Once pre ignition sets in then the engine can be instantly destroyed in seconds, actually less than seconds.
If the piston temperature gets over about 375 degrees the aluminum piston becomes annealed and softens up. The heat treatment is gone along with its strength. Then the crazy pressure spikes from an engine running in pre ignition are enough to push a hole in the piston like it was made of soft clay. That's why a piston with a hole in it from severe detonation or pre ignition doesn't break and have sharp edges where the hole is at the center of the piston where the temps are the hottest. It looks like a clay piston and someone pushed there finger threw it.
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Y2KZX12R
CompetitionCNC.com
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smokeysevin
Novice Class
ZX12r-STX15f hybrid motor
Posts: 82
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posted May 22, 2010 01:23 PM
the Kawasaki jet skis dont use knock sensors, the first batch of stx12f jet skis (2003 ninja derived motors) had a recall on alot of them because the ecus ran too much timing and detonated the motors.
That is some very interesting information on why the pistons look the way they do, I never knew that
Sean
____________
1498 cc
69.2mm stroke
83mm bore
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