supra5677
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posted April 08, 2010 09:34 AM
I have access to a pretty good fabricator and mechanic. I was considering making the air box smaller. Any suggestions?
   
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KZScott
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posted April 08, 2010 03:16 PM
make the motor bigger to make the air box act smaller
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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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psycho1122
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posted April 10, 2010 05:42 AM
quote:
yes supra but not so good for testing purposes on the dyno.
decided now we have to make one of these manometer things to test all bikes for comparison purposes.
oh dear, never ending
You don't need the "manometer". Just set up a volt meter in parallel to the Intake air pressure / vacuume sensor. Use the chart for the sensor from the ZX12 service manual to define the #s.
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You say PSYCHO like it's a BAD thing!!
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supra5677
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posted April 10, 2010 10:33 AM
I found an article about Ram Air Recovery from Doug M.:
A little clarity on the subjects of ram air and velocity stacks seems to be in order. Vincent, I found your little story about all those hungry people being crammed into that room entertaining, but kind of short on actual physics so I hope you’ll forgive me for supplying a few facts.
The equation that represents ram recovery is expressed (in words, because scientific notation is hard in MSword) as follows: The pressure (in psi) resulting from what we commonly refer to as “ram air” is approximately equal to the air density times the velocity of that air squared, divided by the constant 4311. Now, the velocity is EITHER the velocity of moving air in relation to a stationary object, OR a moving object (like a ZX-12) in relation to stationary air. You’ll notice (I hope) one thing that is obviously missing in the equation, and that is the SIZE of the opening. It’s not there because IT DOESNT MATTER. The only variable is the density of the air (due to barometric pressure or temperature). It doesn’t matter because basic gas laws suggest that pressure per unit of area (psi) in a closed “box” is equal everywhere in that box regardless of the size of the pressure’s “entrance” to the box (think hydraulics). One thing that DOES matter, though is the shape of the inlet to the ram “tube” or duct. Studies (and there are plenty of them) show that a straight edged tube only recovers less than 20% of what is available. Put a small radius on the entrance and that jumps to 85%, put the CORRECT radius on the entrance and it gets very close to 100%. Well assume we’ve done that. So here’s an example:
Standard air has a density is about .076 pounds per cubic foot. Now, let’s ram a 200 mph ZX-12 into it.
.076 X 200 squared = 3040, divided by 4311= .7051 psi. That is .7 psi OVER atmospheric pressure of 14.7 psi, no? Add the .7 to the 14.7 and you get 15.4 psi in the airbox at 200 mph. That is a 5% increase in the density of the air going to the engine, which (since an engine is just a machine that supplies oxygen molecules to be mixed with fuel in a more or less standard ratio and burned to produce power) results in about a 5% increase in power.
By now some of you are hollering, “yeah but what about the air the engine is using OUT of the air box that needs to be made up?” Well true, but that depends on the FLOW not the pressure. Remember that pressure at the entrance to the engine STANDING STILL, NOT RUNNING is 14.7 psi. (standard day). You are only adding to that number. If the opening in the inlet is large enough allow the necessary amount of air to pass through it at wide open throttle-max RPM (stationary) the ram recovery will only increase the density. How much air IS that anyway?
Well, on an 1197cc engine at 11,000 rpm it’s 232 cubic feet per minute (assuming 100% volumetric efficiency). That’s not very much, comparatively speaking. Take a look at the intake on current F-1 car; it needs to handle more than 3 times that much. So what I’m saying is that the air inlet on our bikes is plenty big and probably quite good at ram recovery.
Now, on the subject of velocity stacks, stacks are NOT there to squeeze the air into the injector. They are there to smooth the already pressurized air from the airbox on it’s way into the injector body, and they are there to harness and capture the extra energy in the moving column of air caused by the sonic waves traveling up and down through this column. These waves, which really do travel at the speed of sound, are caused by the sudden starting and stopping of the moving air and the rapid opening and closing of the valves. When the valves open, one pulse starts back “upstream” towards the entrance to the tube (stack). When that pulse reaches the open end, another pulse is generated that starts back down towards the cylinder. These pulses (remember they’re “sonic” waves) are of course, moving much faster than the moving air which is only going about 180 mph. The principle of and reason for varying the length of the stacks is to get these waves “in sync” so that they get to the valves just before they slam shut, thereby increasing the local velocity (and amount) of air molecules that make it into the cylinder. It is easy to understand, then, why different length stacks work better at different RPMs. One length will help up high, possibly at the cost of low end, and vice versa. One particular length is the best compromise for “total area under the curve”. It is therefore very important to have the correct inlet shape AND length (this is of course also the theory of exhaust tuning). Any narrowing of the throat, while being an efficient way to go from a larger diameter to a smaller one does not, as Vincent suggested, “cram” more hungry guys into the room. If you narrow the cross section in a tube flowing a compressible fluid, the local pressure will drop because the speed goes up (think venturi effect) and then if and when the cross section gets larger again the speed drops and the pressure returns to what it was going in. The volume remains the same (damn physics again). This phenomenon is one of the ways we get volumetric efficiencies greater than 100%.
The shape of the inlet of the stack maximizes the flow FROM the airbox or atmosphere into the tube as described above. The radius on the entrance of the stack is very important, but only up to the point that there is no loss. It can’t “add” but it can certainly “subtract” it. Regarding having different lengths on groups of cylinders, what you get is some cylinders working better at one point and others at another. The peaks are “softened”, it spreads power a bit. Historical note: Those of you that have cited the different length stacks on the older Chevy Big Block engines, the lengths are different not for that reason, but because there are two different length inlet ports in the original heads. “Short” ones and “long” ones. The different length stacks just make them all the same from the stack entrance to the inlet valve. (Ever wonder why you never saw staggered stacks on a small block....?)
Doug
based on Doug's Formula at 219 mph (y2k's top speed run) the zx12r should be making .845psi or 58.25 mb of pressure. Y2k only logged 30mb.
At 200 mph 48 millibars and 210 mph 53.56 millibars.
I'm going to purchase the air tech streamlining intake duct then hook up a data logger. I will mount the duct 1.5 inches beyond flush with the fairing. I have a b model might look a little funny but thats ok. I also nee to seal that small hole in the steering head inside the air box.
supra
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supra5677
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posted April 10, 2010 10:45 AM
Question:
How do we know the air inlet pressure sensor is calibrated correctly?I'm going out on a limb but on the zx9r and zx11 there was a tube that balanced the pressure between the air box and the float bowls. Is there a way we can test the calibration on these sensors?
Any input would be appreciated...
supra
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Shane661
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posted April 10, 2010 10:52 AM
 Edited By: Shane661 on 10 Apr 2010 18:55
Do me a favor, Supra. Don't post any results until you log the before and after data at speeds of at least 190 mph.
You started this thread over 2 months ago. So far, no data...do you even have a data logger? If so, please use it.
I'm growing very weary of reading theory. Let's see some practice.
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KZScott
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posted April 10, 2010 11:19 AM
Jim had a 1427, Dougs numbers above were based on stock displacement
____________
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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supra5677
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posted April 10, 2010 01:43 PM
Shane know one is asking you to read my post.
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Shane661
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posted April 10, 2010 01:54 PM
quote:
Shane know one is asking you to read my post.
Nope...but you are asking for input...and you are getting it. 
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supra5677
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Posts: 1279
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posted May 02, 2010 04:40 PM
Please double check my math..
I followed the helmholz resonance formula and measured the following data.
Total area of intake pipes 14.625 inches
air box volume 941.81 cubic inches
length of intake pipe 18.5 inches (roughly)
7.83hz equals 469.8 rpm's..
so 5300* the square root of total area/ air box volume* length of intake pipe
zx12r resonates at 8904 rpm's. Is that right? Did I mix and match cm vs inches.
Thanks,
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psycho1122
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posted May 03, 2010 05:18 AM
I just have to ask you Supra......................
Why are you trying to Re-Figure out what the good 'ol boy's in the white lab coats have already done?!?
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You say PSYCHO like it's a BAD thing!!
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supra5677
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posted May 03, 2010 06:26 AM
This board use to be helpful. Maybe it's the economy.  Anyways
y2kzx12r is going to get me some of his data. He is working on
something similar for the zx14. Those who are math savvy can address
my qyestion.
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psycho1122
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posted May 04, 2010 05:15 AM
Wow Supra! Sarcasim does not answer the question.
Have you read this thread yet?!?
hans test/ doesnt work!!!
Yep! You must have....even on page 8, you had a few posts. Most of your answers are there.
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You say PSYCHO like it's a BAD thing!!
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supra5677
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posted May 04, 2010 09:18 AM
I never had any intention of using the hans snorkel. You proved years ago that it didn't work... I don't understand...
supra
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Shane661
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posted May 04, 2010 09:23 AM
quote:
I never had any intention of using the hans snorkel. You proved years ago that it didn't work... I don't understand...
supra
Have you started logging any data yet?
What is your intended testing methodology?
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supra5677
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posted May 04, 2010 10:57 AM
Psycho and y2kzx12r have already logged data from the ram air pressure sensor in the throttle bodies. They have been nice enough to share it with us. Y2K just sent me an abundance from his top speed runs at loring.
The only issue I see ( I'm taking my time with this ) is in the recovery from what goes into ducts to what actually gets into the throttle bodies. From Y2k's data I'm seeing a 57% loss in pressure from a theoretical 57 millibars to an actual 25 millibars.
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Shane661
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posted May 04, 2010 10:59 AM
Edited By: Shane661 on 4 May 2010 19:01
quote:
Psycho and y2kzx12r have already logged data from the ram air pressure sensor in the throttle bodies. They have been nice enough to share it with us. Y2K just sent me an abundance from his top speed runs at loring.
The only issue I see ( I'm taking my time with this ) is in the recovery from what goes into ducts to what actually gets into the throttle bodies. From Y2k's data I'm seeing a 57% loss in pressure from a theoretical 57 millibars to an actual 25 millibars.
You can't test modifications without logging your own data. Otherwise, the comparisons are meaningless.
Let go of your "theoretical"...and embrace the "practical". Otherwise, you are wasting your time.
Again, what is your intended testing methodology?
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psycho1122
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posted May 05, 2010 04:43 AM
Yes supra, the Hans did not work. However, I did compare it to a STOCK system.
The Data is there.
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You say PSYCHO like it's a BAD thing!!
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supra5677
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posted May 05, 2010 07:10 AM
Agreed I know... By the way what kind of data logger did you use and where can I buy one?
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Y2KZX12R
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posted May 06, 2010 03:14 AM
Actually the data I sent you was from a 3rd baro sensor that I hooked up that had a tube running into the airbox. So its actual air box pressure.
You cant use the MAP sensor for measuring the ramrecovery/air box pressure. Its measuring the manifold pressure and they are very different.
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Y2KZX12R
CompetitionCNC.com
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supra5677
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posted May 06, 2010 07:16 AM
Ok I see.
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supra5677
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Posts: 1279
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posted May 06, 2010 07:27 AM
Compared to the zx9r the zx12'sram air system is not that good.
link:http://www.sportrider.com/tech/146_9508_ram/index.html
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