RICH CRAFT 1
Zone Head
Posts: 681
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posted December 04, 2010 12:04 PM
The ram air seems to work pretty good for me. Ken
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Red 06 ZX14 RR
  
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Shane661
Needs a life
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posted December 04, 2010 12:05 PM
 Edited By: Shane661 on 4 Dec 2010 20:08
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Y2KZX12R
Needs a job
CompetitionCNC.com
Posts: 3762
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posted December 05, 2010 07:54 AM
The zx14 has a lot of spill over at the inlet at LSR speeds.
Basically the inlet frontal area is too big for LSR but is a benefit in drag racing.
Ideally we need a variable frontal area inlet with a variable volume duct to maximize pressure recovery at all speeds. The goal is to match the engine consumption to the column of air entering the inlet. rpm and the speed of the bike are constantly changing.
You could imagine the costs and hardware involved with that so they have to compromise on the design and pick a speed range that they want to optimize the system for.
Thus the high inlet spillover on the zx14 at speeds of 200+ mph.
You actually want the inlet to get smaller as speed increases so you can minimize the spill over and retain the energy (velocity) of the air stream as it enters the duct so you can slow the air down and exchange the energy (velocity) of the incoming air to pressure.
Think of a 2" diameter round cookie cutter going threw the air at 100 mph. The volume of air going threw the cookie cutter (duct) is 100% of the volume of the frontal area x the speed.
Now say there is an engine running at 10,000 rpm and is consuming all of that volume of air going threw the cookie cutter at 100 mph. Now increase the speed of the cookie cutter going threw the air to 200 mph, and you have now doubled the volume of air in that wants to go threw the duct but the engine is still using the same volume of air at 10,000 rpm. This causes spill over of 50%. Its like setting a full glass of water on the floor and pouring more water into the glass. It just spills over. This additional volume doesn't contribute to pressure recovery because it cant enter the duct and have its velocity slowed and its kennetic energy converted back to pressure.
This stuff is very complex. Luckily I have a friend that helps me with this stuff.
We are working on a proper duct system for land speed racing. He is an aerodynamicist and worked for Northrop on the B2's engine ducts among other stuff.
I'm hoping to have a working model for the zx14 by spring.
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Y2KZX12R
CompetitionCNC.com
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Earthbound Missile
Novice Class
08' Silver ZX14
Posts: 47
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posted December 05, 2010 09:35 AM
wow good stuff!
In jet aircraft like the F-14 we used what we called mach boards in the intake to give us this "restriction"
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Earthbound Missile
Novice Class
08' Silver ZX14
Posts: 47
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posted December 05, 2010 09:36 AM
wow good stuff!
In jet aircraft like the F-14 we used what we called mach boards in the intake to give us this "restriction"
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RICH CRAFT 1
Zone Head
Posts: 681
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posted December 06, 2010 10:00 AM
quote:
The zx14 has a lot of spill over at the inlet at LSR speeds.
Basically the inlet frontal area is too big for LSR but is a benefit in drag racing.
Ideally we need a variable frontal area inlet with a variable volume duct to maximize pressure recovery at all speeds. The goal is to match the engine consumption to the column of air entering the inlet. rpm and the speed of the bike are constantly changing.
You could imagine the costs and hardware involved with that so they have to compromise on the design and pick a speed range that they want to optimize the system for.
Thus the high inlet spillover on the zx14 at speeds of 200+ mph.
You actually want the inlet to get smaller as speed increases so you can minimize the spill over and retain the energy (velocity) of the air stream as it enters the duct so you can slow the air down and exchange the energy (velocity) of the incoming air to pressure.
Think of a 2" diameter round cookie cutter going threw the air at 100 mph. The volume of air going threw the cookie cutter (duct) is 100% of the volume of the frontal area x the speed.
Now say there is an engine running at 10,000 rpm and is consuming all of that volume of air going threw the cookie cutter at 100 mph. Now increase the speed of the cookie cutter going threw the air to 200 mph, and you have now doubled the volume of air in that wants to go threw the duct but the engine is still using the same volume of air at 10,000 rpm. This causes spill over of 50%. Its like setting a full glass of water on the floor and pouring more water into the glass. It just spills over. This additional volume doesn't contribute to pressure recovery because it cant enter the duct and have its velocity slowed and its kennetic energy converted back to pressure.
This stuff is very complex. Luckily I have a friend that helps me with this stuff.
We are working on a proper duct system for land speed racing. He is an aerodynamicist and worked for Northrop on the B2's engine ducts among other stuff.
I'm hoping to have a working model for the zx14 by spring.
Jim, I am trying to understand the whole spillover thing. The first thing that comes to mind is a airspeed speedometers for a airplanes they have a small tub usually out on the wing. the faster the plan goes the more air is rammed down the tub making the pressure in the line greater making the needle move higher. If more pressure is what we're looking for ? that sounds like a good thing. But here's what could be happening? The nose on the 14 is in a 45° angle? Approximately. The air moving across the front in at 200mph could be causing a stifling effect? Somewhat like a paint gun were the air moves across a tub that goes down into the bottom of the paint can and pulls the paint out. The air going across the front in at some point could actually be pulling air out of the ram air instead of put it in. I have seen some attempts at this where a guy used a piece of plexiglass and mounted it to the top of the ram air inlet that stuck out about 2 inches trying to trap more air into the ram air instead of it passing over. I guess the real question is at what speed does this start happening? Shane posted that it didn't make anymore pressure after 100 mph?. But I know the ram air is working at higher speeds because my air fuel ratio (WEGO 3) goes from 12.8 at the 3.30 @ 96 mph to 13.00 @150mph at the quarter-mile the only explanation for that is more air pressure at 150 mph at the end of the quarter compared to the 96mph at the 3.30 make the motor Lehner. Ken
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Red 06 ZX14 RR
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Shane661
Needs a life
Posts: 11494
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posted December 06, 2010 10:05 AM
Edited By: Shane661 on 6 Dec 2010 18:15
100 mph was a rough estimate on my part, based on the rpm and logs that I was provided. Rich, by comparison my 12R will go from around 12.4-5:1 to around 13:1 from 3rd through 5th gear. (around 175 mph).
There are a few other factors at play, but you get the idea. I do not know all of the science behind it, but I know that the 14 ram air leaves a lot to be desired for maximum hp at top speed. 
Shane
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mathews
Expert Class
Posts: 425
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posted December 06, 2010 10:33 AM
quote:
quote:
The zx14 has a lot of spill over at the inlet at LSR speeds.
Basically the inlet frontal area is too big for LSR but is a benefit in drag racing.
Ideally we need a variable frontal area inlet with a variable volume duct to maximize pressure recovery at all speeds. The goal is to match the engine consumption to the column of air entering the inlet. rpm and the speed of the bike are constantly changing.
You could imagine the costs and hardware involved with that so they have to compromise on the design and pick a speed range that they want to optimize the system for.
Thus the high inlet spillover on the zx14 at speeds of 200+ mph.
You actually want the inlet to get smaller as speed increases so you can minimize the spill over and retain the energy (velocity) of the air stream as it enters the duct so you can slow the air down and exchange the energy (velocity) of the incoming air to pressure.
Think of a 2" diameter round cookie cutter going threw the air at 100 mph. The volume of air going threw the cookie cutter (duct) is 100% of the volume of the frontal area x the speed.
Now say there is an engine running at 10,000 rpm and is consuming all of that volume of air going threw the cookie cutter at 100 mph. Now increase the speed of the cookie cutter going threw the air to 200 mph, and you have now doubled the volume of air in that wants to go threw the duct but the engine is still using the same volume of air at 10,000 rpm. This causes spill over of 50%. Its like setting a full glass of water on the floor and pouring more water into the glass. It just spills over. This additional volume doesn't contribute to pressure recovery because it cant enter the duct and have its velocity slowed and its kennetic energy converted back to pressure.
This stuff is very complex. Luckily I have a friend that helps me with this stuff.
We are working on a proper duct system for land speed racing. He is an aerodynamicist and worked for Northrop on the B2's engine ducts among other stuff.
I'm hoping to have a working model for the zx14 by spring.
Jim, I am trying to understand the whole spillover thing. The first thing that comes to mind is a airspeed speedometers for a airplanes they have a small tub usually out on the wing. the faster the plan goes the more air is rammed down the tub making the pressure in the line greater making the needle move higher. If more pressure is what we're looking for ? that sounds like a good thing. But here's what could be happening? The nose on the 14 is in a 45° angle? Approximately. The air moving across the front in at 200mph could be causing a stifling effect? Somewhat like a paint gun were the air moves across a tub that goes down into the bottom of the paint can and pulls the paint out. The air going across the front in at some point could actually be pulling air out of the ram air instead of put it in. I have seen some attempts at this where a guy used a piece of plexiglass and mounted it to the top of the ram air inlet that stuck out about 2 inches trying to trap more air into the ram air instead of it passing over. I guess the real question is at what speed does this start happening? Shane posted that it didn't make anymore pressure after 100 mph?. But I know the ram air is working at higher speeds because my air fuel ratio (WEGO 3) goes from 12.8 at the 3.30 @ 96 mph to 13.00 @150mph at the quarter-mile the only explanation for that is more air pressure at 150 mph at the end of the quarter compared to the 96mph at the 3.30 make the motor Lehner. Ken
Wouldnt more load on the motor raise the AFR?
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RICH CRAFT 1
Zone Head
Posts: 681
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posted December 06, 2010 11:28 AM
Wouldnt more load on the motor raise the AFR?
I would think it would lower the afr if the motor can't pull the load it will not burn all the fuel making the motor richer. If I leave at 8000 RPMs and the motor goes to 9000 as i let out on the clutch the AFR's will drop to 11.2 under the strain and then come back to normal as soon as the motor reaches 10.800 or 2 gearshift. If your afr numbers are high the motor is asking for more fuel.
Ken
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Red 06 ZX14 RR
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Shane661
Needs a life
Posts: 11494
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posted December 06, 2010 11:31 AM
Edited By: Shane661 on 6 Dec 2010 19:35
As the motor get's hotter, cylinder sealing could increase....for top speed stuff, just a thought.
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mathews
Expert Class
Posts: 425
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posted December 06, 2010 11:47 AM
But dont most motors use more fuel under a bigger load?
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Shane661
Needs a life
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posted December 06, 2010 12:07 PM
And why is that??
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mathews
Expert Class
Posts: 425
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posted December 06, 2010 12:11 PM
Hey,I am just trying to learn
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RICH CRAFT 1
Zone Head
Posts: 681
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posted December 06, 2010 12:12 PM
quote:
But dont most motors use more fuel under a bigger load?
if the throttle is wide-open and the map is fixed the motor will either burn the fuel or it won't barn it. If it doesn't burn all the fuel it will leave you with a low air fuel ratio. The motor is somewhat like a propane camping lantern. You turn the fuel on and light it then you turn the knob until it burns the brightest. When you map a bike that's what you are shooting for the brightest spot. Ken
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Red 06 ZX14 RR
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kawa74
Expert Class
Posts: 226
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posted December 06, 2010 01:38 PM
To quote ; Kawasaki Marketing." Ram Air increases Airbox Efficiency"
Guys, if your air/fuel ratio goes leaner the FASTER you go, doesn't that mean you are getting more air thru the engine?? the FASTER the bike goes the more efficent the AIR INTAKE becomes. Maybe Kawa knows areodynamics. Just looking at a different angle
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"I have never met a man so Ignorant that I coun't Learn from him"..."Galileo"
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Shane661
Needs a life
Posts: 11494
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posted December 06, 2010 04:16 PM
quote:
Hey,I am just trying to learn
Me too. 
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kawa74
Expert Class
Posts: 226
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posted December 07, 2010 02:27 PM
What is a engine?? It is a pump, it " SUCKS" in air and fuel and burns the mixture creating heat [ POWER ] and waste [ EXHAUST ].
A few numbers to ponder over, these are straight out of SUPERFLOW MANUEL.
A perfect 1 inch hole flows 146 cfm
So a 44 tb is 1.73in x 146 = 251 cfm subtract for butterfly about 5% =240 cfm
44 tb = 1.73 in = 2.35 sq in Cross Sectional Area, or CSA = " 290 MPH "
Smallist CSA is under Valve : max throat is 90% of Valve D
2 x 32mm Valves with 90% throat fiow 227 cfm
2 x 32mm @ 90% have CSA of 2 sq in = "340 mph "
290mph + 340mph = 630 / 2 = " 315 MPH " AVG INTAKE VELOCITY sucking on air intake
This for a zx-14, 3.30 bore, 2.4 stroke @ 10800rpm . If you go up in RPM"s the velocity goes up, if you go up in STROKE the velocity goes up !!
10800 = 315 mph avg intake velocity
10000 = 290
9000 = 262
8000 = 233
7000 = 221
A 14 with 17 / 40 gears runs 200mph @ 10315 rpm
Pretty hard to Ram 200 mph Air @ 10315 into something SUCKING at 300mph !!
As far as I can figure no piston engine can RAM AIR into a intake track !! I could be wrong , but done calculation on 250cc to 932in Motors. P. S. been flowing heads for 33 yrs.
Nowere does Kawasaki says Ram Air rams,, it says Ram Air " increases air box efficiecny"
I believe Ram Air is a marketing gimic, but you can always make improvements, check out Pro Stock , Formula 1 scoops, D shape with round blended edges.
Food for thought,
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"I have never met a man so Ignorant that I coun't Learn from him"..."Galileo"
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Shane661
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posted December 07, 2010 03:10 PM
With a good ram air system, the airbox is pressurized above ambient. This is fact, and has been logged extensively.
Shane
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Lucky14
Pro
Posts: 1439
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posted December 07, 2010 03:18 PM
quote:
With a good ram air system, the airbox is pressurized above ambient. This is fact, and has been logged extensively.
Shane
Specifics?
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You only need two tools: WD-40 and Duct Tape.
If it doesn't move and should, use the WD-40.
If it shouldn't move and does, use the duct tape.
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Shane661
Needs a life
Posts: 11494
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posted December 07, 2010 03:24 PM
quote:
quote:
With a good ram air system, the airbox is pressurized above ambient. This is fact, and has been logged extensively.
Shane
Specifics?
As stated.
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Shane661
Needs a life
Posts: 11494
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posted December 07, 2010 04:18 PM
Some general reading:
http://www.sportrider.com/tech/146_9508_ram/index.html
Honestly, the fact that oem ram air systems can provide airbox pressurization above ambient is not even open for debate at this point.
Shane
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smokinZX14
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posted December 07, 2010 05:21 PM
Edited By: smokinZX14 on 8 Dec 2010 01:21
.
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Smokin Performance Cycles..
Tampa Bay , FL .. Brocks Performance Dealer ..
Gen 2 ZX14R Best ET 8.43 , Best MPH 164.95
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Lucky14
Pro
Posts: 1439
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posted December 07, 2010 05:55 PM
quote:
Honestly, the fact that oem ram air systems can provide airbox pressurization above ambient is not even open for debate at this point.
Shane
So why wouldn't this be your first mod?
BTW, is this the RIGHT WAY or the WRONGWAY to do the mod?
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You only need two tools: WD-40 and Duct Tape.
If it doesn't move and should, use the WD-40.
If it shouldn't move and does, use the duct tape.
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Shane661
Needs a life
Posts: 11494
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posted December 07, 2010 05:57 PM
Edited By: Shane661 on 8 Dec 2010 01:59
quote:
So why wouldn't this be your first mod?
BTW, is this the RIGHT WAY or the WRONGWAY to do the mod?
Do you know what is involved with re-engineering and fitting a new ram air system?
For the dragstrip, it is not worth it...speeds are too low.
As for Roy's system, well it probably didn't gain too much over stock....based on what I can see. Maybe he will have something different to say?
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