Spoon snorkel restrictive?
03-29-2006 | 04:15 PM
#31
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From: Scatterbrainia
Originally Posted by dolebludger,Mar 29 2006, 04:59 PM
IMO, it takes a larger "air catching" device than the horn on the spoon to do this, and mine is built much larger. So I criticize the Spoon not only for the "pinch" but also for having too small an "intake horn" to provide ram air.
03-29-2006 | 06:53 PM
#32
Joined: Nov 2002
Posts: 2,060
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From: Durango, Colorado
This post above sums up my personal opinion of the Spoon (and its copies) rather well. While the Spoon seems to provide a source of pasive cool air (i.e., that sucked in by the intake), the amount of cool air that can be so obtained is limited by "the pinch". And the combination of "the pinch" and rather small intake horn area prevent it from having any ram air value.
Thanks,
Richard
Thanks,
Richard
03-29-2006 | 07:45 PM
#33
Joined: Sep 2003
Posts: 10,301
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From: New Jersey
Originally Posted by dolebludger,Mar 29 2006, 12:48 PM
I must respectfully disagree with the concept that the "pinch" in the snorkel matters not. Here's a "fluid dynamics" experiement you car try that shows what I mean. Put a ballcock shut off valve on a garden hose, and turn on the spigot full. Observe how mcuh water is flowing (and its pressure) with the ballcock valve in the full on position. Now fill a container with the water, and time how long it took to fill that container. Now, turn the ballcock valve to the "half on, half off" position and fill the same container with the water, and time how long it took. Here, the water pressure from the spigot remains the same. But when a "pinch" is added to the flow by turning the ballcock valve to the "half" position, the rate of water flow is significantly lessened, and it takes longer to fill the given container.
I also respectfully disagree with the statements that seemingly say that a ram air device on an automobile won't work. I will agree that it will not produce any great increase in hp. and/or torque, but it will produce a little. As I recall, the "ram air" option on the mid '90s Trans Ams was good for about 10 hp. And many Grand Prix cars have ram air scoops mounted on them. And the intakes are made as large as possible, and the air paths have no "pinches" for the reasons I mention in the paragraph above.
Thanks,
Richard
I also respectfully disagree with the statements that seemingly say that a ram air device on an automobile won't work. I will agree that it will not produce any great increase in hp. and/or torque, but it will produce a little. As I recall, the "ram air" option on the mid '90s Trans Ams was good for about 10 hp. And many Grand Prix cars have ram air scoops mounted on them. And the intakes are made as large as possible, and the air paths have no "pinches" for the reasons I mention in the paragraph above.
Thanks,
Richard
In your example you are pretty much putting up a wall to block the water; it is not a "gradual" change in area. In that case it will be less. So your example is not completly relivent.
To go back on to the subject of the spoon intake. Even if we do through in this restriction and whatever else we are debating about, I said in my first post that it is mostly negligable because we are talking about 1 hp...maybe 2? There is hardly any difference.
Its restrictive yes. Does it make much / if any of a difference...no.
You can go out a buy a 3 grand intake and it'll gain you maybe 5hp. With that being said, don't expect more then 1 or 2 out of a snorkel
03-30-2006 | 06:51 AM
#35
Joined: Nov 2002
Posts: 2,060
Likes: 1
From: Durango, Colorado
Spec_Ops2087:
OK, if my suggestion for as test using a ballcock valve on a garden hose wouldn't be comparable to the pinch in the Spoon, try the same experiment with an unrestricted hose and one with one of those "driveway cleaning fittings" on it. Those fittings gradually reduce the diameter of the water flow, instead of "putting up a wall" like a ballcock. You'll still find that it takes much longer to fill that container with the restrictive fitting than with an open garden hose.
I'm not saying the Spoon is worthless, as anything that can supply any air other than the hot air under the hood (as the stock set up does) will be of benefit. And I'm certainly not saying that anybody should spend thousands on an intake system, as we agree the gains aren't worth it. What I am saying is that an AUT or Garage Defend radiator cooling plate and CA has significantly less "pinch" than the Spoon, at a lower cost, with more added power to boot.
Thanks,
Richard
OK, if my suggestion for as test using a ballcock valve on a garden hose wouldn't be comparable to the pinch in the Spoon, try the same experiment with an unrestricted hose and one with one of those "driveway cleaning fittings" on it. Those fittings gradually reduce the diameter of the water flow, instead of "putting up a wall" like a ballcock. You'll still find that it takes much longer to fill that container with the restrictive fitting than with an open garden hose.
I'm not saying the Spoon is worthless, as anything that can supply any air other than the hot air under the hood (as the stock set up does) will be of benefit. And I'm certainly not saying that anybody should spend thousands on an intake system, as we agree the gains aren't worth it. What I am saying is that an AUT or Garage Defend radiator cooling plate and CA has significantly less "pinch" than the Spoon, at a lower cost, with more added power to boot.
Thanks,
Richard
04-06-2006 | 12:01 PM
#36
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From: Vancouver
Originally Posted by slimjim8201,Mar 29 2006, 04:59 AM
Here is the confusion. Lets compare two snorkels. One with a tight constriction, and one without, both generally shaped like the Spoon. The only thing we can hold constant is the pressure drop across the system. We know that the engine is going to produce some sort of negative pressure that will propagate back through the intake system to the exit of the snorkel. We'll assume that the pressure on the inlet to the snorkel is more or less atmospheric.
Now, we have two similar pipe systems with the same delta P, but one has a slightly more restrictive constriction. They will NOT provide the same flow rate. The flow rate will be constant throughout the length of each individual snorkel, but the less restrictive one will have the higher flowrate of the two.
Now, we have two similar pipe systems with the same delta P, but one has a slightly more restrictive constriction. They will NOT provide the same flow rate. The flow rate will be constant throughout the length of each individual snorkel, but the less restrictive one will have the higher flowrate of the two.
Say the car is travelling at 60mph. The air going into the inlet of both snorkels will be of the same amount and force, regardless of the pinch at the top of one, correct?
Therefore, if the above is true (which I am assuming and not sure), then the load is the same. If the load is the same, the same amount of air is entering the inlet for both cases. Hence, the same amount of air will exit at the same rate for both cases as well.
I know this is not true for many cases in real life, but I cannot seem to find the fluid mechanics theory behind it.
For example, take the two snorkels and use a leaf blower to blow at the inlet. The load is the same, wouldn't the outlet be the same given continuity theorem?
02-28-2007 | 12:15 AM
#37
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i hate to revive this, but reading this post is funny. assumption is the mother of all **** ups. most people that post are making assumptions and are really full of non-sense.
im glad that someone knows fluids. the pinch increases the velocity of the air flowing through it. for those that cant speak math, grab a hose and turn it on, put your favorite finger on the end and watch the water spray out faster and farther. the same quantity of fluid is being let out of the hose, except at a higher velocity with your favorite finger creating the difference. hence the spoon snorkel design. dumbasses remind me of the people who drive the pickups with the tailgate down because they think it reduces drag.
im glad that someone knows fluids. the pinch increases the velocity of the air flowing through it. for those that cant speak math, grab a hose and turn it on, put your favorite finger on the end and watch the water spray out faster and farther. the same quantity of fluid is being let out of the hose, except at a higher velocity with your favorite finger creating the difference. hence the spoon snorkel design. dumbasses remind me of the people who drive the pickups with the tailgate down because they think it reduces drag.
02-28-2007 | 12:50 AM
#38
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Originally Posted by dolebludger,Mar 29 2006, 09:48 AM
I must respectfully disagree with the concept that the "pinch" in the snorkel matters not. Here's a "fluid dynamics" experiement you car try that shows what I mean. Put a ballcock shut off valve on a garden hose, and turn on the spigot full. Observe how mcuh water is flowing (and its pressure) with the ballcock valve in the full on position. Now fill a container with the water, and time how long it took to fill that container. Now, turn the ballcock valve to the "half on, half off" position and fill the same container with the water, and time how long it took. Here, the water pressure from the spigot remains the same. But when a "pinch" is added to the flow by turning the ballcock valve to the "half" position, the rate of water flow is significantly lessened, and it takes longer to fill the given container.
I also respectfully disagree with the statements that seemingly say that a ram air device on an automobile won't work. I will agree that it will not produce any great increase in hp. and/or torque, but it will produce a little. As I recall, the "ram air" option on the mid '90s Trans Ams was good for about 10 hp. And many Grand Prix cars have ram air scoops mounted on them. And the intakes are made as large as possible, and the air paths have no "pinches" for the reasons I mention in the paragraph above.
Thanks,
Richard
I also respectfully disagree with the statements that seemingly say that a ram air device on an automobile won't work. I will agree that it will not produce any great increase in hp. and/or torque, but it will produce a little. As I recall, the "ram air" option on the mid '90s Trans Ams was good for about 10 hp. And many Grand Prix cars have ram air scoops mounted on them. And the intakes are made as large as possible, and the air paths have no "pinches" for the reasons I mention in the paragraph above.
Thanks,
Richard
02-28-2007 | 05:25 AM
#39
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Joined: Nov 2003
Posts: 315
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From: New Jersey
Okay;
1) I'm not worried about transition behavior. Air flow through the snorkel may well be laminar. Does anybody have the duct's major and minor dimensions? I can do a quick calculation on Reynolds number to at least get a sense. We could also calculate the hydraulic diameter.
2) Air compressibility is not going to be a factor in this system (until you get into the cylinder and the valves close). I can't imagine the velocity is anywhere near Mach.
3) All this being said, I'd be surprised to learn that this shape did not induce higher pressure loss at a given flow rate. There's a lot of wetted surface area compared with the cross-section, and the channel is so narrow, the whole thing is going to be dominated by boundary layer effects (which is bad). And obviously, if the cross-section is smaller, the mean stream velocity will be higher, which of course increases flow losses.
1) I'm not worried about transition behavior. Air flow through the snorkel may well be laminar. Does anybody have the duct's major and minor dimensions? I can do a quick calculation on Reynolds number to at least get a sense. We could also calculate the hydraulic diameter.
2) Air compressibility is not going to be a factor in this system (until you get into the cylinder and the valves close). I can't imagine the velocity is anywhere near Mach.
3) All this being said, I'd be surprised to learn that this shape did not induce higher pressure loss at a given flow rate. There's a lot of wetted surface area compared with the cross-section, and the channel is so narrow, the whole thing is going to be dominated by boundary layer effects (which is bad). And obviously, if the cross-section is smaller, the mean stream velocity will be higher, which of course increases flow losses.
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