Spoon snorkel restrictive?
03-28-2006, 01:23 PM
#11
Jakup:
I had the same concerns about the Spoon snorkel (and its copies). So instead, I bought an AUT radiator cooling plate and CAI (check it out on Sponsor Group Buys), and did some other mods including sealing up the throat of the CAI to the airbox, gutting same, and installing an airscoop between the bottom part of the grill and the throat of the CAI. The scoop has an area of about 60 sq in. Much larger than the "horn on the Spoon. At some combinations of speed and RPM, I have proof that it puts the air box into compression. No, it's not a "supercharger" but it does furnish plenty of air from the outside that is as cool as possible. Email me at richhruth@aol.com, and I'll send you a "zipped document with a write-up and pics.
Thanks,
Richard
I had the same concerns about the Spoon snorkel (and its copies). So instead, I bought an AUT radiator cooling plate and CAI (check it out on Sponsor Group Buys), and did some other mods including sealing up the throat of the CAI to the airbox, gutting same, and installing an airscoop between the bottom part of the grill and the throat of the CAI. The scoop has an area of about 60 sq in. Much larger than the "horn on the Spoon. At some combinations of speed and RPM, I have proof that it puts the air box into compression. No, it's not a "supercharger" but it does furnish plenty of air from the outside that is as cool as possible. Email me at richhruth@aol.com, and I'll send you a "zipped document with a write-up and pics.
Thanks,
Richard
03-28-2006, 02:22 PM
#12
Jakup:
Or here's a link to all this info on this board
https://www.s2ki.com/forums/index.php?showtopic=365455
Thanks,
Richard
Or here's a link to all this info on this board
https://www.s2ki.com/forums/index.php?showtopic=365455
Thanks,
Richard
03-28-2006, 05:04 PM
#14
I figure I will through out some information as to if that "kink" is restrictive.
The truth is, it is not restrictive if we are considering air an ideal fluid (which in this case because air is not being compressed, there is not much viscosity, and assuming the flow lines do not cross -- I have no real way of finding that out so we have to assume it as true).
A very common law is that the fluid rate is always constant for an ideal (edited)fluid. That being said, the air rate of the snorkel at the bottom will be the same air rate at the top even after the kink.
A1*v1=A2*v2 -- this shows what will happen with the kink however. If you work it out it just means that because of the kink the air will flow faster at the top after the kink because the area is smaller. And then going back to what I first said, despite it flowing faster the air rate will still be the same.
So is it restrictive...no (and if it is, it is negligable)
The truth is, it is not restrictive if we are considering air an ideal fluid (which in this case because air is not being compressed, there is not much viscosity, and assuming the flow lines do not cross -- I have no real way of finding that out so we have to assume it as true).
A very common law is that the fluid rate is always constant for an ideal (edited)fluid. That being said, the air rate of the snorkel at the bottom will be the same air rate at the top even after the kink.
A1*v1=A2*v2 -- this shows what will happen with the kink however. If you work it out it just means that because of the kink the air will flow faster at the top after the kink because the area is smaller. And then going back to what I first said, despite it flowing faster the air rate will still be the same.
So is it restrictive...no (and if it is, it is negligable)
03-28-2006, 06:12 PM
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i installed a spoon snorkel a month or so back but left the L shaped guide(the piece connected to the bottomside of the airbox lid) on. i bought it used so no instructions were given. was i suppose to of removed the L shaped guide as well? if so, what is holding the guide in place?
i dont mean to hijack a thread but i was reading above saw 2 posts that mentioned doing so. thanks
i dont mean to hijack a thread but i was reading above saw 2 posts that mentioned doing so. thanks
03-28-2006, 07:14 PM
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Originally Posted by Spec_Ops2087,Mar 28 2006, 09:04 PM
The truth is, it is not restrictive if we are considering air an ideal fluid (which in this case because air is not being compressed, there is not much viscosity, and assuming the flow lines do not cross -- I have no real way of finding that out so we have to assume it as true).
A very common law is that the fluid rate is always constant for an ideal gas. That being said, the air rate of the snorkel at the bottom will be the same air rate at the top even after the kink.
A1*v1=A2*v2 -- this shows what will happen with the kink however. If you work it out it just means that because of the kink the air will flow faster at the top after the kink because the area is smaller. And then going back to what I first said, despite it flowing faster the air rate will still be the same.
So is it restrictive...no (and if it is, it is negligable)
A very common law is that the fluid rate is always constant for an ideal gas. That being said, the air rate of the snorkel at the bottom will be the same air rate at the top even after the kink.
A1*v1=A2*v2 -- this shows what will happen with the kink however. If you work it out it just means that because of the kink the air will flow faster at the top after the kink because the area is smaller. And then going back to what I first said, despite it flowing faster the air rate will still be the same.
So is it restrictive...no (and if it is, it is negligable)
Due to conservation of mass, mass flow in = mass flow out of our contol volume. Regardless of the cross sectional area the air must flow through, the mass flow must remain the same. mdot=density*velocity*area. Density is constant at the speeds we are dealing with, so as the area decreases the velocity will increase.
Your argument would suggest that two two-inch diameter pipes of the same length, one straight, and one with a number of bends and turns, both subjected to the same pressure drop will yield the same flow rate. Not the case
03-28-2006, 07:17 PM
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It makes sense that the air would just speed up at the bend, giving the same amount of air into the airbox that goes in. I was just afraid that the bend is so restrictive that some of the air, although it would speed up, would get built up, like a traffic jam, thus restricing the amount of air the engine would normally take in.
03-28-2006, 07:21 PM
#19
Originally Posted by slimjim8201,Mar 28 2006, 11:14 PM
Air is always an ideal gas. I assume you mean streamlines when you say flow lines? The air inside this snorkel (or any part of the intake system for that matter) will be highly turbulent. There isn't any area where laminar flow will occur inside the intake system. The flow is going to tumble around like crazy.
Due to conservation of mass, mass flow in = mass flow out of our contol volume. Regardless of the cross sectional area the air must flow through, the mass flow must remain the same. mdot=density*velocity*area. Density is constant at the speeds we are dealing with, so as the area decreases the velocity will increase.
Your argument would suggest that two two-inch diameter pipes of the same length, one straight, and one with a number of bends and turns, both subjected to the same pressure drop will yield the same flow rate. Not the case
Due to conservation of mass, mass flow in = mass flow out of our contol volume. Regardless of the cross sectional area the air must flow through, the mass flow must remain the same. mdot=density*velocity*area. Density is constant at the speeds we are dealing with, so as the area decreases the velocity will increase.
Your argument would suggest that two two-inch diameter pipes of the same length, one straight, and one with a number of bends and turns, both subjected to the same pressure drop will yield the same flow rate. Not the case
. Air is not an ideal fluid since it can be compressed (among other things that I mentioned).Yes I mean't flow lines
I also said I was assuming it wasn't turbulent since I don't have the knowledge (yet ) nor the equipment to record and analyze the data.And yes if you do have say 2 turns as opposed to one turn it will be different. But I am only talking about this one case (the snorkel) and not trying to compare it to other intakes. I'm just saying that the apporx. the air volume in is the same both at the beginning of the intake and at the end.
My model is a very basic one with lots of assumptions that I mentioned in the beginning. So far, I havn't learned enough to go into complex equations that involve many different factors such as viscosity / flow lines / turns / etc. Just giving a very basic idea
03-28-2006, 10:48 PM
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Wait wait wait. I know NOTHING about fluid dynamics, but it sounds like a couple of you guys do.
If I'm interpreting you both correctly, you are saying that the pinch in the snorkel is a non-issue, because the air will simply speed up to pass through there at a higher speed, thus flowing the same volume of air as a less restrictive snorkel, correct?
And by the above reasoning, there is NO detrimental affect to the airflow our engine needs, due to a kink in the snorkel, since the air speeds up to get through there anyway.
Now I'm generalizing and taking this to the extreme, but if this is true, by your logic, as long as air CAN flow through the pinch, it is a non-issue. But what if the pinch gets down to 1mm of space? It seems to me that there would be a point where the restriction would be too much for the engine to pull the same amount of air through there, correct? I'm not saying I know what I'm talking about (I don't), but help me understand.
As far as I've always known, there is an ideal intake diameter and flow for each engine. Ideally, you want as much air to flow through it, as quickly as possible. I've heard an engine compared to you sucking air through a straw. A coffee stirrer (too small) will not allow you to breathe properly. A paper towel roll (too large) will not allow the air to pass through quickly enough. There is an ideal diameter somewhere in between where speed AND volume are maximized, and for some reason... I have an inkling that it is a bigger diameter than that pinch...
It's pretty clear that the pinch is a compromise. Colder air, with the stock hood. But is it ideal? Well, both Mugen and J's sell snorkel intakes that maintain a larger diameter all the way from the induction point to the airbox, and they require a modification to the hood. If the pinch was fine/ideal/non detrimental, why go to the trouble of modifying the hood?
Or correct me if I'm wrong.
If I'm interpreting you both correctly, you are saying that the pinch in the snorkel is a non-issue, because the air will simply speed up to pass through there at a higher speed, thus flowing the same volume of air as a less restrictive snorkel, correct?
And by the above reasoning, there is NO detrimental affect to the airflow our engine needs, due to a kink in the snorkel, since the air speeds up to get through there anyway.
Now I'm generalizing and taking this to the extreme, but if this is true, by your logic, as long as air CAN flow through the pinch, it is a non-issue. But what if the pinch gets down to 1mm of space? It seems to me that there would be a point where the restriction would be too much for the engine to pull the same amount of air through there, correct? I'm not saying I know what I'm talking about (I don't), but help me understand.
As far as I've always known, there is an ideal intake diameter and flow for each engine. Ideally, you want as much air to flow through it, as quickly as possible. I've heard an engine compared to you sucking air through a straw. A coffee stirrer (too small) will not allow you to breathe properly. A paper towel roll (too large) will not allow the air to pass through quickly enough. There is an ideal diameter somewhere in between where speed AND volume are maximized, and for some reason... I have an inkling that it is a bigger diameter than that pinch...
It's pretty clear that the pinch is a compromise. Colder air, with the stock hood. But is it ideal? Well, both Mugen and J's sell snorkel intakes that maintain a larger diameter all the way from the induction point to the airbox, and they require a modification to the hood. If the pinch was fine/ideal/non detrimental, why go to the trouble of modifying the hood?
Or correct me if I'm wrong.