Interior Exterior
Q:
I'm thinking of changing the plastic grills on the car to a mesh ones. Sereboff1 and I went to a mesh distributor here in So Cal. and found one we like. The only problem is the pattern takes up 40% of the surface, leaving only 60% for air to flow through. So should I be concerned with overheating? Or aero-dynamics since from my understanding (which I admit could very well be wrong) the airflow through the front grill through the top of the front clam helps force the front end of the car down.
thanks in advance for everyones advice,
Jacob
A:
I'm thinking of changing the plastic grills on the car to a mesh ones. Sereboff1 and I went to a mesh distributor here in So Cal. and found one we like. The only problem is the pattern takes up 40% of the surface, leaving only 60% for air to flow through. So should I be concerned with overheating? Or aero-dynamics since from my understanding (which I admit could very well be wrong) the airflow through the front grill through the top of the front clam helps force the front end of the car down.
thanks in advance for everyones advice,
Jacob
Also, just to add, the holes in the aluminum are approx. 5/32" (correct me if I'm wrong, Jacob) circular. It looks like this:
A:
I'm just guessing, but I'd tend to believe that the radiator itself slows down the airflow more than your mooted mesh would.
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Also concerned about the airflow through the side scoops of the car. I know I saw a much better throttle response when I had a new air cleaner put in at 14,000 miles (the old one was pretty dirty). Will I be choking the engine?
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The side vents might be a valid concern. I'd tread very carefully here. Can you lay the mesh ones over the top of the OEM vents and take her for a spin? Getting the OEM side vents out is really difficult, and generally not reversible without buying new vents.
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I highly doubt that the air flow through the radiator adds anything to the aerodynamics of the car, just cooling capability. Reducing the air flow by 40% would be a very large reduction - with that much reduction in air flow, I'd be concerned about over-heating the car. Blocking the air flow into the side vents might not be a great idea either.
If you want a quick test to see how it might affect things, take some cardboard cut to shape and block out 40% of the front grill and do something similar to the side intakes (maybe a combination of cardboard and tape). See if it makes a difference in operating temperature (and the amount the cooling fans run), and performance - it would help if you had a G-tech or something, but you could always use a stop watch to time acceleration over a stretch of road before and after blocking the vents.
Personally, I'm leaving my vents and grills alone, but if you must change them, I'd consider a more open mesh...
Edit: Additionally if the mesh is as pictured above, the air flow that would pass through such a mesh would be very turbulent - not smooth air flow at all - which wouldn't be a good thing either...
A:
Edit: Additionally if the mesh is as pictured above, the air flow that would pass through such a mesh would be very turbulent - not smooth air flow at all - which wouldn't be a good thing either...
Yes, which is why I think that your blocking-40%-with-cardboard test is not a good approximation of full covering with this mesh. However, I also think that the radiator itself restricts way more flow than this mesh. Thus I don't think that having the mesh after the radiator will have much effect. Using it at the nose of the car (ie in front of the radiator) I think would be quite a bad idea.
A:
Yes, which is why I think that your blocking-40%-with-cardboard test is not a good approximation of full covering with this mesh. However, I also think that the radiator itself restricts way more flow than this mesh. Thus I don't think that having the mesh after the radiator will have much effect. Using it at the nose of the car (ie in front of the radiator) I think would be quite a bad idea.
But blocking downstream air flow restricts the upstream airflow - it still restricts the total amount of air flow that can pass through the "system" (grill, plenum chamber, radiator, exit vents).
If the mesh is going to be used in the grill and the exit vents, block off 40% of both of them. It still isn't going to "distribute" the blockage exactly, but it's a better test than nothing, and it will give you some idea.
I'm suspecting that it will not be a good idea.
Using the early Miata as an example, some people install an aftermarket girll that only blocks about 20% of the air flow. Then they suddenly have a very marginal cooling system, or worse...
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Wrong grill material. That's perforated metal not mesh.
Look here:
http://www.customcargrills.com/products.asp?id=1
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Getting the OEM side vents out is really difficult, and generally not reversible without buying new vents.
Not so. Remove inner fender liner and remove two bolts. They come right out.
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But blocking downstream air flow restricts the upstream airflow - it still restricts the total amount of air flow that can pass through the "system" (grill, plenum chamber, radiator, exit vents).
Using the early Miata as an example, some people install an aftermarket girll that only blocks about 20% of the air flow. Then they suddenly have a very marginal cooling system, or worse...
The Miata example must be upstream of the radiator. There ANY blockage will cut down on the air pressure in front of (and thus through) the radiator
However, on the downstream side, it will make no difference to the flow if there is already something in front of it that blocks the it more (the radiator).
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Wrong grill material. That's perforated metal not mesh.
Look here:
http://www.customcargrills.com/products.asp?id=1
Oh really? Look more closely:
http://www.customcargrills.com/products.asp?id=56
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However, on the downstream side, it will make no difference to the flow if there is already something in front of it that blocks the it more (the radiator).
Yes it will. As long as the flow is not going supersonic, downstream air flow affect upstream air flow. Taken to an extreme, if you covered the entire exit vents, then no air flow would pass through the radiator even if you had absolutely no restriction the front grill or the radiator itself.
If you restrict the air flow coming out, if will restrict the air flow going in - even if there is restriction in the middle. How much it will restrict depends on a lot of factors, and may or may not be negligible.
I haven't measured, but I would expect that the area of the radiator (in square inches) is larger than the area of either the intake grill or the exit vents. This would allow for the restriction in the air flow through the radiator, and all things being equal (which they never are), allow the same air flow through all three portions of the "system" (grill, radiator, vents).
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Yes it will. As long as the flow is not going supersonic, downstream air flow affect upstream air flow. Taken to an extreme, if you covered the entire exit vents, then no air flow would pass through the radiator even if you had absolutely no restriction the front grill or the radiator itself.
If you restrict the air flow coming out, if will restrict the air flow going in - even if there is restriction in the middle. How much it will restrict depends on a lot of factors, and may or may not be negligible.
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I'm afraid I disagree with you. Your "extreme" example is not germane to my argument because in that case the downstream restriction is greater than the one upstream.
My point is if you have a restriction in a fluid stream that allows, say, only 10 liters per second to go past, then placing a "restriction" further downstream that allows 20 liters/second will not lessen the 10 l/sec flow upstream.
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Oh really? Look more closely:
http://www.customcargrills.com/products.asp?id=56
Yes, they offer 1 perf. and 10 stamped wire and woven wire products. Take a guess why?
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Yes, they offer 1 perf. and 10 stamped wire and woven wire products. Take a guess why?
I'm just saying that even they still refer to it as "mesh".
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Edit: Additionally if the mesh is as pictured above, the air flow that would pass through such a mesh would be very turbulent - not smooth air flow at all - which wouldn't be a good thing either...
I don't think turbulence is going to have much of an effect, I doubt there is much laminar flow of air going through the radiator anyways. The turbulence probably helps the diffuse the heat, anyways (anyone feel free to correct me if I turn out to be grossly wrong here). I think the 40% coverage is more of an issue.
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My point is if you have a restriction in a fluid stream that allows, say, only 10 liters per second to go past, then placing a "restriction" further downstream that allows 20 liters/second will not lessen the 10 l/sec flow upstream.
Agreed, except we don't actually know that the radiator is the restriction in the system. As I said before, I suspect that the area of the radiator is greater than the area of the intake grill or the vents. I.E if the radiator is a 20% restriction of the air flow, but it's 25% more area, it would not be the restriction in the system. Even if it is nearly equal, restricting the downstream air flow will cause a decrease in the air flow of the system, even if it's not the largest restriction - how much and if it even matters would have to be measured.
This is one of the things that was beat into my head during my aerodynamics classes many years ago. It would appear that downstream flow shouldn't affect upstream flow, but it does - if only in that it changes the speed of the air flow passing through the system.
I don't think turbulence is going to have much of an effect, I doubt there is much laminar flow of air going through the radiator anyways. The turbulence probably helps the diffuse the heat, anyways (anyone feel free to correct me if I turn out to be grossly wrong here). I think the 40% coverage is more of an issue.
You're right, the turbulence isn't going to affect the air flow going through the radiator, and it might even improve the heat transfer. You are also correct about the 40% coverage. The turbulence of the air going through the mesh grill will "mess up" the air flow through the grill and most likely decrease the volume of the flow.
A:
Thanks everyone for your expertise, thanks to your input we decided to cancel our order and went with a wide stretched metal mesh. We'll post pictures as we go along.
cheers,
Jacob
A:
Thanks everyone for your expertise, thanks to your input we decided to cancel our order and went with a wide stretched metal mesh. We'll post pictures as we go along.
cheers,
Jacob
I think that's the right decision, if only for aesthetics. The perforated panel looks too dominant IMO. I would probably also go with a black or dark grey mesh.
- J