sure this has been asked before but would it be better to run larger holes or smaller for best airflow (yes i know none is best)
the 2 i have are diamond shape 6mm or 12mm across at widest
thanks
Mark
Which ever has the lowest surface area. Will probably be the 12mm unless it has much thicker wire.
Go for the larger mesh :)
even if the surface area is the same the bigger holes wiil flow better. so basicly go fro the biggest you can!
Depends on how big the thing is your trying to filter !
I\'m guessing small animals, birds, and stones thrown up - so 12mm should be fine. :Giggle
I ran a tight mesh for a practice session last year.....biggest waste of money! Temps went through the roof!
Go careful
Quote from: marco;519261even if the surface area is the same the bigger holes wiil flow better. so basicly go fro the biggest you can!
If the holes are bigger the surface area will be lower.
possibly - but there should also be less drag on the air that actually makes it through the holes...
personally, i\'d say go for whichever weighs less (presuming made from the same material) - if it weighs less, and covers the same area, then it has more air holes... :D
I would say go for whatever has the bigger holes, irrespective of actual surface area. Reason being any mesh will disturb the airflow through to you rad/intercooler, however tighter holes will create a greater disturbance just behind the mesh, blocking more of the air trying to get to the rad/intercooler.
I\'ve been trying to make a similar decision for my fd as I\'m pretty sure the leaves that get blown on to my rad block more air than any mesh will. Been tempted to stay behind after work and use our fluid dynamics software to confirm whether my theory on mesh size is right or not.
I\'ve noticed that some mesh has a \'bladed\' profile - with the edges of the mesh actually have a slant to them - does that aid or detract from air flow ?
Also, mesh can be no worse than having the intercooler behind or in front of the radiator - that must present far more resistance to the air flow.
Quote from: Prof;519340I\'ve noticed that some mesh has a \'bladed\' profile - with the edges of the mesh actually have a slant to them - does that aid or detract from air flow ?
Also, mesh can be no worse than having the intercooler behind or in front of the radiator - that must present far more resistance to the air flow.
If the mesh slants inwards, I would expect air flow to be better as the slant will effectively help to funnel the air through the mesh producing less disturbance to the flow compared with a face that is perpendicular to the flow. However if the mesh slants inwards to one hole, usually it will slant outwards to an adjacent hole which may or may not be worse than an unslanted design.
Ooh the possibilities... :Tongue1
I agree with the comment about the front mount configuration, but if that isn\'t ideal (I say "ideal" in the loosest of terms and I don\'t really want to get into a front mount vs v-mount discussion as there are already threads on that subject) then you don\'t want to be doing anything that further reduces the effectiveness of the setup.
i knew this would start something :Thumbsup!
i have both here so it won\'t take long to swap them over as i did mastik it in,
unfortunatly i left my wind tunnel somewhere and car\'t find it and as for my fluid dynamics software i think the disc is in another case somewhere :rollin
consensis is bigger is better then:Thumbs-up
Mark
Don\'t mind me, I\'m a self confessed geek when it comes to this kind of thing :spank
At the end of the day, the proof will be in what your temps do with the mesh fitted. And as you say, it isn\'t too hard to change it around.
Quote from: od404;519349Don\'t mind me, I\'m a self confessed geek when it comes to this kind of thing :spank
At the end of the day, the proof will be in what your temps do with the mesh fitted. And as you say, it isn\'t too hard to change it around.
not calling you a geek my friend i love the way this kind of thread starts peoples thoughts, i learn from this stuff :yes
Mark
haha never meant to imply to you were. I was just admitting it :P
I too like these kinds of thread, especially when they challenge my thoughts and theories. I\'ll be interested to see how your mesh works out as like I said in my first post, I\'m looking to mesh my bumper.
just noticed you are in Daventry!
not a million miles away, its hard for me to gauge how much better it will be unless i can find a day with the same weather etc etc, i dont have any intake sensors etc i run a FB but hope i should notice soime difference
Mark
I heard once that for certain types of generic mesh, going above about 50mph create so much turbulence around the mesh that very little air flows through it at all.
air hits the mesh and gets scattered and very little actually goes through it. kind of bow wave effect
Quote from: RedRummy;519376I heard once that for certain types of generic mesh, going above about 50mph create so much turbulence around the mesh that very little air flows through it at all.
air hits the mesh and gets scattered and very little actually goes through it. kind of bow wave effect
My thoughts are that putting a step restriction in the airflow like mesh (or a plate with a hole into an exhaust) will create recirculating flow behind the restriction. This causes the flow to stagnate (slow down or even stop) in that area. I the case of one hole it isn\'t too bad, but with a mesh where there are holes adjacent doing the same thing to the airflow, you may find that the recirculating air actually blocks off flow through some holes, thus greatly reducing airflow.
To what extent this occurs and at what air speeds is however, a complete unknown. When you look at racecars, some have mesh some don\'t which makes me think it\'s more a case of judgement as to whether there is a detrimental effect to the engine rather than actually looking at the airflow itself.
Quote from: RedRummy;519376I heard once that for certain types of generic mesh, going above about 50mph create so much turbulence around the mesh that very little air flows through it at all.
air hits the mesh and gets scattered and very little actually goes through it. kind of bow wave effect
Spot on. The mesh becomes like a brick wall after a certain speed, where the air hitting it simply can\'t get through fast enough, so backs up in front, forming a standing wave. Not only does this knacker your cooling really badly, it meets the incoming air on the way back out of the bumper aperture and creates loads of turbulence which creates drag and knackers your aerodynamics. And makes loads of noise, for what that matters.
If you can live with all that, small holes look better, big ones work better (slightly)! :Thumbs-up. Both will look ****e after a year or two when they\'re all corroded and dented and manky, and you\'ve got fed up losing your fingertips trying to clean what is essentially a giant cheese grater! :yes
Mesh-free ftw!
heres a thought,
if you run with nothing there does the air still get through the radiator?
I think it does, so as long as the effective area of each of the holes in the mesh is bigger than the holes in the radiator then you wont see much change in the flow.
I say effective area because the holes through the radiator aretrapezoidal in shape, whereas most meshes are circular.
If my science is still correct the flow is going to depend on the square of the area. so even only slightly bigger holes will give a big benefit.
A further thought is that a thicker screen with \'aerodynamicly\' contoured (front to rear) holes may be very much better than a very thin screen with straight holes.
My bumper is meshed with the expanded stuff which is not strictly a flat surface as the edges of the holes are as such slanted. I totally agree that this is not as effective as no mesh but during my 1000 miles trip to the nurburgring my temps were lower than when I had a standard bumper with no mesh. Bearing in mind though that the hole in the front of my C-west bumper is about 3 times the size of standard. I wouldn\'t mesh a standard bumper.
I have the answer you are all looking for.....
Don`t mesh around with your bumpers dudes!:rollin
Seriously though, any mesh will help stop stones etc popping your rad which has to be a good thing! unless your car overheats that is!:cool
In another life I worked in conservation. One of the techniques we used for maintaining sand dune habitats (bear with me here, it is relevant, honest) was to simply erect chicken wire fencing along the areas that were being eroded by the wind. The way this worked is that the effect of passing through the mesh of the wire slowed the wind speed enough that it lost so much energy that it was no longer able to carry the sand particles it was removing, so they dropped out of the wind stream at the fence line. You just left it, went back a week or two later, and as if by magic, there was a new sand dune where your fence had been.
Now if you extend that theory to meshing your bumper, and compare the size of the mesh in chicken wire to that in bumper mesh and think about the profound effect that it had on how energetic the air flow was on the dunes, well.... What you\'re doing is reducing the amount of air getting through in the first place, and reducing the capacity of the air that does get through to deal with removing heat energy once it finally gets where its going.
Do it cos it looks nice (ish), yeah, but don\'t expect it to be anything other than a perfomance downgrade!
Race cars and the Time Attack cars in Japan seem to run with mesh. If it really affected performance I\'d imagine they wouldn\'t run with it at all, especially the Time Attack cars where they are not going to spend much time behind other vehicles that could throw up stones etc. The FD3S Time Attack cars run v-mounts and I\'d imagine even if they had their coolant under control their air temps would suffer with a restricted flow to the intercooler if the mesh was really having a negative effect. I don\'t know any of the physics behind it at all but surely if it hurt performance race cars wouldn\'t do it. Especially given that they could just replace stone chipped components after each race.