Ideas For Fitting An Air Filter

[markrnorton 0]

I'm slightly confused as to how you can say surface area hasn't much to do with flow rates. Try sucking through a straw, now try sucking through a mouthful of 20 straws. You will notice the difference!

 

This is very basic fluid mechanics? Not 20 years worth.

 

 

now you're just being stupid and insulting.

 

if K&N produce a replacement perfomance panel filter for a car, it has the same dimensions to fit in the original airbox, but it's filtration properties and flow rates are totally different.

 

Surface area and mass flow rate do have a link, but not how you image.

 

i can also see you dont understand fluid mechanics. your straw analergy is also incorrect. the single straw will be easier to draw fluid through as it has less resistance. try it. put 20 straws in a bowl of water and see if you SUCK.

 

dont confuse mass flow rate over resistance.

 

Thanks for the thread Jon !

I have a small panel filter in my airbox.

[Batfink 201]

and you might want to note that the weaves of filters from the likes of k&n are actually quite unrestrictive. They are too big to work like paper filters - the oil on the weave is what catches the smaller particles

[markrnorton 0]

and you might want to note that the weaves of filters from the likes of k&n are actually quite unrestrictive. They are too big to work like paper filters - the oil on the weave is what catches the smaller particles

 

that was my point batfink, filter composition is what usually dictates mfr, not physical size.

Edited January 23, 2006 by markrnorton

[DrSeuss 0]

now you're just being stupid and insulting.

 

if K&N produce a replacement perfomance panel filter for a car, it has the same dimensions to fit in the original airbox, but it's filtration properties and flow rates are totally different.

 

Surface area and mass flow rate do have a link, but not how you image.

 

i can also see you dont understand fluid mechanics. your straw analergy is also incorrect. the single straw will be easier to draw fluid through as it has less resistance. try it. put 20 straws in a bowl of water and see if you SUCK.

 

dont confuse mass flow rate over resistance.

 

Thanks for the thread Jon !

I have a small panel filter in my airbox.

 

Ok, no need for any of this aggro. My original point was, all things being equal (2 pieces of fabric of the same weave, impregnated in the same manner) and it IS surface area that dictates whether it'll be a restriction. It is a compromise when designing a filter as to whether you get better filtration or better flow rates. You misquoted me, belittled my opinion and now call me stupid. Not very fair.

 

As for 20 straws in a bowl of water, I'd still appreciate a better explanation then just being told i'm wrong. I did fluid mechanics for a couple of years and did my own practical experiments of air flow rates and restrictions. I'm no expert but i do understand the basic concepts.

[Rippthrough 98]

Ok, no need for any of this aggro. My original point was, all things being equal (2 pieces of fabric of the same weave, impregnated in the same manner) and it IS surface area that dictates whether it'll be a restriction. It is a compromise when designing a filter as to whether you get better filtration or better flow rates. You misquoted me, belittled my opinion and now call me stupid. Not very fair.

 

As for 20 straws in a bowl of water, I'd still appreciate a better explanation then just being told i'm wrong. I did fluid mechanics for a couple of years and did my own practical experiments of air flow rates and restrictions. I'm no expert but i do understand the basic concepts.

 

 

That just stems from you having to lift 20 times the mass.

 

As for ram-air, most fueling systems should be able to adjust themselves enough from the base map to compensate for a ram-air effect, and the point of it is not so much to pressure the airbox, but to keep it at atmospheric. Most intakes usually have around half a psi deficit from atmospheric.

Edited January 23, 2006 by Rippthrough

[Jonmurgie 2]

Right, I have sorted out my air filter issues... in a rather majestic way I feel

 

Basically I grabbed a Pipercross panel filter for a Subaru Impreza from PowerStation with the intention of cutting it up to fit in the headlight:

 

So armed with a screwdriver and a heat gun I managed to prise the headlight apart and clean out all the sticky stuff:

 

I then set about cutting the panel filter down to size so it fitted neatly inside the headlight back:

 

Then it was just a case of a couple of screws to hold the back and front parts together and bingo, a perfect airfilter for my ducting:

 

I can (and probably will) change the filter anytime so I'm really pleased with that, thanks to one of my boys for coming up with the idea

[Jonmurgie 2]

Just fitted the light back to the car and it all looks sweet!

 

[pacey205 2]

Looks like a good way of getting around it John, nice neat job as well.

 

Michael

[smckeown 1]

interesting thread jon. I am undecided whether to run with an airbox yet. I have been researching on the caterham forum and came across this interesting thread on distance between trumpets and airbox

Edited March 13, 2006 by smckeown

[Jonmurgie 2]

Blimey, that's a bit interesting isn't it... I was actually hoping to get a power run without the aribox at all sometime soon so it will be interesting to see if it has any/much effect on the power. The airbox they are talking about is silghtly different to the one I'm using as I've got the Elise airbox Bernard Scouse does ( http://www.auto-teknix.co.uk/roadelise.htm ) and in that thread they are on about the Caterham airbox ( http://www.auto-teknix.co.uk/caterham.htm ) although it looks like it's just the inlet size that changes.

 

I was also going to do some testing of shorter trumpets as well, 45mm seem to be the other size people use. Would be nice to have some direct back-to-back testing of this kind so we know exaclty what's going on with things!

 

Good find though Sean

Edited March 13, 2006 by Jonmurgie

[James_R 3]

Interesting thread, looks along the lines of a hertz resonator type idea, you can calculate the correct volume based on engine size cams etc.. sure it's in the 4-stroke tuning bible. Will have to dig about.