View Single Post
Old August 31st, 2010, 03:11   #30
Veteran Member
Join Date: Dec 2006
Location: Belgium

Originally Posted by Ben Dur View Post
today the skis cleared up just enough for me to pull my little green TDI up to the garage to swap my crap cone filter with my stock air box

i first compared the size of these filters
by bending the paper filter around into a cylindrical shape
beside the cone filter it looks like this

as you can see the paper filter is significantly larger in all dimensions
it also has more pleads

this means the total surface area of the paper filter is significantly larger.
without actually measuring and doing all the math my guess is that its between 2 and 3 times the surface area of the cotton filter

i set up my wet/dry vac to test the flow differences
i was not able to reach the flow limit of either filter however

(yes i did this project on the ceiling)

with the vac ON
it pulls zero vacuum with nothing connected

and with my hand covering the inlet the vacuum pulls approx ~3in.Hg of Vacuum

next i hooked up each filter to the vac and tested each

each pulled 0 (zero) vacuum
both times the needle seems pegged right in the exact location the needle sits with no vacuum applied as well as the same amount pulled by the shopvac with no restrictions

finally i installed the stock air box

my conclusion
connected to a 5hp wet/dry vac neither the stock air box nor a cone air filter produce a measurable amount of restriction measured by my inexpensive equipment

Wouldn't it been easier to just take a lenght of clear turbing, fill it with water and use a ruler to measure the pressure drop..?
'99 Black Ibiza GT90: 2260v, ARL bottomend, rosten rods 81mm slugs, 17:1 CR, 35/38mm exh/in valves, 02M, 305mm discs with Brembo calipers, OZ Superturismo 16"x7.5J, .............
Dyno'd area, Old VNT20 setup dyno'd 192whp
Rub87 is offline   Reply With Quote
Page generated in 0.06995 seconds with 8 queries
[Output: 17.79 Kb. compressed to 16.24 Kb. by saving 1.55 Kb. (8.72%)]