Why does my blowhole push more air than my backside exhaust?

[Quad]

hi

this is my setup:

30cfm intake
50cfm rear exhaust
50cfm topside blowhole

all 80mm fans. i just put in the blowhole today (with a chrome grill) and it feels like its pushing A LOT more air than the exhaust, even tho they are both identical fans. the exhaust has that grill that comes with the case (the one with the holes). i remmeber when i first installed the exhaust, the air felt VERY powerful...now it doesn't feel that way anymore.
any ideas?

thx in advance

 

[J3anyus]

Two things...



<< the exhaust has that grill that comes with the case >>


The OEM pressed grills (the ones you're talking about here) generally have very bad airflow characteristics. Chrome grills on the other hand, like the one on your blowhole, have good airflow characteristics. So your blowhole fan has a lot more breathing room, allowing it to move more air.



<< i remmeber when i first installed the exhaust, the air felt VERY powerful...now it doesn't feel that way anymore. >>


There's 2 possibilites for that...one is that your fan is dying (not likely), the other is that you're just used to more airflow now, so it just seems like less, although it's the same.

If you want to try getting more air out of that exhaust fan, you can always take a dremel, cut out that OEM pressed grill, and replace it with a standard chrome grill. Be careful about doing this though, metal shavings will be everywhere and will kill any components they touch. If you think you want to cut it out, PM me, I've done it before and can give you pretty good and safe instructions.

J3

 

[Damascus]

Have you tried disconnecting your blowhole fan and checking
the airflow of the exhaust again?