Fan thickness in a external W/c box

[Gulp35]

I am building a External W/c box with the radiator mounted like DodgeViper's Case( sideways windtunnel).

The case is 7 1/4" wide so the fan and shroud have 5 1/4" to take up.

My question is this:
Since thicker fans(38mm) have higher static pressure capabilities they are able to push more air through the rad. But since they are thicker the shround has less room to spread out the air. While a 25mm fan ( the type I have now
) would have more spread out airflow while not being able to push or pull as much air.

Which setup would give me the best temps assuming the fans have the same airflow at 0 backpressure?

I'm leaning toward the 38mm fans but that means that i have to go buy another component to my system

[bigben2k]

Why don't you try to close the gap between the impeller and the housing? You can try electrical tape: that should give you a bit more air pressure.

I don't think it'll give you any better cooling temp though, but it's a simple effort to try it out.

[Gulp35]

I'm going to setup my rig with this and then MAYbe switch to the 38mm fans later. I'll try to post pics of it at the moment soon (I think it looks cool ).

[Gooserider]

My question is this: Since thicker fans(38mm) have higher static pressure capabilities they are able to push more air through the rad. But since they are thicker the shround has less room to spread out the air. While a 25mm fan ( the type I have now ) would have more spread out airflow while not being able to push or pull as much air.

No question about it... Go with the 38mm fans!

Airflow through a rad is very much a function of pressure, and the higher pressure from a 38mm fan will give you much better flow than a 25mm fan. The difference in duct length should not be an issue as long as you have 1-2" minimum spacing off the rad face. If you have 5.25" worth of space, then it should be no problem to have a shroud about 3" wide, then the 1.5" thick fan, and a bit of extra space for slop. Note that it is also best from both a flow volume and noise reduction standpoint to have the fans suck through the rad rather than blow at it.

Gooserider