Advice Needed for External Box

[Styyn]

I'm going to be building an external box over the next weekend or two and could use some expert advice. Current plan is to run an Iwaki 30RZ to two 2-342 Fedco's in parallel, with a t-line in the external box, feeding an RBX and Fusion HL. A 3.2E @ 4.0 1.54v and X800 Pro -> XT @ 1.5v will be producing the heat. I'm using the RBX in my current setup, so I'll stick with that until the skies part and Cathar blesses the world with the Ag G5 (January-ish?).

Now for the questions:

1) Any better options than the Fedcos? Thermochill 120.3 comes to mind, or possibly an auto radiator that's readily available State-side? (Saw Cathar's Honda Life/City rad, but can't seem to locate anything comparable over here.)

2) Assuming I go with the Fedco's, would the 30RZ be preferable to a standard 30RL with the G5? I guess what I'm asking here is, given this setup, would you estimate the headloss across the loop to be low enough that the RL's increased flow would make a difference?

3) I'd like to use a dual cage blower mounted opposite the rad(s) and plan on hitting Autozone up for a catalog before I start calling the salvage yards. I'm a newbie with electrical, however, so I've got a number of questions for this:

a) What's the best way to go about controlling the speed? Bear in mind I've no background when it comes to building circuitry (like the array of "on/off" switches I saw on Cathar's box), but I'm entirely willing to build something from scratch if someone can give me a step-by-step or point me to a resource comprehensive enough that I won't roach myself because I'm self-taught .

b) When browsing the catalog, anything in particular I need to be looking for in terms of electrical specs? 12V? 24v? Max amp draw?

c) AC would be preferable I guess, but I do have a featherweight, pos Codegen 350w with 12A (!) on the 12v rail collecting dust that could be used. Which would be an easier application?

Seems like I had more questions, but this is excessively long as is, so I'll spare y'all and thank you for reading this far

[JamesAvery22]

1) hey if you have money to burn dual 120.3s would be nice =)
Most car radiators are aluminum, so you want to stay away from that since you have copper blocks
2) Im actually looking to do the same thing (dual 2-342s and a lot of blocks) but Im thinking of going with dual MCP650s. Cathar is looking at a new 12vdc pump, Im waiting on the results on that before I decide though. The MD-30RX is the one people recommend IIRC. That would do your system justice Im sure.

3) I dont have any blowers so I cant help you there. If its not 12vdc or 115v ac then you are going to have to buy a powersupply of some sort unless its like a 24v blower that can run on 12v but at a lower speed... I know a lot of large DC axial fans come with built in controllers, maybe some blowers do also.

When you get working on it be sure to post a lot of pics good luck

[nikhsub1]

1. I'd go with 2 or 3 of the 2-342's if you have the pump for it, and the 30RZ is the ticket. They are single pass, no need to run parallel, run them in series.

2. 30RZ, no question about it.

3. I see lot's of folks making BADLY designed external boxes. Look how the guys that know build them, Cathar for example. What you want to do is have the box as air tight as possible, you only want holes in the box for the fans/blowers and rads. With the rads, you need to seal them up nice in the box to the opening for the rad(s). Then, you have all the fans/blowers EXHAUSTING out of the box. With this negative pressure, cool air is forced IN over the rads. Obviously the more rads you have in the box, the more fannage you will need for good airflow over the rads. But with 2 or 3 rads, you could have a nice quiet and efficient setup.

*Edit*
Look at Cathar's post, 2nd one: http://forums.overclockers.com.au/sh...hreadid=300690