airborne

hmm, i wonder if that would be over kill or the ultimate in IC airflow, having a fan on either side one pushing one pulling. probably would really kill the airflow when they're not in use though.

when is your stuff coming in?

airborne

got the fan, here it is sitting on the ic.

probably could have gone slightly bigger, but not the 9 inch.

airborne

and here is the mounting hardware. the pins are very small and the backings are rubber so i doubt it'll hurt the fins any.

airborne

and the wiring i got. very good stuff. all the wires are labeled and the instructions seem very detailed. didn't look it over too much, i was just home for lunch.

Brentis

Took some pics of my setup. I didn't use the spal connectors - rather tie wraps. Worked awesome.

Here is the link

http://photos.yahoo.com/bc/jbg28/lst?.dir=/rx7&.view=t

LUV94RX7

iTrader: (3)

That's the one I'm getting. The 6.5"(330CFM) will fit but costs $22 more and uses 6AMPS and this uses 2.5 AMPs(295CFM).

The 7.5" will not fit.

LUV94RX7

iTrader: (3)

Looks great. When I get mine I will post my numbers. It's only 295 CFM fan and covers only 27% of the IC surface.

As you can see by a previous post I have all the air temp probes and gauge to do a accurate analysis of this feature under all conditions.

Those numbers will hopefully valuable to others.

Brentis

I was a bit skeptical that the 2.5 amp one could pull 295 if the 6 amp one could pull 330cfm. On the flip side I was hopeful that the 6 amp one pulled more.. if the 2.5 amp pulled 295 cfm<shrug>

airborne

just to clarify (not sure who is referring to what) the fan is the 7.5" 440cfm 5amp fan.

Radical Rotary Avantgard

Brentis, I don't see like you, any proportion of more amps and very little increase in CFM.
I still believe that somehow the CFM measure can't be that way off in the industry.
It just doesn't make sense to me.
Oh well, it looks good in there and lets wait for the test results.
Keep us posted Luv94Rx7.

LUV94RX7

iTrader: (3)

You picked a very nice fan. It covers 44 sq in of the IC my fan only covers 25 sq in. That is more important than CFM in my mind. The IC surface is 94 sq in. The only reason why I picked the small one was it was much cheaper and used much less AMPs. If my test are significant I'll get the one like users in the push type and put it on the front of the IC. I'm thrifty and want to know if it really is worth the investment.

Ken

PS: I just received my fan from UPS 10 minutes ago.

airborne

haha, thats a coincidence, mine was maybe an hour ago.

Brentis

ok read this - and give your thoughts.

I'm still looking for my reference to amperage vs. cfm.

http://www.ofgb.org/reference/Comput...an%20guide.pdf

It relates to computer fans but same theories hold. - haven't finished it yet but sounds relevant.

Radical Rotary Avantgard

Brentis, treid to open the file but my comp does not allows me to.
Can you e-mail it???

Brentis

do you have adobe acrobat installed?

I need your email.

Another possible theory is that assuming motor efficiency is the same, the fan with the higher amperage may not be as susceptible to flow resistance.

Just guessing.

Radical Rotary Avantgard

Brentis will send you a PM with the e-mail address.
Sorry about that.
I don't know since I am a computer illiterate.

I am seaching in fan flow measurements efficiency and none mention amps. It is all in CFM.
Even the goverment with the standards of measurements that should mean something.
I will throw this into the mix, modern cars have electric fans and they do consume alot of electric power that's a given, but why they put a big fan and not a little one to reduce weight, drag, save space given same electrical draw needs.
I think that we are ALL right and that a fan cooling ability is a combination of all these factors (in no order of importance):
# of blades
Electrical draw
Size of blades (width and length)
Pitch of the baldes
Area of coverage of the fan motor
Thickness of the radiator
Opening in front of the radiator
Etc.....
What remains to be answered, is how can you hold down the intake temps when you are stuck in traffic with the fans on instead of increasing the intake temps?
How can we solve this one because I am stumped.

Brentis

easy - mount the IC on the roof..

Radical Rotary Avantgard

Brentis, you are F...ing GENIUS!!!
How come I didn't think of that before is beyone me.
Thanks
Do you think I still need some kind of shroud or fans???

Brentis

ok - try this then.. www.coolflow.com/intracooler/intercooler.htm

LUV94RX7

iTrader: (3)

I did a quick and dirty test. I found that my shoulding before the IC is inferior. It sucks, at idle standing still, a lot of engine bay heat. I'll fix that with some duct tape or whatever in the future. I did an idle test for a long time(30+ minutes) in my garage. It was 70F degrees in the garage. With the fan on it dropped the temps after the IC by about 18F degrees compared to with the fan off. The PFC ECU Commander readings only went down 6F degrees. I think that is because the temp probe is right after the IC and the pipe to the engine heats up a lot standing still at idle and heats up the pipe and the PFC probe is just before the motor. I have to do alot more tests after I install it properly and fix the shroulding.

Brentis

Another issue as stated by Maddog (or is it baddog) was that the probe for air intake temperature gets heat soaked and doesn't report accurate temps b/c it is buried by the engine. So even while the air temp *may* be cooler on the end of the probe the end of the probe is hot from the engine heat resulting in poor readings - plus it hurts performance as well - as it isn't getting the right a/f

KevinK2

for two different 400 cfm fans, the rated amps will just reflect the flow efficiency of each design. the lower amp one will have less energy wasted beating the air.

for IC fans, one key issue is pressure drop, or static pressure rating. note in this spal link, rated flow drops by 50% with only 1/2" of water column pressure drop.

http://www.spal-usa.com/pdfs/6.5Fans.pdf

{note that the perma-cool 8" flow is only estimated to be 800 cfm ( at zero pressure drop). I doubt this rating, based on amps and size.}

For a back mounted fan, this drop is the static pressure under the hood, plus any vacuum created at the fan front. with no stand-off/shroud, like stock fan, air is pull thru an annular ring of area that is full of fins and tubes, so vacuum is very likely. if fan is just stood off 1/3" or so, it will recirc around the perimeter, for less vacuum but less flow thru core.

to hold down temps in traffic, best to use a shroud with stand off, and at least for dual 8" fans, make sure rad fan is on at low when IC fans are on. But with slow intake air flow, and radiant/conductive heating of the intake manifold and piping exit the IC, don't expect the big chill at the IAT sensor. But there is still merit in precooling the mass of the IC core (and exit tank), so when u do get going, the IC will quickly cool the charge.

Radical Rotary Avantgard

I will retire now from the subject, you guys are above me on this one.
Keep up with the reports on those fans.
Good arguments.

Brentis

Kevin I think I only understood half of that - but sounds good.

ech

Let's get back to basics - words hurt head.

This is the setup I described back - oo - on page 1 or so. You can see the fan, which was mounted with the nylon mounting straps that harmlessly go through the IC.

Above the fan is the temp sensor (a bit big, but it works)

Poking out behind the IC (well, in front of it) by the fuse box you can see the top of my control box - with the green LED.