chucker

iTrader: (4)

Werd. Plus it's stock so you don't have to dick around making an unneeded part.

Gotta say, his little video was enlightening to see. I knew the flow would be low but that was WAY low.

What's that say about the potential affectiveness of an extractor? If there's so little flow behind the rad, then how much air can we really be extracting? I mean, an extractor would need to create a very low pressure to have notable impact, right? It would seem to be more usefull to just get fans with bigger ***** and call it done.

Has anyone taken pressure readings from various locations underhood, with and without an extractor? Before and after temp readings under controlled conditions? I'd like to know before I cut a big hole in hood.

jayc72

iTrader: (14)

Is that a function of the shrouding or the additional CFM the fans add? My argument isn't about the fact there is a fan present, my arguement is about upgrading over the stock fan.

I know at speed I rarely if ever get above 97* that the fans come on at. So I guess I'm sayin' good enough.

The second video wasn't launching for me, I'll watch them again and maybe I'll get some sort of Revelation.

Okay watched the video. I still stand by what I've said. MY experience in real life with out a leaf blower indicate that the coolant temps don't get high enough to start the fans. Maybe I don't drive hard enough or something. But running a under high load at lower speeds like autocross is going to stress the cooling system as much if not more than running high load at high speeds.

Or I'm talking out of my ***.

chucker

iTrader: (4)

don't bother. there's very little flow behind rad. that's all you'd need to know

ZX-Tex

iTrader: (15)

In my case it was due to the over-the-top IC piping configuration and the resulting tilt of the top of the radiator rearward to clear the piping. It would not have worked without slim fans.

There will indeed be some efficiency loss due to flow around the tips of the blades if they are not close to a shroud. It is the same kind of tip loss seen on turbines and airplane wings. But, this loss is relatively less critical for high aspect wings or blades. And if the small fan works well enough, well then it works well enough. Empirical data is hard to argue with.

Ben

iTrader: (33)

thinking out loud here... the fan is a resistance to air flow when the car is moving. in that case, perhaps the smaller diameter fan will increase the car's ability to flow air through the rad and out the extraction vent while driving. if the previous is true, then it would be true that the smaller fan is in all ways better.

Roar believes it to be true...

hrk

iTrader: (6)

When you get the shroud/fan matched together so the fan is pulling air through the radiator instead of circulating air behind it, your motor will thank you at the first red flag you experience on the track. Flag was seen way too often on Road Atlanta last weekend and that is not good when one has to stop car from full blast without any cool down time.


hrk

levnubhin

iTrader: (30)

Damn, this thread is making me wish I never threw my old fans away. Even though they didnt work. Off to the U pull it........
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Ben

iTrader: (33)

Care to post a couple pics of your new set up please?

samnavy

iTrader: (7)

Perhaps this is the latest and greatest front in DIY miata mods.
I'd like to see 2 main fan shrouds installed side by side... rather than one main and one AC fan.

I don't think a 12" will fit in the AC housing... but it sure looks like it will fit in the main housing.

$42 shipped
http://cgi.ebay.com/ebaymotors/x2-12...mZ160271774883

Braineack

iTrader: (62)

12" will fit for sure in the main housing. later this afternoon/eving ill do the cooling one and see...I know it's a touch smaller.

Fireindc

iTrader: (13)

It looks good, maybe ill do this.

I also agree with Ben, it seems if you have HIGHER cfms with a SMALLER fan, cooling would be increased all around (high an low speeds).

Braineack

iTrader: (62)

I would assume the fans spin freely as airflow passes through...i dont really see them disrupting flow whatsoever.

Braineack

iTrader: (62)

Fan seems to be generating a lot more heat at my feet than I've ever remembered on a cool summer day. hell, on a hot summer day for that matter. Makes me think a lot more air is passing through at idle.

hrk

iTrader: (6)

Here is links to photos, sorry for not embedding them in thread because of their size.
Front
http://russmarshall.com/d/19637-1/P3130007.JPG

Intercooler side
http://russmarshall.com/v/cars/cmc7/...geViewsIndex=1


Oilcooler side
http://russmarshall.com/v/cars/cmc7/...geViewsIndex=1

Spal fan
http://russmarshall.com/d/19602-1/P1161345.JPG

So far it has worked great, water has not exceeded 215 deg F under run, and fan should have enough cfm to keep thing cool in case of sudden stop from full song and car kept on idle. This setup has not been tested like this yet, luckily.
Previously temps went 230 and beyond on a 100 degree ambient day during 30 minute session, then I had to start feathering throttle.

I saw one Hoosier DOT track tire suffer damage after red flag last weekend. Tire had bulges on about 270 degree area on the inside sidewall. While we were watching it at the paddock it suddenly bursted without further provocation than sun heating. It was removed and unloaded at the time, driver had pulled in because the car felt wierd after second red flag in one race. Tore 4" long rip on bulged area. Scary stuff.

hrk

Braineack

iTrader: (62)

A/C fan done.


Here's some actual real magnehelic gauge testing data I found:

Both fans raise the atmosphere .25 ~h2o when running. Both drop it .25 just in front of blades, obviously.

I was able to have the a/c fan drop it .50 inches of water in a certain sweet spot, but alas I couldn't find a spot on the other side where it would increase that much.

I do need the 12" to fully utilize the shrouding...toward the outside edge of the cooling fan, it tends not to raise the pressure as much, obviously due to the size in the shroud. the a/c side raises it evenly across the entire opening.


Now I need to test the same with stock fans mounted.

So in someone wanted to use this as an example, buy a 12" for the cooling fan and 10" for the a/c.

you can also see in my picture with a 2" radiator, i don't have much wiggle room with a 7/8" solid bar.

scottv

iTrader: (3)

I just got my Mishimoto radiator so figured I would put new fans on there...I bought two 12" fans from this seller and got them in a few days (and they don't screw you on shipping like most of the ebay sellers...1/2 price shipping on the 2nd fan so $15 total shipping for 2...$55 for two fans shipped: http://cgi.ebay.com/ebaymotors/12-EL...mZ250282592683
...they seem to be of pretty good quality, although I haven't hooked them up yet...I'll be getting a piece of Lexan from Home Depot and fabbing up a shroud and adding that and the fans to the radiator, then installing that and my ebay intercooler!!

Saml01

iTrader: (9)

Im curious, did you have to cut out the new fans from their factory shrouds or can they be easily separated?

Braineack

iTrader: (62)

they unscrew. new ones are screwed into the plastic, with new holes.

kenzo42

iTrader: (6)

I wonder how well pusher style fans in front of the radiator would work. I remember seeing the newer Mercedes SUVs (ML) w/ fans mounted pusher style.

When I upgraded my radiator in my Integra, my AC really suffered b/c of the thicker core. There was constant cycling. I ended up getting a slim fan placed in front of the condensor and no more cycling. Although the slim fan was now directly next to the condensor, instead of having to pull air through the radiator first, it seems that pusher fans still can help an overheating car if space permits.

I was going to wire up a relay so I could get 2 AC fans running at once, w/ my main fan. I don't know if Miatas have enough room in front of the condensor to mount a fan though.

hustler

iTrader: (6)

how did you get the stock shroud to mount so shallow? I have the "coolradiator.com" aluminum rad, and hopefully mine will fit between the sway bar brace.