Got the fans for free from a friend after my main fan died at SOW two weekends ago. 1/8" ABS, cut to the shape of the rad. Used the 8 stock fan mounts, cut two 11" holes, mounted the fans up, and used OSH open-cell weatherstripping to seal it all off. The first fan is on when CLTs go above 174 or something, the second fan is on when CLTs are above 174 AND the switch on the dash is on.





bonus pic of my dirty-*** engine bay.



look at the pics/i am ready to debate

 

pretty sweet, any idea what cfm they are rated at?

 

They are rated at 810cfm each.

 

So they probably pull close to 1100 each, they tend to underrate them from what I have been reading. I may be getting rid of the stock fans soon for more space and have been comparing a few fans.

 

FWIW I use the Spal twin 11" thick fans that come with their own shrouding. Minor mods made it fit my CSF "race" rad.

Check out the flap valves which open when the fans are off to let air through:

JayCorp Technologies - SPAL Dual 11" Fan with Shroud

 

I agree. My 16" spal is the god of all fans. With a 32f ambient it takes 4 seconds to bring the coolant temp down 8* (f). But then again it startles other drivers at the stop light when it comes on. Straight blades and low profile ftl when it comes to noise.

 

that is pretty trick.

 

Sav, what difference did you see while street driving?


I may need to bite the bullet and pickup a set. I just dont trust these ebay fans especially in the South Fla summer.

Anyone wanna arrange a group buy?
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Nice Sav I like that setup. I also like the black ABS shroud as opposed to the usual Lexan solution. I am using two 11" Spals on my radiator as well and may copy this.

 

I haven't driven around staring at the CLTs yet, but it used to idle between 197 and 200 in the driveway. Now it idles between 194 and 197. I'm trying to get back to the track sometime in February so I'll know about track cooling more then.

 

Sav -

Just curious as to why you used a flat, sealed backplate. Aren't you going to sacrifice some of your airflow? Especially if you have your second fan tied into the stock harness. It won't kick over until you activate the A/C clutch circuit...

- L

 

with the mods he did it will come on WITH the first fan WHEN his switch he wired in is on. Otherwise it acts normally. The reason behind the big ABS plate is to pull as much air as possible when the fan/fans are on.

 

Are you asking why I used a shroud at all? 2/3rds Cobra did a quick test with a leaf blower in front of his FMIC, and the fans pulled more air through the radiator even with the leafblower going. With direct airflow to the radiator, I would likely run one smaller fan to keep temps low when I am stopped, but with the FMIC blocking all airflow, the shroud helps the fans use the entire radiator.

I have the second fan on a switch that ties or unties it to the main fan. I haven't felt the need to run the second fan on the street, though. (these ******* are loud.)

 

Let us know how it goes... FWIW I have seen one turbo car with the 2/3rds Cobra shroud overheat at speed (on the highway and at the track). Altitude was a factor, but it revealed the restrictive nature of that style of shroud.

Unless you are overheating at idle or in low speed traffic I would ditch the flat shroud.

 

Like you, I'm running a pair of SPAL fans, with the second tied to a switch just below the radio. However, with the top-mounted intercooler and fresh air ducting to each heat exchanger Corky and I did not shroud the rearmost radiator.

I wouldn't expect an issue while moving, but was unsure as to what result you would get when stopped.

Thanks for the insight...

- L

 

That's because the fans create a pressure differential to make air move through the heat exchangers. Driving doesn't. You'd have to go like 170 mph before pressure ever starts to build up significantly in front of the heat exchangers.

Personally, I'm not too impressed with that style shroud. It has a lot of compromises in its design, though it is simple and cheap.

 

Do elaborate? With fans just producing a pressure differential, I never really considered the shape or taper of the shroud to be a consideration.

 

IMO-

Fans are too close to radiator so they won't pull air evenly. If they were bolted right to the radiator, they're pull air like this:

http://i231.photobucket.com/albums/e...orDrawing3.jpg

That's a koyo radiator and 11" fans.

As you get the fans further and further away, they will begin to pull air more and more evenly. However, with your design the corners and edges don't get as much air flow. How far away are the blades of the fans from the core of the radiator?

I'm not saying it doesn't "work", but it's not ideal.

 

Pat, what would be the ideal distance from the radiator to have fans with a shroud like savingtons?

 

The mounting bosses are 3/4", and they sit just about flush with the core (a little overlap with the endtanks). Then you've got 1/8" of ABS, then the fanblades. So mabye an inch or so. The problem is that I can't go back any further, Pat. I have the RB tubular sway and the RB sway brace, and the fans touch the brace as is.

I did consider that when I was thinking about how I was going to mount the fans. I wanted to get them as far back as possible to utilize the whole rad. This is as far back as they'll go in my car. :(