Saml01

iTrader: (9)

Heres mine for the sake of post count.

I used slot blanks for computer cases. HA

RotorNutFD3S

iTrader: (33)

Thanks Ferdi. I'm still deciding on how I want the fans to run anyway.

I actually cracked it because it was uneven when the bit broke through. Didn't crack any more holes however after I made sure it was on a level drilling surface.

sixshooter, like I said, I'm still learning about all this, so maybe instead of comments like that, you can actually add something insightful. Chances are I'm not the only one researching this, and chances are people will read this later and learn something.

ftjandra

iTrader: (6)

Just to clarify what sixshooter meant with air flowing backwards through the idle fan. I agree 100% that that could/will happen. It's not sucking the air backwards through the radiator, but within the shroud itself. Picture this: instead of the radiator, mount your shroud on a solid wall. Turn one fan on...air will be sucked backwards through the idle fan. Like I said, dividing the fans with a piece of weather stripping would easily prevent this.

--Ferdi

sixshooter

iTrader: (12)

As explained by the others, since you spaced the fans back away from the radiator, you have created a common space that they are both pulling from. Previously they could only pull from right in front of themselves which meant through the radiator in each of their individual locations. Now each fan can pull from anywhere that the common airspace allows, both through the radiator and through the neighboring fan, if it is idle. If both fans are running, then there will be no back flow through an idle fan, because there is no idle fan. If you wish to run the stock configuration with both fans operating independently, you will need block the airspace between the two fans to cause each one to act on independent airspace in the cavity you created. As Ferdi pointed out, a simple piece of weatherstrip between the fans and separating the airspace into two separate cavities will solve that problem if you wish to proceed in that manner. I thought it was a good and simple solution. I was surprised, I guess that you didn't visualize what I was referring to in my first post, but apparently Ferdi and others did. I was a bit snide, and I apologize for that. I just thought you weren't trying to understand. I tend to get quippy when I think I detect laziness. Sorry about that.

If it matters at all what I think, it is a very effective design and should perform much better than stock. I also think that it looks quite nice.

hustler

iTrader: (6)

inn like flynn.

Savington

iTrader: (31)

People who don't track their cars should stay out of threads like this.

Atlanta93LE

iTrader: (5)

Here is an interesting anecdote regarding plexi shrouds on a race-car, but not a miata:

I was running an Alfa Romeo Milano in One Lap. Not long track sessions, but enough to push the cooling system in summer heat. The car was having temp issues, so we tried plexi shroud. Temps were datalogged lower on our test track, but not low enough. We COMPLETELY shrouded and sealed the mouth opening straight to the rad, directing all possible air through it. On the straightaway at our home track for testing, the pressure building on the front of the rad was so high the plexi fan shroud broke right off. We put the fans back on and left the mouth shrouding, and all was perfect. Temps were great.

Conclusion: I won't ever put a flat fan shroud like that on a track car if I have properly routed airflow through the mouth.

RotorNutFD3S

iTrader: (33)

Thank you for clarifying. I didn't understand what you meant from your first post because I didn't properly compare my shroud and the OEM shrouds, it wasn't until Atlanta93LE mentioned that each fan is shrouded individually that it "clicked" in my mind, that was my fault. But I am definitely trying to understand this properly and claim no prior knowledge, other than the fact I ran a shrouded setup on my turbo Saturn and it helped greatly. But because I ditched a/c in that setup, I ran both fans concurrently, so now I'm trying to figure out if I should run it like that, or seperate the fans like stock since now I'm adding a/c.

Ben (ben91) mentioned mouth shrouding yesterday, I had already planned to take the leftover plexi and use it to make some shrouding there (waste not, right?), however, that's a little unnerving. But I don't mind trying different things to find out the results. The good thing is, if I have to ditch the shroud, I'm only out a little money and the time it took to make it.

Saml01

iTrader: (9)

First of all, if your radiator is properly sized and cooling system sorted out the fans shouldnt turn on when youre moving. There is no way the fans can draw more air then your car moving through it at 50mph.

Second. The only time the shroud makes any difference is when stopped when the air will be drawn from every part of the rad.

Thirdly. With a flat shroud like the one in the OP you probably hurt flow when moving because instead of hitting a funnel like the stock shroud, the air is hitting a wall of plexiglass probably hindering flow through the rest of the rad.

RotorNutFD3S

iTrader: (33)

^^^ That makes sense too for the flip side of the argument. However, because of space, I can't use the OEM shrouds, especially not the a/c fan one, nor make an effective funnel shroud without costs going way up.
As of today, I'm tempted to take it off and add some rubber flapper doors like other shroud makers use on their designs. Wouldn't be too hard to do. Would help while driving, and they would shut while stopped so the fans can do the work.

Saml01

iTrader: (9)

More complicated then its worth, seriously. How much cooling power do you need when stopped? How much cooling power do you lose by not sucking air from the areas not covered by fan? Answer: Not enough to matter.

Savington

iTrader: (31)

I agree. However, with the FMIC setups 95% of us run, proper airflow through the mouth to a radiator is a pipe dream.

Atlanta93LE

iTrader: (5)

^ A sacrifice I'm willing to make Still, I want the air to have one only eventual path: through the radiator.