Im not too bad with fusion 360. You think I might able to salvage it by redesigning the fan shroud and laser cutting some vents in it that might help?

I know it’s probably not worth the effort but if I’m in the hole here I just want to do something to make me feel better about the money I lit on fire lol

 

For craps and giggles here’s what I came up with. It has about 73% of the surface area of the current shroud accounting for fan holes. Will that equate to 27% more usable surface area of the radiator? I have no idea but you guys are pretty smart so I’m sure you’ll educate me on why cutting holes in the shroud won’t help.

My perspective (assuming my understanding is correct) is that doing something like this is great for when your moving and high volumes of air are passing through the heat sink fins. But at idle, they decrease the efficiency of the fans by having so many open air gaps. Perhaps rubber flaps that can seal shut at idle would help balance the trade off. As for it helping idle temps I’m sure nothing beats raw static pressure. Curious as to what you guys think.

 

It's hard to tell from the one photo of the CSF shroud but I would expect the greatest improvement in flow through the radiator would come from increasing the space between the radiator and shroud, effectively creating a plenum prior to the radiator entry. Or more simply, I think the fans are too close to the radiator. Of course, any space between the two must be sealed and not allow air to escape.

 

There’s certainly room to do that. In fact creating a slight funnel shape so the shroud might really help out those fans and allow them to pull air from the entire rad surface rather than just from the two cutouts. I like your idea a lot.

another thing I’m going to try (now I’m in full experimentation mode lol) is I’ve flipped one of the spal fans upside down so they are now counter rotating. This doesn’t change the direction of airflow, just the direction of the blades one fan is spinning compared to the other.



Counter Rotation

Same direction


At least if my car loses its rudder I’ll be able to use differentiating thrust to keep it flying straight.

the real reason I’m gonna give this a shot is rather than having both fans spinning in the same direction creating a lot of turbulence where both fans meet, this should smooth out the airflow between the two fans and increase the efficiency of the fans. Enough to keep the car cool? Probably not but I’m bored and it’s Saturday so why not find out.



EDIT: According to the hand anemometer (coincidently produced by the same company that makes the butt dyno) counter rotating seems to have made a genuine improvement. Before I could feel noticeable “flat” spots in airflow and it seemed a quite a bit weaker.

Counter rotating= felt like I had uniform airflow at all corners of the rad and felt closer to the stock fans movement of air. Certainly not the same amount stock fans are still stronger, but quite the improvement.

 

Anemometer readings confirmed what you all obviously knew but admittedly the results weren’t far off except in the low speed tests.

stock fans
low speed 340 ft/min
high speed 472 ft/min

CSF fans
low speed 314 ft/min
high speed 433 ft/min

Did these tests with everything mounted in the car, I wanted to see what they were actually pulling through the condenser and the rad.

What really shocked me was this though.



Naaaaaaasty.


I’m gonna test fit the new rad in the car and check the fitment of the stock fans. I’ll run another airflow test with both sets of fans so see just how much the airflow improves.

This will also either confirm or debunk if the stock fans can at least be used with the CSF radiator.

 

Pretty funny. With the CSF rad and fans installed, they are now testing at the original stock fan CFM numbers.

CSF radiator + Fans installed

low speed 354 ft/min

high speed 472 ft/min

Next test will be of the fitment of the stock fans onto the new rad. Although I think it might be close, I have a feeling they should be fine.

pics of all the CSF hardware installed.

 

I'm curious how you are applying the anemometer to get CFM readings.

 

To try and keep it consistent so I’m not holding it at different distances I’m holding it right at the center of the lower splitter, and measuring the airspeed being pulled into the radiator.

Should I be doing it differently?

 

Probably fine for relative airflow. Anemometer's read air speed, not volume. Likely feet per minute.

The issue with using airflow as a proxy for cooling capacity is on the spall fan unit, the air is moving over a smaller area. This is less efficient for heat transfer.

 

Ahhh I see okay. I’ll edit my posts then to reflect that. My use of “CFM” is incorrect.

 

A discussion of the CSF radiator and fan kit on another thread has led me here.

Do you think that old gunked up radiator can be cleaned up? If yes, I’m going to take mine out and clean it.

I’m looking forward to whether the stock fans fit the CSF radiator.

Thanks for your work documenting this.

 

For starters I can tell you the stock fans do fit! They even include a bracket so that the larger turbo fan shroud can be fitted as well. My reservations were that the fans would fit the radiator just fine, however things will be seriously seriously tight in the front of the engine bay, especially for that lower radiator hose and for the AC and PS pulley. I ordered new mounts and hoses so when those come in before final reassembly I’m going to give the stock fans a test fitment to see if they’ll fit in the car no problem.

As for your first question, you can absolutely take the time to clean up a stock radiator. A shop should be able to clean both the interior and exterior and back flush it out to remove any build up in the coolant passages. I opted for the radiator because I needed one anyways, mine has the classic leaks in the winter but is fine in the summer issue due to the end tanks beginning to fail. I’m sure even in the summer some air is still getting in.

can you send a link to that other thread? I’ve been wanting to see what other people have to say+ see if anyone else has installed it.

 

https://rennlist.com/forums/924-931-...-radiator.html

 

Awesome thank you!!!

 

Hey guys, so far so good working on replacing the hoses as we speak. Question for you guys with the Lindsey kit, is it normal/ safe to trim the upper rad hose? Mine is hitting the alternator when installed.



The lower hose to the tank is fine, but the hose that transfers the coolant from the block to the rad is giving me a little trouble