Location: Leonardtown, MD
Posts: 9,006
My VIN: 03572
I'm installing a new EU radiator and thought it's a good time to test the fans. I have the Special T fans from John and my set of OEM fans which I can run on my same test setup for compare numbers.
OEM radiator is 194 oz. EU one is 118 oz.
OEM unit is 1.257" thick. EU one is 1.681"
I think the thicker EU radiator is the reason it's almost the same air flow as the denser fins on the OEM radiator.
Last edited by Bitsyncmaster; 08-20-2012 at 05:36 PM.
Location: Stevens Point,WI
Posts: 2,470
My VIN: 6125
While I don't doubt that you'll be able to compare air flow between the fans using the setup you're showing, there is quite a bit more to how the fan will actually perform related to cooling performance...
Distance of the fan leading edge to the core as well as immersion distance of the fan into the shroud will affect how many BTU's the fan will be able to pull from the radiator in a real world scenario. If the fan mounting distances change between the various aftermarket fan vendors then this will change one or more of these parameters. We routinely do cooling performance tests on our heavy duty trucks where I work, and changing the core separation distance by as little as 1/4" can have a drastic impact on the performance of the overall cooling package. Same is true for fan immersion depth into the shroud.
So for example:
Even if an aftermarket fan "Brand A" can pull X more cubic feet per minute of air through an open tube than Brand B, Brand A's performance at pulling heat from the radiator may actually be less than Brand B's if the arrangement of Brand B's fan/shroud mounting is more optimal than Brand A.
Location: Leonardtown, MD
Posts: 9,006
My VIN: 03572
I completely agree this is not a test of cooling capacity. That would be more involved than I want to set up.
The radiator is bolted right to the fan shroud that is used in the car. So your first concern is not a problem.
Anyway here is the OEM fan test data.
Location: Farmington Hills, MI
Posts: 180
My VIN: 16619
This is Fan-tastic!
Though I am curious as how Cooling performance would actually differ from the two. I would love to borrow a Datalogger from work one weekend and stick some thermocouples around, or just monitor temp sensor voltage, or just ask HVAC department how they test this kinda stuff. However this would also require new fans lol.
Location: Leonardtown, MD
Posts: 9,006
My VIN: 03572
I did the no radiator test just to show the difference in current the fan draw.
As far as cooling, maybe the slower velocity has better cooling. I'm not a thermodynamics engineer.
The real test is running the car, knowing what your temp gauge reads and then change the fans or radiator and note if that temp gauge changes.
Posts: 605
Hi Dave,
just want to let you know some theory about fans.
Airflow V is proportional to fan speed.
V2 / V1 = n2 / n1
( V = Airflow, n = speed in rpm)
power consumption is:
P2 / P1 = (V2 / V1) ³ !!!!!
P1 = power at lower airflow (new fan)
P2 = power at higher airflow ( OEM fan)
(1130 / 800)³ = 2.8 !
P2 = 2.8 * P1 !!!!
Open for discussion. ( the formula is science, not invented by me
after some cans of beer)
Dave M vin 03572
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