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finishing up some pending projects i had on the car, i installed my headers and it put my o2 Sensor directly sitting inside my AC fan, my primary fan functions properly and the car doesnt overheat, but i wanna replace the AC fan with a slim line fan....what do you guys recommend to be the CFM for this fan? I saw some fans on ebay, ranging from 1500 CFM and up...not sure if 1500 would be adequate to run with my stock cooling fan for the ac....any ideas?
i run 2 14" 2000cfm fans on my evo radiator. just try to get the biggest that will fit and blow the most cfm's. mine are both hooked up the the stock connectors on the fan controller also.
try to get one with s blades instead of the straight blades
the CFM ratings "differ" from company to company. so while one company can claim 1500 cfm, what they use to measure is not the same as another companies.
I would say buy the biggest fan u can fit from a good company. I like my Spal fans (their CFM ratings are lower than other companies but I believe are more accurate) and I am using a 10" slim as a pusher for my AC fan on my Galant. I am also going to be installing a 9" fan as a pusher on my 2g this summer.
I believe my fan is only 1000 cfm so "1500" should be enough
Im using mishimoto fans and shroud on my evo radiator. I think the shroud is the most overlooked thing. When you mount a fan directly to the radiator, its only drawing the air through the area that the fan itself covers. When you have real shroud, its drawing air through the entire radiator so the fan has a better effect on cooling. I was running a single 1600 CFM 14" PermaCool puller with no shroud and went to twin 10" mishimoto pullers with a shroud and I dropped about 12 degrees. I can do back to back dyno pulls and the temp never goes over 190. I can sit in traffic for an hour and it never goes over 190.
Quote:
Originally Posted by Stewi
One thing about shrouds is they can also cause air flow restrictions. You have to remember they are intended to help the fan create a stronger "force" of air being pulled through by the fan. This is a great setup for a daily commuter, stop and go traffic, and moderate highway driving. The shroud is basically a funnel and while driving at highway speeds all of that air is being forced through one opening which is smaller than the surface area of the radiator.
Putting it in simple terms, the Radiator core is the cooling surface area. Keeping as much of the surface area "clear" will allow plenty of air flow through the radiator core for efficient cooling over a wider surface area. When you start adding shrouds to a cooling fan assembly (depending on the size of the shroud), you are adding a restriction point.
Now I am not sure how much of the radiator these shrouds you are using cover, but this is something that needs to be considered when looking at adding a shroud. A lot of people that run shrouds which cover the majority of the radiator core will modify the shroud to add "flaps" to the side of the shroud. These are made from a piece of rubber which stays "closed" at low speeds, then as air flow increase (such as at highway speeds), the flaps are pushed open from the air and allow greater airflow through the core.
Also, just by doing multiple pulls on a dyno and not seeing any increased heat cannot and should not be taken into account when discussing cooling fans/shroud setups. Your vehicle is stationary, and sometimes with a large auxillary fan placed in front of the vehicle. This goes back to the basic air flow principals explained above.
As mentioned above about surface area, you went from a single fan to a dual fan setup. Even though the single fan was a larger diameter and a 1600cfm rating, your dual fan setup is covering more surface area directly and drawing air through the radiator core evenly compared to a single fan which would definitely result in a lower temperature.
Take the above for what it is worth to you as the reader, but do some of your own research and make a decision that you feel is best.