There are far too many zip ties involved for this to work permanently so throw out some ideas. My main objective was to mount the fan without going through the core. The main problem with this setup is that nothing is holding the bottom of the fan and it has the potential to bump. The fan is a 10in summit fan flowing 1250cfm.

 

Dude, just go through the core. It works.

 

IMO, you'll need to fabricate some brackets that will attach to the top and bottom IC "plates" (they are basically for structural purposes; they are not a functional part of the IC). Probably use some short, flat sheet metal screws to mount the brackets (obviously taking care not to drill into the functional plates, as well as use screws that are too long; Loctite should keep them from vibrating loose). Plastic zip-ties will eventually fatigue and break due to the engine compartment heat.

 

Sorry this is no real help to your question but I was just curious if it actually is worth putting a small fan on the aftermarket SMIC to draw more air in through it. I have an ASP medium and I was thinking of doing it, but I wanted to find out if it was really worth it? How have your results been? Much lower intake air temps?
Thanks, Jerry

 

and make sure to put a relay with your wiring or a fuse...my friends supra caught on fire since he did not put a realay or a fuse on his fan,,

 

If you are going to mount it permanently like your pictures suggest, then look at incorporating a fan shroud, or the fan will pull in air from the gap between the IC and the leading side of the fan (instead of through the IC core).

 

I have a fan that covers the KW made cooler,( same as the M2 med ) .I turn it on in slow traffic .I do not see a great difference in temps .If the temps are high and I turn it on they do not drop that I can see but with out it they may go up more ,Its a hard call ,worth it or not .I will keep it because the work is done but I do not think it will make a big differance . My air temp senser is mounted in a Gready elbow fuel injecter mount .The senser is screwed in to a nylon part that mounts in the injector mount so the heat soak is very little .

 

It appears to me that he has the fan shroud itself butted up against the IC core (the fan shroud is offset a bit from the aluminum bar mounted across the inlet/outlet). Nonetheless, good point.
I doubt that once the IC is heat-soaked that a fan will make a significant difference in lowering the intake temps; a fan will affect only part of the IC's overall surface area, and any fan (despite manufacturer cfm claims; those numbers drop like a rock when they are mounted next to a 3-4" thick IC) cannot generate the airflow to significantly lower the IC's structural temperature. Turning on the fan before encountering traffic will help, but the problem is the lack of airflow across the complete surface area of the IC, which requires more pressure than cfm--two different things.

 

I have a perma cool 12" high performance puller fan (1650 cfm) on my M2 Large. I was lucky enough that the previous owner already had gone through the core to mount one and the mounting points aligned exactly with the new fan!

I agree thet the rated cfm drops a lot when in front (or behind) a very thick core but testing out the wiring I turned on the fan to push air and I could feel a lot of air at my feet in front of the nose of the car! I then switched the wiring and I can definetely feel the air move a lot being sucked through the ic core.

Air is definetely moving a lot there which must help prevent heat soak, and that's exactly what I want. I'm also thinking about getting a vented hood and that will help some more.

 

I second what neit_jnf is saying. It does make a difference. Damian's track car has a Flex-a-lite fan on the back and with it running the temp of the outlet side of the IC drops to near ambient within a minute or two, even after a full bore session on the track. As a comparison, the other side of the IC (and all the other parts in the bay) are painfully hot.

At any kind of speed though he turns it off because it's more of a restriction than it is a help given any kind of airflow in the front of the nose.

I plan on eventually doing the same thing with my IC.

 

Sorry, but "a lot of air at my feet" and "definetely feel the air move a lot" doesn't equate to significant airflow through the IC or intake temp drops. As I said before, it's pressure that plays a role in getting airflow through the thick core of an IC, not cfm.

 

That's because it was already being cooled by airflow at speed when he came off the track. Allow the IC to heat soak with the car sitting, and there's no way a fan will lower the structural temp by itself "within a minute or two".

Don't get me wrong, a fan is better than nothing. And I would rather use a SMIC than a FMIC. It's just that I've found the effectiveness of an IC-mounted fan is somewhat limited.

 

Nope, if he doesn't turn on the fan the entire IC is bloody hot. If he turns it on for a minute or two the outlet (and the outlet only) side is cooled down near ambient.

By 'near ambient' I'm saying within 10-25 degrees on a 90 degree day. It depends on how long, pavement etc of course.

People at the track are often surprised how well it works.

[Edit] I should mention that this is with an ASP style large intercooler. Just a FYI[/edit]

 

I find that extremely difficult to believe because there is very little airflow inside the IC while idling, so even if it was providing some effect on the core, it would take longer than a "minute or two" to have an effect on the outlet side (and I'd think it would have an effect on the inlet side as well, since the entire IC is aluminum, and heat transfer would be fairly equal). But that's just me.

Good for Damian if it works.

 

The only way I've noticed that big a difference is touching the core outside the fan (f'n hot) and then touching the core covered by the fans (warm). This is my 2nd IC and second IC with a fan and I think I'm of the "better than nothing" opinion. BTW, its 90+ out today and in city driving with little traffic the PFC registered 60+ AIT all the way. I have the craptacular pettit hot air intake.

 

Yes, I agree that it seems odd. People are always surprised when you can touch the outlet (cold) side of the ic, but burn your hand on the inlet (hot) side.

The fan config etc was all on the car when he bought it, and the utility of it is still questionable since for road course driving you turn it off anyway and then it's just a restriction on the backside of the IC.

 

Actually, cfm IS a measure of airflow, volume (cubic feet) of air per minute, across the fan. Ok it's the maximum rated for the fan with no restrictions, but it has the capacity to create a pressure difference across it's circumferencial area to cause air to move at it's rated cfm.

It's pressure difference, what causes fluid flow. For example, a fuel pump flows MORE with LESS outlet pressure. The fan will still create the same pressure difference when installed on the core but the core will create a restriction thus lowering the cfm. The "pressure", like you say, is there.

The only way to really test it is with an air flow meter or air speed meter, since I don't have any of these I rely on the moving air that I can feel with my hands. Maybe an infrared temperature meter, or some thermocouples but again, I don't have any.

Using your reasoning, I should take out my radiator fans as well, because they don't provide any significant airflow. All the hot air I feel moving is in my imagination.

 

I don't think that was Kento's reasoning...

 

Sorry, but I never said cfm is not "a measure of airflow". I said that pressure is what will get airflow through the thick core of an IC, not cfm. CFM and PRESSURE at a given point are not one and the same.

You're not even close to understanding my point. Nearly all fan cfm ratings are made with a 0 static pressure drop. Putting a thick IC core in front of it, and those ratings fall like a rock because most fans generate very little actual pressure (You can have a fan that is rated at "15,000 cfm" actually generate very little pressure at a given point). The turbulence that develops at the core surface restricts the amount of airflow that can actually get through the 3-4" thick IC core at any given time. Drive the car at speed, and there is obviously much more pressure involved (given that there is proper ducting to create the necessary pressure differences), which is what forces a large amount of airflow through the core. The thicker the core, the larger the pressure drop, and the more pressure required to get significant airflow through it.
My post was not meant to be insulting; only stating the obvious. Such as the fact that there's a big difference between a radiator and IC core, as well as fan and shroud construction between the stock and aftermarket units. How about we try using your "Capt. Kangaroo logic": when I turn my fans on, I can feel hot air moving. Thus, there's no way my engine can overheat...

 

I didn't mean to be insulting either and I understand what you're trying to say about the big pressure drop across a very thick intercooler core.

But I'm trying to say that at least the fan I'm using is doing something, I can feel a strong rush of air moving into the ic duct. It might not be much or provide any significant help, but it's a lot more flow than with no fan at all.

I even found a flaw in my ducting thanks to it, the previous owner had trimmed it to fit and left a small open space where the ic fan is pulling hot radiator air into it. I could feel the difference in temperature across the general duct opening and felt this hot air on the side and was like, wtf? So I looked closer and found the opening where the hot air was being pulled through. I'll cover it and then it'll only pull air from the nose.

And btw, my car never overheats and I've tracked, auto crossed and drifted on cool to very hot ambient temps.

And I don't know who Capt. Kangaroo is

 

The IAT sensor is located under the uim and doesn't really give an accurate reading on intake temps unless you move it to the elbow.

A very nice way to put it.

The benefit of ducted fans (radiator or intercooler) comes from when the car is not moving very fast and heatsoaking as opposed to running the car on the track or on the highways. At freeway speeds, there is little benefit to running your fans because the air is being pushed through the rad/intercooler at a reasonable rate natually.

If your car is heatsoaked and at idle, just running your radiator fans can drop the temperature dramatically

An example with my car (coolant temps recorded by pfc) fully warmed up:

Freeway speeds without fans on 85-90C
Freeway speeds with fans on 85-88C

City speeds without fans on 96-98C
City speeds with fans on 88-90C


I imagine that air temps would react in similar ways. I would post numbers for the IAT sensor, but since mine is located under the UIM, it would be faulty readings.