I am looking for intercooler cooling fan ideas

Okay this is my setup...

I want to run two 8" electric fans on the back side of the intercooler, but I do not want the fans to run 100'5 of the time. How do I set these things up? I would like it to be a some wait intelligent system.

So... 1. A switch on the dash is not going to work 2. Coolant temp sensors wont work. or will they? 3. What about a two speed system? Special fans? 4. It looks like each fan will pull about 5 amps. Should I just run them wide open? 5. I think it would be neat to run them at a lower speed under 3/4 throttle and step them up two 100% above that.

Thanks

what type of engine management are you running

coolant temp sensors dont seem like their readings would correlate to demand for cool intake air. it seems (to me, and im young yet) that it would be a good idea to have them come on when at open throttle, or maybe above 3/4. maybe have a relay close the fan power circuit when there is sufficient power from the tps signal wire??? this could all probably be done easily with megasquirt

Since I just have to say an idea and not actually figure out how to do it:

1. Turn them on off based on boost pressure.

or

1. Install temperature sensors on either side of the intercooler and set it up to turn the fans on/off based on the delta.

In reply to dean1484:

It's the stock 1996 WRX computer. But it's OBD I.

May be that easiest thing to do is have the intercooler fans come on with the radiator fan. I am using the stock ECU out put to turn on the radiator fan.

I would do it based on boost.. might be the easiest and most elegant solution

In reply to TJ:

Ya I have seen radiator temp probes that you stick between the fins, but that looked a little cheese. I would love a set up the let me monitor the before and after temps and adjust the on and off of the fans.

So if I want a two speed fan setup do I need special fans, or just the expensive controller?

Okay this thing is a little $$$ but what if I put the coolant temp sensor inline where the coolant exits the engine? It just seems that the coolant temp changes slowly. Am I making this to hard? Tell me to turn all the fans on at once. That would be the K.I.S.S way to do it, easy and cheap

Is the airflow supposed to go down through the intercooler when at speed? If so, I would just put two small fans without a shroud pulling air down at all times. That way at idle the intercooler isn't sitting there heat soaking because it is at the top of the chimney for all that engine heat. I think if you can keep out heat soak, the intercooler should work fine the rest of the time.

In reply to MrJoshua:

Ya they are going to heat soak like a subaru with out some fans on it. Maybe a switch on the dash is the best way?

I'm trying to think of an easy way to utilize an IAT sensor or two and create a controller that uses a difference in voltage to turn on the fans.

It seems kind of silly to run them constantly. Boost pressure might be a nice way to go as well.

Boost pressure is intermittent, usually. A switch based on that wouldn't be too good. Radiator fan wouldn't work out too well either, I don't think. IAT would be better, or a switch on the dash, or just leave them on. Spal brand fans are supposed to be pretty good. Make sure you know which way the natural air flow is at that point and get fans to help that flow.

Why not just run a small fan at full blast to stop the heat soak and then get creative with ducting so that the airflow increases with speed? A saw a turbo 3rd gen MR2 in Sportcompactcar (RIP) that had a "scoop" mounted under the engine that forced air up into the inter-cooler and then out through the engine cover

I'd just run them all the time to help with heatsoak.

Wire up a relay so they come on when you start the car, done.

I was thinking about something similar with a water sprayer.

http://autospeed.com.au/cms/A_2478/article.html

good point.. I have seen water sprayers.. what activates them?

mad_machine wrote: good point.. I have seen water sprayers.. what activates them?

http://autospeed.com.au/cms/A_0527/article.html

Dr. Hess wrote: Boost pressure is intermittent, usually. A switch based on that wouldn't be too good. Radiator fan wouldn't work out too well either, I don't think. IAT would be better, or a switch on the dash, or just leave them on. Spal brand fans are supposed to be pretty good. Make sure you know which way the natural air flow is at that point and get fans to help that flow.

You could also wire in a timer.. when boost (or even neutral manifold pressure) is achieved, the fans kick in and stay on for 30 seconds to a minute. This would keep them running the entire time you are running through the gears and deep into the throttle.. but once you backed off to cruise or sit at a light, they would time out and kick off

mad_machine wrote:

Dr. Hess wrote: Boost pressure is intermittent, usually. A switch based on that wouldn't be too good. Radiator fan wouldn't work out too well either, I don't think. IAT would be better, or a switch on the dash, or just leave them on. Spal brand fans are supposed to be pretty good. Make sure you know which way the natural air flow is at that point and get fans to help that flow.

You could also wire in a timer.. when boost (or even neutral manifold pressure) is achieved, the fans kick in and stay on for 30 seconds to a minute. This would keep them running the entire time you are running through the gears and deep into the throttle.. but once you backed off to cruise or sit at a light, they would time out and kick off

That is really the opposite of how you would want them to run.

When you are in boost, you are likely moving and have airflow over the intercooler.

but how much? There is a reason Porsche went with the HUGE whaletail on the turbo cars.. and not just for downforce. With the intercooler under the stock vent, it might get little to no air at all.

personally, if this had been my car.. I would have looked into air to water intercooling and a small radiator up front

mad_machine wrote: but how much? There is a reason Porsche went with the HUGE whaletail on the turbo cars.. and not just for downforce. With the intercooler under the stock vent, it might get little to no air at all. personally, if this had been my car.. I would have looked into air to water intercooling and a small radiator up front

You have a point, however I just like how simple an air to air set up can be. Ya you are right, a factory turbo tail would be an easy answer and one that I may end having to use. I have been thinking of the turbo tail as my fall back position. The factory tails are both expensive and ugly on narrow body cars. In fact the set up I am working on now will fit with out a wing. I like how clean these cars look with out the wing. But I have not found a cheap wingless hatch yet. Hell I may end going to a water / air setup in the end. Thanks for all the help guys.