My 1994 Turbo Legacy had a turbo that seemed to suck air in while the WRX has an intercooler that just allows air to flow over the cooler.

Question is this: The Intercooler helps the turbo by cooling the return down thus causing better boost. People use water sprayers to spray water onto the intercooler to make it perform better. I know this works because during the 106'F summer last year, I put crushed ice all over the intercooler and took it for a spin. MAJOR difference - all the boost was back. Once the ice is gone, it seems to loose 20%.

Ok, I was supposed to ask a question...

The coolant system on the WRX (and all cars) allows the coolant to cycle out of the engine and into the radiator. Two forms happen - one, forced air from the car moving forward, and two, electrical fan induced cooling as well.

It seems the WRX intercooler works soley on the purpose of forced air when the car is moving.

Why isn't there an electrical fan on the intercooler to help make it perform better? Would that actually help?

Hey Infy, interesting question.... I've wondered the same thing. My theory is that the cooler air is needed when boost is built, when the car is accellerating. I guess that the pressure of the air forced through the hood scoop would equal what an elec. fan would push, and it creates itself when needed. Actually, having the entire I/C surface open (without a fan blocking it) might moove more air than a small double fan. Don't know for sure....

It sure does like the cooler temps around here though. Speaking of which, are you thinking about putting the summer rubber back on too, seeing as how winter seems to have taken a "by" year here in UT?:rolleyes:

Are you thinking about putting the summer rubber back on too, seeing as how winter seems to have taken a "by" year here in UT?

Naw, not until April. Probably first week of April I'll put them on. No sense in dirtying them up. I've been considering selling them and getting a set of 18"'s instead. Who knows.

And yea, it's been rediculous this year. We've had 1" snow this year. Terrible.

Actually Austin on this board has actually done this. Check out the pics and test stats in this thread:

http://forums.nasioc.com/forums/showthread.php?s=&threadid=238876&highlight=spal

Two 6' SPAL fans fit under the stock scoop with no modifications. Doesn't do much at speed when there's air moving, but in stop and go, and Auto-X he registered MUCH cooler post-IC temps.

I bought the fans from him after his little experiment, and hopefully I'll be installing them this spring. Just need to get a controller for the fans.

this is a great question for the "factory forced induction" forums, but i will try to help...

yes, people have put fan on their intercoolers but in my opinion it just blocks the flow of air at higher speeds, you aren't making boost when you aren't moving, so why worry about cooling down the air from the turbo? and when you are moving, there is plenty cooling provided by the stock intercooler and scoop. if you are really concerned, an STi intercooler/scoop, and waterspray system will greatly decrease the chance of heatsoak while stuck in traffic. i do not feel that fans are an acceptable method to cool down the air in an intercooler.

besides, subaru has spent the last 10 years refining their design of their intercooler. they have made it bigger and added lots of improvements. if they felt the intercooler needed fans to cool it down, i'm sure they would include them. just my thoughts on this matter. have fun!

Originally posted by eric m.
yes, people have put fan on their intercoolers but in my opinion it just blocks the flow of air at higher speeds, you aren't making boost when you aren't moving, so why worry about cooling down the air from the turbo? and when you are moving, there is plenty cooling provided by the stock intercooler and scoop. if you are really concerned, an STi intercooler/scoop, and waterspray system will greatly decrease the chance of heatsoak while stuck in traffic.
Just looking at the fans in question, I don't think there's enough blockage to worry about, especially at higher speeds. Water spray systems are good. If you remember keep them filled and if they're automatically triggered. Personally, I'd rather not have to worry about it. Summer temps here in STL can reach high 90's to over 100 with 100% humidity for a significant portion of the summer, so any help on a daily driven car is good. Plus, in an auto-x situation, I'd think that the combination of high boost levels and relatively low speeds would tend to soak the IC even more.

Originally posted by eric m.
besides, subaru has spent the last 10 years refining their design of their intercooler. they have made it bigger and added lots of improvements. if they felt the intercooler needed fans to cool it down, i'm sure they would include them.
Point taken. Unless they were too expensive to add. Not that IC fans are high on SOA's priority list.

You make some good points, but if you read the first post Austin makes in the above link, he does have some pretty cut-and-dried temperature numbers to back up his claims. I forget the exact ratio, but isn't a 5 degree (or is it 10 degrees?) temperature drop equal to 1% more hp? If so, and you can reduce post-IC temps by 80 degrees as claimed, that translates to a fairly significant hp bump. In addition, the added safeguard of not stuffing overly hot IC air into your engine right off the line at high boost.

hey, if you want to do it, do it. but i really feel that there is a large margin for error with do-it-yourself temp testing, and i feel that subaru knows what they are talking about. on the other hand...who knows. fans might work better but might also be too expensive to install in a production car. so if you are going the fan route, good luck, and let us know how it turned out. :)