Trevor

Check it out. Three reasons I threw this on:

-Supposidly the Mazda engineers noticed that SMIC's were actually getting backfilled with hot engine bay air when the radiator fans are blasting & pressurizing the engine bay and you're not moving very fast.

-Another problem is the *percieved* lack of flow thru the SMIC when going slower than 45 mph or so...judging by IAT's there doesn't seem to be enough pressure in the nose to move a significant amount of air thru the IC. My IAT's always creep up when I'm running <40 and drop back down at 45+. And yes...my whole nose & undertray is sealed up tight.

- It's difficult to keep a SMIC working optimally on the dyno...especially dyno's with bad cooling. This will help.

So here ya go...a SPAL 10" High Performance Fan - Pull Version SKU # 30102057.
http://www.spal-usa.com/fans/automated/tec...s/2057-2058.pdf
1070 CFM and 10 amp draw at 13V. Actually it popped a 10 AMP fuse so I had to step up to a 20 because I didn't have a 15. Spal makes good stuff. I've had 6.5" Spal fans on my old Typhoons' Air/Water IC radiators that lasted a good 25k miles of constant operation. Anyway it moves some SERIOUS air. The suction at the bottom of the duct is alot more than I was expecting!





Here's the button that turns just the IC fan on manually. I also designed a circuit with a diode so that when the stock fans turn on it turns on the IC fan too. That was kinda tricky but it works like a champ. If I hadn't used the diode the stock fans would have kicked on whenever I manually turned on the IC fan. Whats cool is the blue LED in the switch comes on when the stock fans turn on too, regardless of whether the button is pushed.

sonix7

have any numbers on temp drops or anything, does it help and if so, how do you know? looks good though. I am interested in what you find?

Trevor

I won't find anything out until next weekend. I lost the original motor last Tuesday at 1/2 throttle. I'm just trying to stay busy until the new motor arrives on Friday.

sonix7

lets turn this thread into a useful discussion, what is the real effect of doing this with an intercooler fan, I have read as many threads on this as I can, and of course it hasn't been supported or shotdown (scientifically) yet. I am wondering how this will help with stock hood vs. vented hood? Will the fan and proper ducting and a vented hood, be the ultimate solution to heat soak and cooling trapped hot air, or waste of money? anybody want to kick some science on this? lets go CFM guys, lets go engineers? let us know?

Trevor

I can't say for sure either way yet. I was just bored waiting on my new motor!

I can state that I do buy into and expect the fan to be somewhat useful. I mean, obviously I spent my money and time to do the mod.

The dyno was the big thing that motivated me to go ahead and install it. I can't see the SMIC working very well at my local dynos with their sub-par cooling setups. If they had one of those "squirrel cage" blowers that direct air into a very small area that might work well but I only know of one that has any of those on hand, and it's a Dyno Dynamics dyno that spits out low numbers up in Phoenix.

I will be getting a knightsports hood knock off later. It'll probably help out some more.

neit_jnf

iTrader: (17)

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/some-advice-crazy-ic-fan-mount-idea-452562/

sonix7

I read that thread a couple of times now, it does discuss the air flow and surface cooling, but does not talk about what effects it would have if you have say a scoot hood(example) or some type of vented hood. Will it pump the hot air out through the vents and draw air more through the car if you force the air through the duct, sealed to the core, fan on the other side puliing air, how efficient would that be? If you don't trap the air the fan is moving inside the eng. bay and vent it, what is that going to do? see what I am saying. It seems useless under a stock hood, if you can't vent it, seems like it might be more useful if there is a passage way for the air to come through hit the core and then be exited out. am I missing something here?

Kevin T. Wyum

The air would exit near the turbos and exhaust or the other side of the engine. I must be missing your point.

KevinK2

"Here's the button that turns just the IC fan on manually. I also designed a circuit with a diode so that when the stock fans turn on it turns on the IC fan too. That was kinda tricky but it works like a champ. If I hadn't used the diode the stock fans would have kicked on whenever I manually turned on the IC fan"

Good idea for having fan logic, but I'd revise the logic. You want rad and IC fans to run concurrently, in trafffic or at lights, or staging for a run. The IC only mode, stopped or at very slow speed, will reverse flow through the rad. Some hot air will get back to IC inlet. I would include a true off mode for hiway use, when ac may be on, or for winter use.

Among the worst heat soaks for a smic is hot summer traffic, esp with ac on. Throwing 200F air all around the IC, and backflowing through the IC core.

Like with the oem rad fans, a shroud prevents any reverse flow through the IC core when the IC fan is on. I think .01" aluminum sheet could be used to make a shroud with 1/2" stand off. Note exit flow area is reduced by the shroud, but that's ok since it's still much greater area than the duct's inlet opening.

Idea is to cool the core mass. It's ok if IAT's are slightly high at idle ... you want a precooled core when you have an urgent need for high hp.

ASP med IC (or crush-our-economy-china-copy) is ideal for spal 11" fans, thin or HD. Thin + shroud would be my choice.

Vented hoods should help, but I'd feel the IC exit pipe after 10 minutes in hot summer traffic before saying a SMIC fan would not help.

just my $.02

Trevor

The IC fan circuit is turned on by one of the two relays that the ECM controls (which I set up to flip on at 104C). I avoided the A/C fan relay so that the IC fan won't be on while on the highway with the A/C on (unless the car is having serious cooling problems and running 104C+). Good suggestion though...i wasn't really clear.

sonix7

so you guys think that with the fan, the vented hood would not do enough or it will help? just seems stupid to go through all the trouble of doing this if all you had for air escape is through the turbo exhaust area, which is not sufficient in dropping underhood temps at anytime. It seems like if the vented hoods help by themselves, then the fan should be frosting on the cake. No?

sonix7

maybe it will just circulate the air under the hood more and not help it escape through a vented hood at all? I have no idea. someone want to speak on this aspect of the convo?

Kevin T. Wyum

Vented hood will always help, with or without a fan, assuming it's a reasonable hood. The only thing it might do is reduce the amount of air cooling the exterior of the turbos and exhaust.