Thanks for the clue, I was looking under your tag and couldn't find it, for some reason I thought it was you

 

Does water injection not solve this problem? Mine is set to start spraying at 3 psi. It just seems like it would cover the bases regarding heat soak.

 

Good question, I know water injection cost more than the 35.00 or so I have spent, and I don't have to fill the tank, or better yet, wonder if I filled the tank :-)

 

Didn't read the whole thread but this switch or any switch doesn't make sense.

What is the purpose of having a fan on the IC if you are not going to cool it when the car is standing still. IMO that is when it matters the most as it is prone to heat soak more at those times. I had mine IC fan wired to be on at all times when the car was running. No sense on waiting for it to get warm to cool it. Just keep it cool.

 

I can understand if you don't want to spend the money on water injection. Regarding having to fill it up, or wondering how much is in the tank, there is a float switch on most of the units that illuminates a LED telling you it's time to fill. On a relatively stock car you it does not use that much wiper fluid. 300cc/min at full flow if I remember correctly. I think that is what I am running. You would have to be breaking the speed limit for an extended period of time or be on a race track to have to worry about running out very often. It will cool many times more than a fan on the back of the stock intercooler. Not trying to discourage, as your project sounds fun, just being factual. If you want to lower the IATs this is your best option.

 

Hello Mr Rick
This point has been made a few times in this thread, and, as I said earlier I hadn't considered heat soak in my initial project, just low air flow at low speed and high boost. However, since I have some time right now, I have rewired the switch to come on when the Rad fans come on. So if the fans are on the SMIC fan is on, by the way this is NOT a Stock inter cooler, it is a Greddy. See my earlier post where I state that I like the idea and will work on it.



I'm not sure this is the "best" way I have my PFC fan set at 87 and at that temp I get full Alt voltage (14.4vdc) to the SMIC fan. I didn't expect the SMIC fan to activate when just the AC was on, however, it seems to back feed through relay #1 and I get about 7VDC and the fan runs about half speed. I don't think that would hurt anything,but I am not sure. Any thoughts from you Electrical guys would be appreciated.

Thanks for the info on Water injection, I am aware that water injection will reduce the IAT a great deal, I am trying to be as simple in my approach as possible, as I said up front, my concern is Low Speed High boost, such as coming out of a corner. My approach doesn't take up any of the available space, and is much simpler. I am still running the twins and while I do plan to run as much as 15PSI boost (I have 360 thrust bearings) I am up grading the fuel system now. I don't think I will require Water injection for this level of boost, and I can always add it. Thanks for the input.

I haven't had a chance to do the measuring with and without the fan, it may not be very helpful at all, but when I get the fuel and tune straight I will find time to record some runs with and without the fan running.

 

Water injection is great for stock boost levels. Running anything above stock boost on the factory intercooler is asking for trouble in my opinion. The fan is not going to cut it.

 

Interesting idea! Subscribed :-)

 

Just an update to what I have already stated, and some additional info.

In the schematic above I notice that I left out a representation of the in line fuse between the battery and the pressure switch, It is there. Please send any comments about how I might better wire this SMIC fan so that it comes on not only at low boost but whenever the cooling fans come on. Right now, as I said above I only get about half voltage when the AC is on, due, I believe, to back feed through relay #1 and I get about 7VDC and the fan runs about half speed. Not sure what problems this might cause if any.

Additionally it seems that when I use the term SMIC (Stock Mount Inter Cooler) everyone ASSUMES this means Stock inter cooler. This is not the case, maybe I wasn't as clear in the text but the pictures should have made it clear. This is a Trust/Greddy Large SMIC.







Since it is a much larger and efficient IC in the Stock location with larger and custom ducting, I think the Fan will be plenty of cooling for Stock boost levels. I believe Water injection isn't needed for "stock boost levels" if it were Mazda would have done something about it, especially with a larger more efficient SMIC in place. Water injection MAY be needed when I move up my boost to 15 PSI. Remember I am running twins and am using a 360 thrust washer.

We won't know the validity of my theory until I get my fuel and tune done, and can make some reasonable recordings of my IAT with and without the fan in operation. I should also note that my IAT sensor is in the stock location so is likely to read higher than the actual IAT, especially in the situations I plan to reduce with this fan.

Thanks for reading and the input. Please any electrical gurus check out the schematic for me, and comment.

Thanks

 

Does your vehicle have the fan control mod that was installed with the factory recall? If so, you will have a different fan relay harness (in addition to the controller box at the back of the ECU) and you will need to reference a different schematic as there were changes to the fan relay wiring.

 

Thanks for the input, I do not have the fan control mod. I verified the schematic to my car before starting on this.

As stated I am using a PFC and controlling the fan with it. I am hoping that this turns out to be helpful.

 

How did you keep the fan on without turning on your lights?