Ok, thanks. That makes more sense now, although that is retarded since in an MSP, the driver's side only covers about a quarter of the radiator. It should be the other way around. Another lazy move by Mazda when converting the car to a MSP.
So I want to swap the control wires at the PCM so that the fan on passenger side turns on first, but of all things that are in the wiring diagram supplement, the fans aren't on there.
I have a patch harness for my megasquirt so I could swap them without cutting any wires on the car. If I can't figure it out, I'll just swap them over with some wires and some generic connectors.
As a side note, what kind of connectors do the SPAL slim fans come with? Do they match the stock connectors and come one of each since the connectors are different, or do they just come with a pig tail and require you to splice them in?
Ok realized supplement meant the main book should have it in there. The second fan appears to be called the condensor fan. It's signal comes from pin #45. The main fan is the cooling fan and it is controlled from pin #47.
I didn't swap the wires yet, but I put the cooling fan back in and it kicks on at 205 and within seconds the temp is back to 195 and it kicks off again, and the cycle repeats.
The condensor fan doesn't appear to come on until 235. When it does, it has apparently little affect on coolant temp. The temp kept climbing to 242 and I shut it down.
The condensor fan seems a lot weaker than the cooling fan, which is a shame since only 1/4 of the radiator is covered by the cooling fan. I think I am going to get some SPAL fans and run them both off the coolant fan control signal (just tap pin 45 to pin 47). I think this will really help with A/C performance when stopped too. I am not sure sure what other conditions turn on the condensor fan besides 235 degrees, but simply turning on the A/C didn't seem to kick it on.
So tonight I played with the fans a little while I was flushing and refilling my radiator. When the A/C is turned on, the condenser and cooling fan come on in cycles along with the compressor itself.
I don't know why cars cycle the A/C. It would probably work a lot better if it was left on, but perhaps it is preventing the evaporator from getting too cold. According to the manual there is a evaporator temperature sensor as well as a refrigerant pressure which either look like it can turn off the A/C.
So the old trick to cool your car down by turning on the A/C makes a little sense now, but would be nice if the fans didn't turn off when the evap got cold. I think I actually want either signal to turn on both fans. It also would be nice to just have a total override as well so I could flip them at will.
I just put a switch on them for $2 so I can turn them on whenever I want.
But if you are worried about coolant temp then there is something seriously wrong with your setup. Even the completely stock cooling system is not bad. msp or pro5. if you are overheating then something is wrong with your setup because lots of people making alot more power than stock use the stock cooling system without issue.
I agree the stock radiator and fans are pretty good in the MSP, I did notice a difference going to a full size Mishimotor rad and an FMIC but never had problems overheating with the stock rad even at the track (until it cracked). The stock fan is offset on the radiator to cool the SMIC, I can't imagine the SMIC without a fan on it!
max temp should be controlled by the thermostat, so unless you were overheating, what would be the difference ? Technically it probably made your car slower if it has more coolant capacity = more weight.. or more grip depending on how you look at it I guess. Either way I dont think you can go wrong with it.
the mishimoto does look nice ! especially if you are running the full width rad with a FMIC. I also always liked brian mp5ts triple pass rad as well (i think it was a ron davis or awr? either way it looked like it could handle serious track heating)
Difference is the fans hardly kick on after 20 minute sessions on track vs the stock radiator and fans they were on quite a bit. Mishimoto is $255 shipped the OEM is over $300.
The fan isn't offset to cool the SMIC. The fan is offset because it is the same fan setup as a regular protege. My complaint is that the cooling fan is only covering a 1/4 or so of the radiator.
I have a Ron Davis radiator and I do not have heat issues even on a hot AZ race track, except when I decided that the fan covering only a 1/4 of the radiator probably wasn't doing much and removed it, only to find out that it was the cooling fan and the other doesn't kick on unless the A/C is on or you hit 235 degrees, in which case I did have some overheating when stopped for any length of time.
