Ok, Before someone says research I have done my homework just need some double checking before I buy.

Car info: '87 Iroc 5.7 TPI dual fans

I am re doing my fans/cooling from the previous owners switches(which do not work). I have picked the dual fan controller from jegs on @185/off @ 170. http://www.jegs.com/i/JEGS+Performan...10570/10002/-1

Now with a 180 T-stat is this going to be hot enough, or should I get the other kit which kicks on @ 200/off @ 185 meant for a 195 T-stat. I know GM likes for them to run hot but I hate that and want to run around 180-195 degrees and have no worries.

Just making sure I wont be killing power and gas mileage. Any advice would be great!!

 

Why not just rewire it back to the stock setup and change the on/off fan temps with your PROM? You can save that $80 plus shipping and buy your own burning equipment (~$300), or get TunedPerformance to burn you a custom chip for your car if you don't want to get in on the chip burning yourself. All of this is assuming it can be put back to stock of course.

If not, I would go with the first one: on @ 185/off @ 170, and run a 180*F thermostat. The stock thermostats are 195*F I believe, so getting rid of that is probably the first step to a cooler running engine. Lower temps, though, will lower your gas mileage some, so heads up there; it will make your engine last longer though, so it's an even trade off...

 

Last owner pulled all the fan relays/wiring and tried to wire in toggle switches. So instead of tracking down OE fan components I was going to run this instead making it look stock.

 

It won't make much difference at all in terms of 185/170 fan switch vs 200/185 fan switch. Here is why.

The thermostat is largely irrelevant. If it's summer time (let's say 90°+ temps), it's going to be open after driving for 5 minutes and it will stay open. 160 thermostat? It will never close. 180 thermostat? It will never close. 195 thermostat? It might close if you're lucky. But if you're stuck in traffic during the heat of the afternoon, chances are the coolant temp will be 220° and that's with both fans on and the thermostat open.

The only time the thermostat temp choice really comes into play is on cold winter days. You'll never feel warm inside with a 160°. The 180° is good enough on days where it's near freezing outside. The 195° stat will make you feel super toasty and warm when it's freezing outside.

Here's the part that most people don't know about fan switches. They shut off once you go past 40 mph. The car relies on natural air movement through the air dam at highway speeds. Fans are off......So the fan switch really is for 0-40 mph speeds. What this means is that a fan switch that is 200/185 would need to be running at 184° or colder at speeds slower than 40 mph in order for the fans to shut off. But going slower than 40 mph (especially during summer), you're not going to ever see those temps. A fan switch that is 185/170 will flat out ALWAYS be on at speeds less than 40 mph even with a 160° thermostat (unless it's winter time and temps are frigid)

Let's take the extreme example of a 176/166 fan switch. They're recommended for 160° thermostats. But in reality, it doesn't matter if you have a 160, 180, or 195 thermostat. Because once that fan switch turns on, it will never shut off. (Remember we're talking about speeds less than 40 mph) There is no way you can get the car to run at 160-165° coolant temps with the fans off unless you live in Alaska or Minnesota and drive during winter (and who would run that fan switch in those climates anyways?)

So the bottom line is that it's your thermostat that sets the minimum operating temp. Not your fans. With any of the aftermarket fan switches, they're pretty much going to turn on the fan and then keep the fans on. The exception being a bitterly cold winter day.

I have a 180° thermostat and the 200/185 fan switch. When I shut the car off, 95% of the time I'll hear the fans spin down for a second or two. And that's ambient temps from 40° winter time to 100° summer time. It's quite rare to turn the car off and hear no fan at all.

 

My shorter answer is that I recommend the 200/185 fan switch to pretty much anybody. Reason being that at 200° and higher, you've got fans on. And by some chance if you do get the car down to 184° at city speeds, the fans will be off. The switch works good in wintertime because it let's the car heat up to 200° to get useable heat inside the cabin. It also works well during summertime hell because it doesn't take much to get to 200°. It seems like the perfect seasonal fan switch for winter, spring, summer, and fall. The car heats up enough to boil moisture out of the system.

On those rare winter days in the 30's, I sometimes wish I had the stock fan switch or else a 195° thermostat. But that's just because as I get older, I tend to prefer warmth more and cold temperature less. Fortunately we don't get too many days like that here.

 

Thanks for the info. I knew hotter was better up to a point but wasn't sure. 180 t stat and 200 switch it is then.

 

180 t stat
Toggle switch

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