Glazedham42

iTrader: (4)

I'll be using a 170 F coolant thermostat for my engine. I'm trying to decide which Painless fan kit I want for my electric fan....



I can have either:
185F on and 170F off
or
200F on 185F off

I would prefer to use the cooler fan thermostat, except I'm thinking that the fan will continue to run even when the thermostat is closed. It would be nice to have it kick on at 185F, but I don't want it to be running non stop because the thermostat closes and it can't ever cool down enough. Is letting the 12A get to 200F too hot? If I used that thermostat then the fan would kick off at 185F and let the radiator do its thing.....

What do you guys think?

85rx12a

i would go the 200-185

i have mine at 185-170 and my heater blow nuts...........freezing cold nuts.

Glazedham42

iTrader: (4)

I figure that the stock thermostat is 180F, so even if I go up to 200F that's probably where the stock fan clutch kicks in right??

85rx12a

im not ure the specs on the fan clutch. im sure its in my FSM but when i first fired my 85gs up she ran from 194 to 205 i was told that was pretty common.

trochoid

iTrader: (6)

Use the 185/170 of you're dead set on the Painless.. Using the higher one in stop and go traffic in the summer could allow the engine to get to hot. I bought the adjustable one from the local parts store for 25, along with a 30 amp relay. Since it's adjustable, I can set the fan to come on at whatever temp I choose. That is a much better choice imho than buying one that has preset on/off parameters.

Rotaryhaven

iTrader: (17)

I have used this particular one that trochoid says here. It is cheaper, easier and you can adjust it to whatever setting you want. It has been proven in at least 5 or 6 cars I've had on.

Glazedham42

iTrader: (4)

The factory service manual says the OEM theromstat fully opens at 203 F. I cant find the temperature when the stock clutch fan kicks in though. My thermostat would probably be fully open at 185 F, and the fan would kick on at 200 F. Wouldnt this still be cooler than the factory cooling fan setup??

Thanks for bouncing ideas back and forth guys...

Jamie

BTW: Im pretty set on using the painless thermostat kit. The quality of the kit is unmatched...

Siraniko

iTrader: (13)

thats a nice one and much better/more accurate than the ones with t-stat that goes into the radiator fins.

Glazedham42

iTrader: (4)

Wacky, what are your thoughts on using the 200F/185F thermostat? Is this too hot?

Siraniko

iTrader: (13)

Im very conservative when it comes to temp so I will get the lower range. The only advantage of having the hotter range is for fuel consumption in which none of my cars are capable of.

As I said, that kit is much better. It reminds me of my old 80's style t-stat with t-coupler inside the radiator hose===>>>it has large box so I dont use it.

I've also used the adjustable ones such as derale and those from parthouses but I had to set them low as its not really that accurate...observation using the autometer mechanical gauge with gutted t-stat housing. It worked but its just below my standard.

Glazedham42

iTrader: (4)

But if I went with the higher temp range I'm not going to be doing any damage, right?

Siraniko

iTrader: (13)

it wont cause any problem. it will just run cool all the time.

WackyRotary

Hey - were and how much was that thermostat control kit?

Glazedham42

iTrader: (4)

Summitracing.com, I think it's about $60.

Wacky, now I'm thoroughly confused. Even with the 200F= ON fan thermostat I'll be running cooler than usual?? I thought this would be a little bit on the hot side....

Jamie

vipernicus42

iTrader: (4)

185 On / 170 Off:
http://www.jegs.com/webapp/wcs/store...10002_52290_-1

200 On / 185 Off:
http://www.jegs.com/webapp/wcs/store...10002_52288_-1

Adjustable:
http://www.jegs.com/webapp/wcs/store...10002_96680_-1

Or you can search for "Painless thermostat" at jegs.com

I have the adjustable one with the probe that goes in the fins of the rad. I might consider the other ones though since they seem like they'd have a much more accurate read of the temp than the one I've got... I don't know if I like the non-adjustibility though. When I have my thermostat come on too low, the fan runs long after the car is off and drains the battery. If I got the other ones I'd have to wire it to an ignition-hot circuit, instead of an always-hot one, so then I wouldn't be going through my FC fuse block, I'd need another fuse and I'd need to find an ignition-on circuit in the engine bay.

Jon

Siraniko

iTrader: (13)

sorry, I mis-read it. the 200* should run fine.

Glazedham42

iTrader: (4)

Thanks Sensai....

mpk490p

where are you guys fitting the sensor? ideally i want to go in the back of the thermostat housing will this (http://www.summitracing.com/parts/PRF-30110/) fit that?
thanks
Mark

PercentSevenC

I'm running an adjustable Flex-a-Lite fan controller. $27 on Amazon and it seems to do its job. It has the type of probe that you shove into the radiator.

Hyper4mance2k

iTrader: (40)

200 should run fine, but i never let my water temps go above 190... I've used the adjustible derale controlers in teh past and they ******* suck. both have broke on me. Now I just run it to turn on when ever the ignition is on. Personally get one that's adjustable and set it to turn on at 180. On they dyno when you're tuning you can literally see there is a 2whp drop for ever 5 degrees above 180 that your oil gets. If you keep the water cool it'll help keep the oil cool. With normal ambiant temps of 75*F if my water temp is 180 my oil is always at 160. Once my water temps get to 190 the oil temps get to 180. And at 195 and above they seen to be equal. GHEY!!!

mpk490p

i run it with a switch at the minute so would just leave that hooked up for drag / track / dyno days but i like the idea of a thermostat that switches off at a lower temp then it switchs on just want to get one to fit in the thread in the thermostat housing
Mark

gsl-se addict

iTrader: (3)

Basically the 1st option would turn on if you ever hit 185F and then would probably never turn off (unless the engine was shut off).

The 2nd option would allow for large temperature swings. The T-stat is trying to maintain 170F, but the fan doesn't turn on until 200F, so in traffic, you would be hitting around 200F. Then fan will then come on and try to drop it to 185F. Once you were moving along again, you would drop to about 170F since you would have air flow through the rad without using the fan. So the temperature swing is about 30F or so in this case.

The 2nd option might be better, but I wouldn't bother using a 170F t-stat in this case. Get the OEM 180F t-stat for this option. This will allow a bit tighter regulation on your coolant temp. No sense in using a 170F t-stat if the fan is only on above 185 F (after it 1st hits the 200F mark).

The 1st option might be better if you were using a 160F t-stat or if it was say 190F on, 175F off with the 170F t-stat.

Kentetsu

I've been using a $18.00 adjustable controller that I got from Autozone for the last few years. Works great, and I get to set the fan to come on at the temp I desire. After a few days of tinkering with it, I got it set and haven't had to touch it since...

Hyper4mance2k

iTrader: (40)

just get an adjustable one and you'll be happy. seems like everyone else is. i'd buy another one if I could find one that didn't break on me. Don't buy the Derale ones.

elwood

iTrader: (1)

That is very surprising. As oil temps rise, viscosity decreases. The lower viscosity usually means more HP. The NASCAR guys generally like to keep their oil well above 200 deg so they can make more HP.

Is it possible you're seeing the HP loss because everything else is heating up, too? If the IAT increases in tandem with the oil temps, it would probably be more of a factor than the oil viscosity and be the real cause for the power loss.