I have a ZZ383 with 180 F thermostat. I have dual fans from Dodge Stratus and an aftermarket switch ( http://www.summitracing.com/parts/FLX-31165/ )that turn both fans on at the same time, slow at first but full after 10 degrees.
"They set fan speed from 60 to 100 percent, depending on the built-in thermostat's setting. The thermostats have a range of 160-220 degrees F."
Right now its adjusted to the lowest setting, 160 F.
So that brings me to the original question, when should I let the fans start (180 F like the thermostat?)?
"They set fan speed from 60 to 100 percent, depending on the built-in thermostat's setting. The thermostats have a range of 160-220 degrees F."
Right now its adjusted to the lowest setting, 160 F.
So that brings me to the original question, when should I let the fans start (180 F like the thermostat?)?
Senior Member
There are not many reasons to have the fans start before the thermostat opens and warm water enters the radiator.
Having the fans start at 180, switch off at 160 should be fine.
If the switch allows 2 different setups, maybe wire one to the A/C if available plus 210 on, 195 off, and the other one set at 185 on /170 off.
That's about 20 degrees lower then the stock setup for dual fan cars.
You could also stick with the sock setup.
Stock is something like 195 on and 234 on or somewhere along those lines. Not sure when the original fans go off again. I know they switch off when switching off the car. Some fan switches allow the fans to spin untill the set temperature is reached however
Having the fans start at 180, switch off at 160 should be fine.
If the switch allows 2 different setups, maybe wire one to the A/C if available plus 210 on, 195 off, and the other one set at 185 on /170 off.
That's about 20 degrees lower then the stock setup for dual fan cars.
You could also stick with the sock setup.
Stock is something like 195 on and 234 on or somewhere along those lines. Not sure when the original fans go off again. I know they switch off when switching off the car. Some fan switches allow the fans to spin untill the set temperature is reached however
Chevy86 IROC-Z
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May 13, 2026
When I aquired a BIN FIle for a 87 IROC-Z, the fan turn on was set at 220*. Thats factory setting too. I dont remember what temp the fans turn off though.
I dont want it to run that warm, its a carburated 383 with no emission check (and no ECM).
Senior Member
Quote:
This pretty much is your chosen operating temperature.Originally Posted by Nonni
I have a ZZ383 with 180 F thermostat. No reason in having the fans spin while there is no water flow through your rad, so anything under 180 as a starting temperature is not giving you a technical benefit
Supreme Member
I have a 180 deg themostat, The Prom is et to have the left fan turn on at start up and run up to 35 mph and the right one to come on with A/C running at 220 deg. In the city my car runs between 180/200 degs with the A/C and on the highway 170/180.
Chevy86 IROC-Z
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May 13, 2026
As for the adjustable fan switch, I bought one at Autozone for $20. It has one speed but it works great.