I am going to program my fan(s) to come on at a lower temperature than that of the factory settings. I don't know what to set them to. I know I will get those that say why do that when the factory set them to come on at 230 degrees. Personally, I feel that keeping the engine a little cooler will prolong the life of the engine and everything else under the hood. I know not to go bellow 180 degrees.

So, what should it be?
Fan1 Turn on at --
Fan1 Turn off at--

Fan2 Turn on at--
Fan2 Turn off at--

Car is a 1995 LT1 with manual transmission. No upgrades. 180 degree Thermostat.

Thanks,
Chad

 

Shot for 195 on 190 off on fan one, and 200 on 196 off fan two.

Those temps will be fine, they are above the t-stat temp from the factory and will keep you out of reduced timing mode.

 

Have mine set at both on 205 off 200, stock thermostat.

 

You may be right about lower engine temps prolonging the life of the engine and underhood components, only time will tell. But since the LT1 was designed to run at a higher "normal operating temperature," I suggest:
Fan 1 on at 210
Fan 2 on at 220
Fans off at 205

 

I always use 84 - 89 Deg C, Increase the fan RPM from 3,600 - 4,100 Also you can change the oil temp fan settings via MPH. I force my fans on permanent via oil temp fan settings.

 

Temps suggested so far all sound ok. If you set too low the fans will run nearly all the time.

I have a 160 thermostat in my LT1 with an electric water pump. I was able to keep engine temp right around 180 but the fans were running almost all the time. I reprogrammed for 195 on and 185 off. Seems happier there, the fans cycle on/off rather than staying on to fight for a few less degrees that don't matter anyway.

 

I was going to ask about how to change the off temperature but read its the hysteresis that defines that.
By the way a will a definition (EE) be interchangeable between different software applications (ie tunerpro vs tunercat)?

 

I have mine set to 198 degrees with a 180 thermostat on an '85 L98. Works very well and I haven't had any problems with it that way. On very hot days it may climb a few degrees over 200 before dropping down but that is a very rare occurance.

 

My LT1 is running a 160* thermostat, which seems to set its minimum operating temperature floor at just above 170*F after it's warmed up. Its fans programmed as follows:

Primary fan on/off: 190/180
Secondary fan on/off: 195/185

Ideally, in terms of longevity you want the engine coolant to run somewhere around 180*F. Slightly cooler is fine, slightly warmer is fine. I prefer to keep mine cool. The 160* thermostat allowed me to set my fan-on/off temps where I want them, without forcing the fans to run constantly at idle and low-speed after warm-up.

IMHO, the benefits of lowering coolant temps are:

1. Much more headroom in the cooling system before Really Bad Things begin to happen if something goes wrong. If you lose system pressure when running at, say, 230*F, the coolant will probably immediately start to boil and vacate the premises, leading quickly to meltdown of engine parts. If you lose system pressure while running at, say, 180*F, the coolant will not boil away. If you suffer a major coolant loss (blown hose, etc), you'll have more time to react and get the car shut down before meltdown occurs if you're running at 180*F versus if you're running at 230*F.

2. Less stress on soft parts under the hood (belts, hoses, seals, gaskets, etc).

3. Reduced likelihood of detonation or having the ECM pull timing as a result of knock sensors going active.

Lowering the fan-on/off settings, in combination with a 160*F thermostat also will tend to stabilize coolant temps within a narrower operating range. Mine runs typically no lower than 171*F on the coldest days, and no higher than 200*F on the hottest days, and it tends to remain fairly stable.

The stock system allows temps to run anywhere from 190*F to 230*F or more, with a lot of cycling up and down within this range - undesirable, and just sloppy engineering, IMHO. It's clear that Chevrolet engineers weren't trying to force these engines to run at 230*F (if they were, they'd have put 220* thermostats in them), but it seems to have not bothered them much that, under some operating conditions, these engines would be allowed to run that hot. It bothers me, so I changed that.

And, in case anybody's wondering, yes, the heater works just fine when ECT is at 171*F on those really cold days.

As I see it, the benefits of running at the higher temps generated by a stock C4 cooling system are: None that I can think of.

Be well,

SJW

 

I like you reasoning!
So I was doing some reading and come across the parameter Fan Threshold High Speed. By default this is set to zero. Basically this is the speed of the car when the High Speed settings are used. If set to zero the high speed settings are always used.

Has anyone specified a speed other than zero here? If not than fans will be on at 10 mph or 100 mph. Does this matter?

https://www.corvetteforum.com/forums...-4-charts.html

 

You don't want the fans running if the car is moving above around 40MPH. I read somewhere (can't recall where) that if they're running at highway speeds, they'll actually impede airflow through the stack.

Live well,

SJW

 

I would agree with you but maybe I am missing something here. By default the parameter is 0 meaning the fans will run all the time when the temperature is high.

 

From my understanding there is not a setting that says OFF temperature. The OFF temperature is defined by the Hysteresis parameter. Mine by default are 6 and 4.5 degrees Celsius.
Note the 0 for speed high fan threshold.

I think i got it. working on some numbers now.

 

I left the stock settings on my 95 because living in Florida the a/c is always on and so are the fans

 

Not the definition file but the bin file will be.

 

New settings working great.

 

Pretty close here: both come on at 205 and off at 197.