Before bashing the hyper tech chip, i am not looking for opinions on the chip itself, i am simply asking a question about the electric fan temp.

I am looking to find out what temp my electric fans will come on with a HYPERTECH THERMOMASTER chip PN 11542 for my 1985 auto z51 c4.

I know my stock one come ones a 225. I will be installing the thermomaster chip with a 180* thermostat. But i cannot find out what new temp the electric fan will come on with this chip.

does anyone know?

 

No one knows?

 

No idea. Seems like you could ask the Hypertech customer service people.

 

Did your car come with the auxiliary cooling fan? It is called B4P on the list of options in my 1988 L98, 700 R4 Corvette. If not sure look between cylinder #1 and #3 and there should be a one wire sensor there or if you don't have it there will be a plug in the hole. The Auxiliary cooling fan is a pusher fan and uses one wire to activate it. If you ground the green wire that goes to this sensor the fan should start automatically. I leave mine running when hot and it really helps. You can find sensor/switches in a variety of temperatures from 185* up that fit in that hole in the block.

I bought one of those chips and never installed it. I still have it someplace with the thermostat they want you to use with this particular chip. I will have to find it and test it to see what it REALLY does. Maybe I will make a couple runs with my stock chip and then swap and see if it gains or looses horsepower. I use a GTECH pro for verifying any modifications on my Corvettes. It is nice to "know" if the part really made a change...

I too would try to contact the folks at Hypertech who programmed that chip. If anyone would know for sure it would have to be them.

At least Hypertech is still in business and has been since 1985! Can't be THAT bad if they are still around thirty plus years later.....

Best regards,
Chris

 

Most tpi Hypertech turn the fan on at 99c . Off is controlled by vehicle speed iirc 35 mph.

 

(pretty sure) I had to replace the switch in the head when using that chip...it did come on much sooner, used a 160 stat also car ran noticably cooler which made the cost worth it..never expected more power that comes from within

 

Switch in the head is for the Dash Gage, one in the intake manifold is for the ECM


Yes, the PROM has the information that tells the computer when to turn the fans on. Combined with opening the thermostat at a lower temp and beginning the coolant circulation so heat can start being expelled. The ECM then controls the engine to a lower temp because the chip told it to and the coolant circulation starts lower than fan temp. I believe the fan temp was below factory Thermostat opening. IIRC, the Hypertech Chip had a fan on at 175*F, but that is based on trying to remember something from 20 years ago. Factory Thermostat was 195*F. So, if the thermostat isn't changed, you would just be cooling coolant sitting in your radiator until the thermostat opens... just wasting energy that would put additional load on the engine for no reason.

 

The thermomaster chip was meant to be used with a 160F thermostat. The fan comes on at 185F or so.