Adjusting Fan Temp Activation on LT1 350 OBD2
07-11-2023 | 09:24 AM
#1
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Joined: Jun 2022
Posts: 3
From: Nashville
Adjusting Fan Temp Activation on LT1 350 OBD2
Hey, Team!
I recently acquired a 1996 Z28/SS - love it. Never been happier. However, she naturally runs a little hotter than ideal. In my previous lt1 I had a switch, but this time I would like to try to adjust the temperature point that the fans turn on. Does anyone have any tips on how to adjust the fan speed through OBD2 and not OBD1. Ideally, I would love to figure out how to modify it myself so I can improve my personal skills. Thank you all!
I recently acquired a 1996 Z28/SS - love it. Never been happier. However, she naturally runs a little hotter than ideal. In my previous lt1 I had a switch, but this time I would like to try to adjust the temperature point that the fans turn on. Does anyone have any tips on how to adjust the fan speed through OBD2 and not OBD1. Ideally, I would love to figure out how to modify it myself so I can improve my personal skills. Thank you all!
07-11-2023 | 09:39 AM
#2
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Joined: Nov 1998
Posts: 70,853
From: Hell was full so they sent me to NJ
Re: Adjusting Fan Temp Activation on LT1 350 OBD2
Fan on/off temperatures are in the PCM program. You need programming software to flash the new temps into the program. Or you could have a mail order tuner make the change.
You could also find an old hand held Hypertech Power Programmer (HPP). Has the ability to alter fan on/off temperatures in the PCM. If you find an HPP, you have to make sure the previous owner reset the program in his PCM to stock, or else it won’t work on your VIN. The HPP has a few other useful features, but the “power program” is a dud.
What coolant temperatures are you seeing that you feel are “a little hotter than ideal”? The engine was designed to run at the midpoint of the dash gauge 210°F). Stock thermostat is 180°F. You could consider a 160° replacement and lower fan on/off temps. Might pick up a few HP, but will increase emissions slightly and may lose a fraction of an MPG.
You could also find an old hand held Hypertech Power Programmer (HPP). Has the ability to alter fan on/off temperatures in the PCM. If you find an HPP, you have to make sure the previous owner reset the program in his PCM to stock, or else it won’t work on your VIN. The HPP has a few other useful features, but the “power program” is a dud.
What coolant temperatures are you seeing that you feel are “a little hotter than ideal”? The engine was designed to run at the midpoint of the dash gauge 210°F). Stock thermostat is 180°F. You could consider a 160° replacement and lower fan on/off temps. Might pick up a few HP, but will increase emissions slightly and may lose a fraction of an MPG.
07-11-2023 | 10:04 AM
#3
Thread Starter
Registered User
Joined: Jun 2022
Posts: 3
From: Nashville
Re: Adjusting Fan Temp Activation on LT1 350 OBD2
Fan on/off temperatures are in the PCM program. You need programming software to flash the new temps into the program. Or you could have a mail order tuner make the change.
You could also find an old hand held Hypertech Power Programmer (HPP). Has the ability to alter fan on/off temperatures in the PCM. If you find an HPP, you have to make sure the previous owner reset the program in his PCM to stock, or else it won’t work on your VIN. The HPP has a few other useful features, but the “power program” is a dud.
What coolant temperatures are you seeing that you feel are “a little hotter than ideal”? The engine was designed to run at the midpoint of the dash gauge 210°F). Stock thermostat is 180°F. You could consider a 160° replacement and lower fan on/off temps. Might pick up a few HP, but will increase emissions slightly and may lose a fraction of an MPG.
You could also find an old hand held Hypertech Power Programmer (HPP). Has the ability to alter fan on/off temperatures in the PCM. If you find an HPP, you have to make sure the previous owner reset the program in his PCM to stock, or else it won’t work on your VIN. The HPP has a few other useful features, but the “power program” is a dud.
What coolant temperatures are you seeing that you feel are “a little hotter than ideal”? The engine was designed to run at the midpoint of the dash gauge 210°F). Stock thermostat is 180°F. You could consider a 160° replacement and lower fan on/off temps. Might pick up a few HP, but will increase emissions slightly and may lose a fraction of an MPG.
Okay! I see! I heard about HPP - just never knew that was an option for us.
I have an SLP 160°F thermostat ready for action and my intent was to aim for 200°F For low/210°F for High if I could figure out a way to adjust the PCM haha.
I appreciate you helping me so much!
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