Hi all.

I have a '93 coupe that is completely stock. I want to run a 180deg thermostat but I also want the to reprogram the chip to bring the fans on at around 200degs and off at about 180. I can find chips at some of the vendors such as SUMMIT that work for 180 thermostats but nothing about reprogramming the fans.

Do any of you know where to get the chip to accomplish the above? Oh yeah, I forgot one thing - I would like to keep the rest of the programming "Stock".

Any thoughts are greatly appreciated.

Thanks guys.

Norm.

 

www.pcmforless.com

 

Thanks, Rod.

I'll check them out.

Norm.

 

I believe the correct thermostat is a 180*. If you program the chip to those numbers the fans will never shut off because it will never get that cool with a stock radiator. Others have gone to a 160* stat, bigger radiator and lower the fan turn on point. This has worked for some but the LT1 is not designed to run at those low temperatures but higher. I just don’t think reprogramming will get you where you want to go.

Most LT1s with a normally operating cooling system should run about 200* on the road and normal driving unless stuck in stop and go traffic when its 90* outside. At that point the temp will definitely climb and only more air thru the radiator will help the cooling. A 160 or 180 stat will both be open at the point (the stat really sets the lowest operating temp).

In Florida here I run 193 to about 203 depending on outside temp. My radiator is slightly larger than stock which I replace with a 1 ¼ in thick GM replacement. Years ago I installed a fan switch to start the secondary fan when desired. If I get stuck in traffic when its hot and the temp is passing thru 210 on the way up I turn on the fan and it will cool it down and at least keep it stable for running up. As you know the vette will get hot even in cool temperatures when standing still and I don’t like it either.

I run my A/C 98% during the year so my primary fan is always running in street traffic. But in traffic that is not enough to keep it from heading up and I am not going to the 239* point so the secondary fan can kick on. I never go thru 220* and always watch it in summer time. Also most don’t know when on the expressway at 50+ MPH all fans will shut off. The software in the 94 PCM does this so as not the run the fans when lots of impact air is available. Not sure the 93 ECM does the same thing but I would suspect it might.

 

I have a '93 also and use a JET fan switch. You can view it at the Summit Racing link below. Not exactly the on/off temps you want but, it's an option other than chip. You can also install manual switch to turn fans on/off. Easy install as all you need is to ground relay connection so no 12v required at switch.

I also run without thermostat, 7 lb cap and Evans coolant with Meziere electric waterpump.

http://store.summitracing.com/partde...5&autoview=sku

 

pcolt94.

Thanks for your input. That is the kind of infomation that is helpful in deciding what to do. I think that the stock fans would not turn on because they are programmed to come on at 228 & 240 respectfully. What I want to to do is also have both fans programmed to come on at lower temps but still high enough not to stay on at all times. My current "Normal" running temps are in the 197-210 range so, it would seem to me that, with a 180 thermostat, the "Normal" temp would be a little lower because the stock thermostat starts to close at 195.

My biggest issue is that I don't like the engine running at 230 which is does now on hot days in slow traffic.

Thanks again for your thoughts.

Norm.

 

93lt1fun.

Thanks for the link. I've taken a look at it and it looks like what I might need to accomplish what I want.

Are you running the stock 195deg. thermostat or are you running a lower temp?

Thanks.

Norm.

 

As I mentioned previously I am not running a thermostat. I gutted the thermostat and only have the housing installed for a little water restriction. I also use a 7lb cap when stock I believe is 14lb. The reason I can do this is that I run Evans Coolant that has a 300+ deg boiling point and other characteristics that you can read about.
http://www.evanscooling.com/index2.html
The founder Jack Evans developed the LT1 reverse cooling system which GM stole from him.
http://www.evansvsgm.com/

I wouldn't worry to much about the 230 deg temps. Even with the coolant mod's I have I occasionally see 230 temps in the summer in Central, TX. There have been many forum threads regarding the higher then expected temps of LT1's with the similar conclusion that they were intended to run hotter for emissions. There was a recent article in Corvette Fever on this topic with the same conclusion.

P.S. I forgot to mention I also have a Griffin Aluminum radiator.

 

Once again, 93lt1fun, thanks for your response.

Norm.