hey all,
I am an old (33) Mustang 5.0 guy here. I love my GS4 and want to know if any of you have done this tuner trick on a stock GS4. On my stang we switched thermostats from a 180 deg stock thermo to a 160 deg Robert Shaw performance thermo and at the same time I switched out the plugs for a plug that was one heat range cooler. At the same time we increased the gap on the plug from .44 to .54 if I remember right. The operating temp of my stang dropped dramatically 25% the car ran much cooler and i never had a problem fouling the plugs. Any help would be appreciated.

 

Welcome to CL, I am not as old, but I am a 5.0 enthusiest. Obvously, lower temps is nothing new to performance. There are a few different performance parts along these lines, however to get the "best" performance and emissions, its best that it runs at around 180-200 in order to control emissions and run effciently, not saying that this can't be altered for better performance more then emissions, however I think you will compromise one to get the other if any changes are made. I know on our 327 Corvette, they run 160*-170* thermostats to prevent them from running tooooo hot, however, a SBC running cool is something kind of rare... Search around and find out who makes what, plugs won't be a problem and I think Tom's or TRD makes a lower degree thermostat.

 

Funny thing.. Ltuned had the TRD thermostat just last night. Now I dont see it...

Here is the TRD link.

http://trdparts.jp/english/parts_thermostat.html

 

Thanks alot people.
When I had my stang I had off road exhaust so I wasn't concerned about emissions back then. Had the hook up on SMOGz. Anyways, thanks for the input guys.

 

I don't know if this is any help...but the trd stat is 160 degree, stock is 180 and you can go to schucks or o reilly's (whatever they are now) and pick up a 170 degree stat.

 

so a stock GS3 runs at 180 degrees?

 

The factory thermostat is more than what you'll need for everyday driving. While keeping the temp. low is key, the source of your power will be how your car breathes. A good insulated intake box with sufficient cool air and free flowing exhaust will net you good power.

 

I'm also a 5.0 fan, and a lot of 5.0 guys do change to colder termostat. All it really does is trick the ECU to run richer. They are programed to run richer until it meets the designated normal running temp. Correct me if I'm wrong.

 

Thats what I thought it would do. But I dont see gaining any real significant hp out of runing any richer than our already rich runing ecu does stock.

 

From what I understand, this was a trick long before electronic fuel injection. The main purpose is to keep the engine temp as low as possible as the hotter the engine gets the less it performs. Example would be forced induction, they run intercoolers to cool their air fuel mixture down to make the most power with denser air. I know that we had a problem with our radiator on our vette, and we couldn't get it to run below 210*, it would be sluggish, would run a little off, and def. no WOT performance like usual. After we fixed the leak, it runs at 180* all day, it no longer boils the fuel, it idles smooth, and there is a def WOT performance. Regarding our cars, since they are computer controlled, if the thermostat is too low, it will simply just stay in enrichment mode, which is almost "cold-start" mode. It will run rich to warm up faster, hense the high idle. Like you said, it will run in enrichment mode until Op temp, however if the thermostat is sent below op temp, you'll always be running in cold-start, not the best for performance, as usually the ECU doesn't give full timing advance when in cold-start. I think the coolant temp sensor would get close enough to not really harm performance, but with modern technology we no longer need to to do these tricks for performance as our technology is far better with aluminum radiators, e-fans, aluminum blocks, etc. Again, that being said a cooler engine will have more performance, very little, but every penny counts.... Just another man's rant, let me know what I missed.