Optimal Thermostat

GSTurbo1 · 07-10-2012, 12:54 PM

What recommendations would you guys have for a thermostat... I was thinking about taking mine down a little bit. I think it is mostlikely the stock one still on it.

TSiAWD666 · 07-10-2012, 01:01 PM

Oem.

GSTurbo1 · 07-10-2012, 01:18 PM

Don't go a little lower? My engine is built and pushing almost three times stock hp.

TSiAWD666 · 07-10-2012, 01:29 PM

Do you know at what temp makes peak torque? Probably not, and I'll bet a lot of money no one will post data showing it's not the oem's temp. If someone can show it's other than oem temp then that's when you might change, but in the absence of that data there's little point. In absence of the data I would trust the Mitsubishi engineers optimized the selected operating temp minimum (aka the thermostat temp) to be optimum for minimal wear on the engine and peak torque. Assuming that is the case, there's a good chance lowering the operating temp will not only lower your torque but also increase engine wear for no gain. I'm basing this on my readings in engine tuning, but I too have no data to justify my recommendation beyond my general theories on engine operation and assumptions on Mitsubishi's engineering capabilities.

GSTurbo1 · 07-10-2012, 01:32 PM

Good point... I was just curious because my temps have been rising. I want to check everything before I try to do the head gasket. I'm hoping something has blocked the tstat

red_devil · 07-10-2012, 02:04 PM

You want to keep temps between 195-205. My problem is that using the stock oem thermostat it opens just a little late and my temps start climbing to 215. Eventually the fans bring it back down to 205, but it just continues to go back and fourth. I'm going to swap it out for a 170 thermostat this weekend to see if that helps keep it a little lower, and adjust via coolant offset if its a little low. With engine temps over 215 and intake temps close to 100 degrees I'm loosing a lot of timing up top.

*edit* just realized your were running a 420a so it may not apply to you directly.

vl4bad · 08-22-2012, 02:57 PM

Quote:

Originally Posted by red_devil

You want to keep temps between 195-205. My problem is that using the stock oem thermostat it opens just a little late and my temps start climbing to 215. Eventually the fans bring it back down to 205, but it just continues to go back and fourth. I'm going to swap it out for a 170 thermostat this weekend to see if that helps keep it a little lower, and adjust via coolant offset if its a little low. With engine temps over 215 and intake temps close to 100 degrees I'm loosing a lot of timing up top.

*edit* just realized your were running a 420a so it may not apply to you directly.

did you ever find out if the 170 thermostat was better than the oem?

red_devil · 08-22-2012, 03:53 PM

Well the car runs cooler than it did but will still go up to 213 degrees in hot traffic, at speed it sits at 190. My main issue now is get a better flowing pusher fan. I think a 180 thermostat would be the best option. But a good working fans above all else.

jayson427 · 08-22-2012, 04:46 PM

Quote:

Originally Posted by TSiAWD666

Do you know at what temp makes peak torque? Probably not, and I'll bet a lot of money no one will post data showing it's not the oem's temp. If someone can show it's other than oem temp then that's when you might change, but in the absence of that data there's little point. In absence of the data I would trust the Mitsubishi engineers optimized the selected operating temp minimum (aka the thermostat temp) to be optimum for minimal wear on the engine and peak torque. Assuming that is the case, there's a good chance lowering the operating temp will not only lower your torque but also increase engine wear for no gain. I'm basing this on my readings in engine tuning, but I too have no data to justify my recommendation beyond my general theories on engine operation and assumptions on Mitsubishi's engineering capabilities.

you make a good point if what you read is good information but my question is why would they mass produce cooler running thermostats?? i run a 160 degree thermostat on my n/t built motor but i live in one of the hottest places around. im curious on the increasing engine wear tho. lowering my t-stat was highly recommened from an owner of a good aftermarket parts supplier for the 420a that i went through. i have had no issues with lower running temps so far and its been at least 3 months since i have had it in.

vl4bad · 08-22-2012, 05:03 PM

ok, alot of people have told me to go with the 170* im about to just order it honestly.

urbansmoker1 · 08-22-2012, 06:31 PM

Quote:

Originally Posted by vl4bad

ok, alot of people have told me to go with the 170* im about to just order it honestly.

It's like what.... 10 bucks. Get a few and test em out lol find which ever gets you at optimal temp. although if oem isnt keeping you there you could very well have something else goin on.

Mischif · 08-22-2012, 06:52 PM

I always go with the lowest temp one i can find. The way i see it, heat is a form of wasted energy, so the less the better. To a point at least. Hotter intake charges produce less power, hotter electronics tend to fail faster, so it only makes sense that a hotter engine will see more stress.

I like failsafe thermostats. Being stuck open and not allowing the engine to heat up is a million times better to me than one that gets stuck closed and fries the engine.

forumboarder154 · 08-22-2012, 07:04 PM

OEM. Cut jiggle valve off and drill the bleed hole to 1/8. Works great for me.