Best thermostat for a tune?

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Yeret

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If one reflashes their computer with a 91 octane tune, does the operating temperature of the engine make any significant difference? When I had my engine gone through, I went with the OEM 195 degree thermo, but a lot of people who tune their engines use cooler ones (180 degrees seems common).

Just curious how much of a difference operating temperature will make in terms of tuned power.
 

dodge dude94

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It's only necessary if you get pinging at part and WOT with the tune.
 

MADDOG

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180 will help a bit but if you don't have efans then you can't change the temp settings on them so that sort of reduces the effectiveness of the lower temp tstat.
 

dudeman2009

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My old diesel instructor built race engines for extra cash in addition to teaching.
The point of running a colder t-stat is to allow the radiator to cool the engine during low load sections of track by staying mostly open when a standard tstat would be closed.

In both mine and his opinion, on a stock car or vehicles that don't see track use, have no place running tstats lower than 180F.

The colder an engine runs, the more wear it incurs, race engines don't care as most are rebuilt fairly often. Most low temp racing tstats are at or below 170F.

While the Tstat on these race engines trys to keep the engine at 170F or below, the engine never really drops that low at any point during the race as there is so much heat being produced when the engine is under load, the cooling system size is a science. Because there are parts of the engine that don't see coolant, but do see combustion (such as parts of the head in some DOHC designs) the coolant is desired to have a slightly lower temp in order to more quickly cool these areas.

In your engine I wouldn't run anything cooler than 180F, you are just going to wear out your rings and bearings faster. Personally I run 180F even though I don't get the best heat in michigan during the winter months is because I run a lot of low speed heavy towing in which i'll hit 210-230F on a regular basis, and a 180F operating temp helps cool everything down a bit faster.
 
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Gr8bawana

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I wondering how running a cooler t-stat would wear out your rings and bearing faster.
What is the theory behind this? Just wondering because I like to understand how things work.
 

dudeman2009

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I wondering how running a cooler t-stat would wear out your rings and bearing faster.
What is the theory behind this? Just wondering because I like to understand how things work.

The theory is that the colder metals do not embed as easily. One of the main functions of bearings is to provide a place for contaminates to embed themselves, this prevents scratching of the objects in contact with the bearing, such as the crankshaft and connecting rods. By design the bearings are of a softer metal than the rest of the engine.

Having everything run cooler means the metals in the engine are slightly more brittle, but more importantly, harder. A harder bearing surface resists embedding of contaminates, resulting in more marring of important load bearing surfaces. The rings are cooled by the water jacket lining the cylinder, if they do not get up to operating temperature they will not mate properly with the cylinder wall, resulting in extra blow-by and increased oil consumption. If the Piston itself is not allowed to warm up to operating temperature you end up with and oval of a piston in a curricular bore, this will greatly increase wear on the rings and piston skirt due to a phenomenon known as piston slap. Chevy's I6 they put in their blazers and trailblazers are known for their 'diesel knock' on cold starts for a minute until the piston warms up and becomes a circle.

In practice, problems won't usually appear for 60K miles and up, but it has been recorded to cause damage in as few as 10K miles.
 

Stegs

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i have 180 stat in my truck, with a sct tune

truck runs great and always cool
 
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Yeret

Yeret

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Interesting information guys. I've been thinking of switching to an electric fan, though I suspect I'll end up doing it AFTER a tune.

So, I'll probably just stick to the 195 since there doesn't seem to be much reason not to (other than potential spark knock). Also, I live in Iowa, so a pretty good part of the year is spent in balls-freezing temperature anyway.
 

dapepper9

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Interesting information guys. I've been thinking of switching to an electric fan, though I suspect I'll end up doing it AFTER a tune.

So, I'll probably just stick to the 195 since there doesn't seem to be much reason not to (other than potential spark knock). Also, I live in Iowa, so a pretty good part of the year is spent in balls-freezing temperature anyway.

I'm in western Iowa myself. Just loaded the latest update of FlyinRyans m1 canned tune as well. Run a Stant 195. No issues if your engine is up to *****
 
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